Google Translate is a free multilingual machine translation  service developed by Google, to translate text. It offers a website interface, mobile apps for Android and iOS, and an API that helps developers build browser extensions and software applications. Google Translate supports over 100 languages at various levels and as of May2017, serves over 500 million people daily.
Launched in April 2006 as a statistical machine translation service, it used United Nations and European Parliament transcripts to gather linguistic data. Rather than translating languages directly, it first translates text to English and then to the target language. During a translation, it looks for patterns in millions of documents to help decide on the best translation. Its accuracy has been criticized and ridiculed on several occasions. In November 2016, Google announced that Google Translate would switch to a neural machine translation engine - Google Neural Machine Translation (GNMT) - which translates "whole sentences at a time, rather than just piece by piece. It uses this broader context to help it figure out the most relevant translation, which it then rearranges and adjusts to be more like a human speaking with proper grammar". Originally only enabled for a few languages in 2016, GNMT is gradually being used for more languages.
History
Google Translation is a complimentary translation service developed by Google in April 2006.[3] It translates multiple forms of texts and media such as words, phrases and webpages.
Originally Google Translate was released as a Statistical Machine Translation (SMT).[3] Translating the required text into English before translating into the selected language was a mandatory step that it had to take.[3] Since SMT uses predictive algorithms to translate text, it had poor grammatical accuracy. However, Google initially did not hire experts to resolve this limitation due to ever-evolving nature of language.[3]
In January 2010, Google has introduced Android app and iOS version in February 2011 to serve as a portable personal interpreter.[3] As of February 2010, it was integrated into browsers such as Chrome and was able to pronounce the text, automatically recognize words in the picture and spot unfamiliar text and languages.[3]
In May 2014, Google acquired Word Lens to improve the quality of visual and voice translation.[4] It is able to scan text or picture with one's device and have it translated instantly. Moreover, the system automatically identifies foreign languages and translates speech without requiring individuals to tap the mic button whenever speech translation is needed.[4]
In November 2016, Google has transitioned its translating method to a system called “Neural Machine Translation.”[5] It uses Deep Learning techniques to translate the whole sentences at a time and ensures greater accuracy of the context.[3]
As of 2018, it translates more than 100 billion words a day.[5]
Functions
Google Translate can translate multiple forms of text and media, which includes text, speech, images, and videos. Specifically, its functions include:
Written Words Translation
A function that translates written words or text to a foreign language.[6]
Website Translation
A function that translates a whole webpage to selected languages[7]
Document Translation
A function that translates a document uploaded by the users to selected languages. The documents should be in the form of: .doc, .docx, .odf, .pdf, .ppt, .pptx, .ps, .rtf, .txt, .xls, .xlsx.[7]
Speech Translation
A function that instantly translates spoken language into the selected foreign language.[8]
Mobile App Translation
In 2018, Google Translate has introduced its new feature called “Tap to Translate,” which made instant translation accessible inside any apps without exiting or switching it.[9]
Image Translation
A function that identifies text in a picture taken by the users and translates text on the screen instantly.[10]
Handwritten Translation
A function that translates language that are hand written on the phone screen or drew on a virtual keyboard without the support of keyboard.[11]
For most of its features, Google Translate provides the pronunciation, dictionary, and listen to translation. Additionally, Google Translate has introduced its own Translate app, so translation is available with mobile phone in offline mode.[9]
Features
Google Translate can translate multiple forms of text and media, including text, speech, images, sites, or real-time video, from one language to another.[12][13] It supports over 100 languages at various levels[14] and as of May2017, serves over 500 million people daily.[15] For some languages, Google Translate can pronounce translated text,[16] highlight corresponding words and phrases in the source and target text, and act as a simple dictionary for single-word input. If "Detect language" is selected, text in an unknown language can be automatically identified. If a user enters a URL in the source text, Google Translate will produce a hyperlink to a machine translation of the website.[17] Users can save translations in a "phrasebook" for later use.[18] For some languages, text can be entered via an on-screen keyboard, through handwriting recognition, or speech recognition.[19][20]
Browser integration
Google Translate is available in some web browsers as an optional downloadable extension that can run the translation engine.[21] In February 2010, Google Translate was integrated into the Google Chrome browser by default, for optional automatic webpage translation.[22]
Mobile apps

The Google Translate app for Android and iOS supports more than 100 languages and can translate 37 languages via photo, 32 via voice in "conversation mode", and 27 via real-time video in "augmented reality mode".[25]
The Android app was released in January 2010, and for iOS on February 8, 2011.[26]
A January 2011 Android version experimented with a "Conversation Mode" that allowed users to communicate fluidly with a nearby person in another language.[27] Originally limited to English and Spanish, the feature received support for 12 new languages, still in testing, the following October.[28]
In January 2015, the apps gained the ability to translate physical signs in real time using the device's camera, as a result of Google's acquisition of the Word Lens app.[29][30] The original January launch only supported seven languages, but a July update added support for 20 new languages, and also enhanced the speed of Conversation Mode translations.[31][32]
API
In May 2011, Google announced that the Google Translate API for software developers had been deprecated and would cease functioning.[33] The Translate API page stated the reason as "substantial economic burden caused by extensive abuse" with an end date set for December 1, 2011.[34] In response to public pressure, Google announced in June 2011 that the API would continue to be available as a paid service.[35]
Because the API was used in numerous third-party websites and apps, the original decision to deprecate it led some developers to criticize Google and question the viability of using Google APIs in their products.[36][37]
Google Assistant
Google Translate also provides translations for Google Assistant and the devices that Google Assistant runs on such as Google Home and Google Pixel Buds.
Supported languages
The following languages are supported in Google Translate.[14]

Afrikaans
Albanian
Amharic
Arabic
Armenian
Azerbaijani
Basque
Belarusian
Bengali
Bosnian
Bulgarian
Burmese
Catalan
Cebuano
Chichewa
Chinese
Corsican
Croatian
Czech
Danish
Dutch
English
Esperanto
Estonian
Filipino
Finnish
French
Frisian
Galician
Georgian
German
Greek
Gujarati
Haitian Creole
Hausa
Hawaiian
Hebrew
Hindi
Hmong
Hungarian
Icelandic
Igbo
Indonesian
Irish
Italian
Japanese
Javanese
Kannada
Kazakh
Khmer
Korean
Kurdish (Kurmanji)
Kyrgyz
Lao
Latin
Latvian
Lithuanian
Luxembourgish
Macedonian
Malagasy
Malay
Malayalam
Maltese
Maori
Marathi
Mongolian
Nepali
Norwegian (Bokmål)
Pashto
Persian
Polish
Portuguese
Punjabi
Romanian
Russian
Samoan
Scots Gaelic
Serbian
Sesotho
Shona
Sindhi
Sinhala
Slovak
Slovenian
Somali
Spanish
Sundanese
Swahili
Swedish
Tajik
Tamil
Telugu
Thai
Turkish
Ukrainian
Urdu
Uzbek
Vietnamese
Welsh
Xhosa
Yiddish
Yoruba
Zulu

History
1st stage
English to and from German
English to and from Spanish
English to and from French
2nd stage
English to and from Portuguese
3rd stage
English to and from Italian
4th stage
English to and from Chinese (Simplified)
English to and from Japanese
English to and from Korean
5th stage (launched April 28, 2006)[38]
English to and from Arabic
6th stage (launched December 16, 2006)
English to and from Russian
7th stage (launched February 9, 2007)
English to and from Chinese (Traditional)
Chinese (Simplified to and from Traditional)
8th stage (all 25 language pairs use Google's machine translation system) (launched October 22, 2007)
English to and from Dutch
English to and from Greek
9th stage
English to and from Hindi
10th stage (as of this stage, translation can be done between any two languages, using English as an intermediate step, if needed) (launched May 8, 2008)
Bulgarian
Croatian
Czech
Danish
Finnish
Norwegian
Polish
Romanian
Swedish
11th stage (launched September 25, 2008)
Catalan
Filipino
Hebrew
Indonesian
Latvian
Lithuanian
Serbian
Slovak
Slovene
Ukrainian
Vietnamese
12th stage (launched January 30, 2009)
Albanian
Estonian
Galician
Hungarian
Maltese
Thai
Turkish
13th stage (launched June 19, 2009)
Persian
14th stage (launched August 24, 2009)
Afrikaans
Belarusian
Icelandic
Irish
Macedonian
Malay
Swahili
Welsh
Yiddish
15th stage (launched November 19, 2009)
The Beta stage is finished. Users can now choose to have the romanization written for Chinese, Japanese, Korean, Russian, Ukrainian, Belarusian, Bulgarian, Greek, Hindi and Thai. For translations from Arabic, Persian and Hindi, the user can enter a Latin transliteration of the text and the text will be transliterated to the native script for these languages as the user is typing. The text can now be read by a text-to-speech program in English, Italian, French and German.
16th stage (launched January 30, 2010)
Haitian Creole
17th stage (launched April 2010)
Speech program launched in Hindi and Spanish.
18th stage (launched May 5, 2010)
Speech program launched in Afrikaans, Albanian, Catalan, Chinese (Mandarin), Croatian, Czech, Danish, Dutch, Finnish, Greek, Hungarian, Icelandic, Indonesian, Latvian, Macedonian, Norwegian, Polish, Portuguese, Romanian, Russian, Serbian, Slovak, Swahili, Swedish, Turkish, Vietnamese and Welsh (based on eSpeak)[39]
19th stage (launched May 13, 2010)[40]
Armenian
Azerbaijani
Basque
Georgian
Urdu
20th stage (launched June 2010)
Provides romanization for Arabic.
21st stage (launched September 2010)
Allows phonetic typing for Arabic, Greek, Hindi, Persian, Russian, Serbian and Urdu.
Latin[41]
22nd stage (launched December 2010)
Romanization of Arabic removed.
Spell check added.
For some languages, Google replaced text-to-speech synthesizers from eSpeak's robot voice to native speaker's nature voice technologies made by SVOX[42] (Chinese, Czech, Danish, Dutch, Finnish, Greek, Hungarian, Norwegian, Polish, Portuguese, Russian, Swedish, Turkish). Also the old versions of French, German, Italian and Spanish. Latin uses the same synthesizer as Italian.
Speech program launched in Arabic, Japanese and Korean.
23rd stage (launched January 2011)
Choice of different translations for a word.
24th stage (launched June 2011)
5 new Indic languages (in alpha) and a transliterated input method:[43]
Bengali
Gujarati
Kannada
Tamil
Telugu
25th stage (launched July 2011)
Translation rating introduced.
26th stage (launched January 2012)
Dutch male voice synthesizer replaced with female.
Elena by SVOX replaced the Slovak eSpeak voice.
Transliteration of Yiddish added.
27th stage (launched February 2012)
Speech program launched in Thai.
Esperanto[44]
28th stage (launched September 2012)
Lao
29th stage (launched October 2012)
Transliteration of Lao added. (alpha status)[45][46]
30th stage (launched October 2012)
New speech program launched in English.
31st stage (launched November 2012)
New speech program in French, Spanish, Italian and German.
32nd stage (launched March 2013)
Phrasebook added.
33rd stage (launched April 2013)
Khmer
34th stage (launched May 2013)
Bosnian
Cebuano
Hmong
Javanese
Marathi
35th stage (launched May 2013)
16 additional languages can be used with camera-input: Bulgarian, Catalan, Croatian, Danish, Estonian, Finnish, Hungarian, Indonesian, Icelandic, Latvian, Lithuanian, Norwegian, Romanian, Slovak, Slovenian and Swedish.
36th stage (launched December 2013)
Hausa
Igbo
Maori
Mongolian
Nepali
Punjabi
Somali
Yoruba
Zulu
37th stage (launched June 2014)
Definition of words added.
38th stage (launched December 2014)
Burmese
Chewa
Kazakh
Malagasy
Malayalam
Sinhalese
Sotho
Sundanese
Tajik
Uzbek
39th stage (launched October 2015)
Transliteration of Arabic restored.
40th stage (launched November 2015)
Aurebesh
41st stage (launched February 2016)
13 more languages (Sindhi, Pashto, Amharic, Corsican, Frisian, Kyrgyz, Hawaiian, Kurdish (Kurmanji), Luxembourgish, Samoan, Scots Gaelic, Shona and Xhosa) were added into Google Translate.[47][48][49][50]
Aurebesh removed.
Speech program launched in Bengali.
Amharic
Corsican
Hawaiian
Kurdish (Kurmanji)
Kyrgyz
Luxembourgish
Pashto
Samoan
Scottish Gaelic
Shona
Sindhi[51]
West Frisian
Xhosa
42nd stage (launched September 2016)
Speech program launched in Ukrainian.
43rd stage (launched December 2016)
Speech program launched in Khmer and Sinhala.

Method of translation
In April 2006, Google Translate launched with a statistical machine translation engine.[1]
Google Translate does not apply grammatical rules, since its algorithms are based on statistical analysis rather than traditional rule-based analysis. The system's original creator, Franz Josef Och, has criticized the effectiveness of rule-based algorithms in favor of statistical approaches.[52] It is based on a method called statistical machine translation, and more specifically, on research by Och who won the DARPA contest for speed machine translation in 2003. Och was the head of Google's machine translation group until leaving to join Human Longevity, Inc. in July 2014.[53]
According to Och, a solid base for developing a usable statistical machine translation system for a new pair of languages from scratch would consist of a bilingual text corpus (or parallel collection) of more than 150-200 million words, and two monolingual corpora each of more than a billion words.[52] Statistical models from these data are then used to translate between those languages.
To acquire this huge amount of linguistic data, Google used United Nations and European Parliament transcripts.[54][55]
Google Translate does not translate from one language to another (L1 → L2). Instead, it often translates first to English and then to the target language (L1 → EN → L2).[56]
When Google Translate generates a translation, it looks for patterns in hundreds of millions of documents to help decide on the best translation. By detecting patterns in documents that have already been translated by human translators, Google Translate makes intelligent guesses as to what an appropriate translation should be.[57]
Before October 2007, for languages other than Arabic, Chinese and Russian, Google Translate was based on SYSTRAN, a software engine which is still used by several other online translation services such as Babel Fish (now defunct). Since October 2007, Google Translate has used proprietary, in-house technology based on statistical machine translation instead.[58][59]
Google Translate Community
Google constantly seeks for volunteers to be a part of its “Translate Community” to translate languages people speak and help improve Google Translate's accuracy.[60] There are two ways to contribute. First, Google will show a phrase then one should type in the translated version.[60] Second, Google will show all possible translation for a phrase for individuals to click the right translation.[60]
Statistical Machine Translation
Although, Google deployed a new system called “Neural Machine Translation” for better quality translation, there are languages that still use the traditional translation method called “Statistical Machine Translation.” It is a “rule-based” translation method that utilizes predictive algorithms to guess ways to translate texts in foreign languages.[61] It aims to translate whole phrases rather than single words then gather overlapping phrases for translation.[61] Moreover, it also analyzes bilingual text corpora to generate statistical model that translates texts from one language to another.[62]
Google Neural Machine Translation

In September 2016, a research team at Google led by the software engineer Harold Gilchrist announced the development of the Google Neural Machine Translation system (GNMT) to increase fluency and accuracy in Google Translate[2][63] and in November announced that Google Translate would switch to GNMT.
Google Translate's neural machine translation system uses a large end-to-end artificial neural network capable of deep learning,[2][64] in particular, long short-term memory networks.[65][66][67][68]
GNMT improves the quality of translation because it uses an example-based machine translation (EBMT) method in which the system "learns from millions of examples."[64] It translates "whole sentences at a time, rather than just piece by piece. It uses this broader context to help it figure out the most relevant translation, which it then rearranges and adjusts to be more like a human speaking with proper grammar".[2] GNMT's "proposed architecture" of "system learning" was first tested on over a hundred languages supported by Google Translate.[64] With the end-to-end framework, "the system learns over time to create better, more natural translations."[2] The GNMT network is capable of interlingual machine translation, which encodes the "semantics of the sentence rather than simply memorizing phrase-to-phrase translations",[64][69] and the system did not invent its own universal language, but uses "the commonality found inbetween many languages".[70] GNMT was first enabled for eight languages: to and from English and Chinese, French, German, Japanese, Korean, Portuguese, Spanish and Turkish.[2][63] In March 2017, it was enabled for Hindi, Russian and Vietnamese languages,[71] followed by Indonesian, Bengali, Gujarati, Kannada, Malayalam, Marathi, Punjabi, Tamil and Telugu languages in April.[72]
GNMT has the capability to translate directly from one language to another (L1 → L2), which improves upon the previous versions of Google Translate which first translated to English and then to the target language (L1 → EN → L2).[69] The GNMT system is also capable of Zero-Shot Translation - translating between a language pair (for example, Japanese to Korean) which the "system has never explicitly seen before."[64]
Crowdsourcing
In 2014, Google launched "Translate Community", a platform aimed at improving the translation service by seeking help from volunteers.[73][74] In August 2016, a Google Crowdsource app was released for Android users, in which translation tasks are offered.[75][76]
Accuracy
Although Google Translate is not as reliable as Human Translation, it has sufficient ability to provide relatively accurate translation and a gist of foreign language text. It has ability to translate text with the general use of words and phrases in a consistent manner.[77] A research conducted in 2011 showcased that Google Translate got slightly higher score than UCLA minimum score for English Proficiency Exam.[78] Due to its use of identical choice of words without considering the flexibility of choosing the alternative words or expressions, it produces relatively similar translation to human translation from the perspective of formality, referential cohesion, and conceptual cohesion.[79] Moreover, a number of languages are translated into the similar sentence structure and sentence length with the human translation.[79] Google carried out a test that required native speakers of each language to rate the translation with a scale between 0 and 6 and the results showed that Google Translate got 5.43 on average.[77]
Limitations
Due to the differences in complexity and nature of language, the accuracy vary greatly among languages.[80] Some languages produce better results than others. Typically, western languages such as English and Spanish are generally accurate, and the accuracy of African languages are often the poorest, followed by Asian and European languages.[81] Moreover, Google Translate performs well especially when English is the target language and the source language is from the European Union due to the prominence of translated EU parliament notes. A 2010 analysis indicated that French to English translation is relatively accurate.[82]
However, if the source text is shorter, rule-based machine translations often perform better; this effect is particularly evident in Chinese to English translations. While edits of translations may be submitted, in Chinese specifically one is not able to edit sentences as a whole. Instead, one must edit sometimes arbitrary sets of characters, leading to incorrect edits.[82] A good example is Russian-to-English. Formerly one would use Google Translate to make a draft and then use a dictionary and common sense to correct the numerous mistakes. As of early 2018 Translate is sufficiently accurate to make the Russian Wikipedia accessible to those who can read English. The quality of Translate can be checked by adding it as an extension to Chrome and applying it to the left language links of any Wikipedia article.
After the Google Translate has deployed a new technology called “Neural Machine Translation,” to translate whole sentences or text block in the context at a time, seeing the alternative translation for a word or phrase is not available anymore.[6] Moreover, in its “Written Words Translation” function, there is a word limit on the amount of text that can be translated at once.[6] Therefore, long text should be transferred to a document form and translated through its “Document Translate” function.[6]
Moreover, machine translation often does not identify the double meanings of a word.[83] A word in foreign language might have two different meanings in the translated language. As a result, it might lead to mistranslations.
Additionally, grammatical error remains as a major limitation that face Google Translate's attempts at accuracy.[84]
Reviews
Shortly after launching the translation service for the first time, Google won an international competition for English–Arabic and English–Chinese machine translation.[85]
Translation mistakes and oddities
Since Google Translate used statistical matching to translate, translated text can often include apparently nonsensical and obvious errors,[86] sometimes swapping common terms for similar but nonequivalent common terms in the other language,[87] or inverting sentence meaning. Novelty websites like Bad Translator and Translation Party have utilized the service to produce humorous text by translating back and forth between multiple languages, similar to the children's game telephone.[88]
Court usage
In 2017, Google Translate was used during a court hearing when court officials at Teesside Magistrates' Court failed to book an interpreter for a Chinese defendant.[89]
See also

Apertium
Babel Fish (discontinued; redirects to main Yahoo! site)
Comparison of machine translation applications
Google Dictionary
Google Text-to-Speech
Google Translator Toolkit
Jollo (discontinued)
List of Google products
Microsoft Translator
Reverso
SYSTRAN
Word Lens (discontinued; merged into Google Translate app)
Yandex.Translate

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The characterization of nanoparticles is a branch of nanometrology that deals with the characterization of physical and chemical properties of nanoparticles.  Nanoparticles have at least one primary external dimension of less than 100 nanometers, and are often engineered for their unique properties.  Nanoparticles are unlike conventional chemicals in that their chemical composition and concentration are not sufficient metrics for a complete description, because they vary in other physical properties such as size, shape, surface properties, crystallinity, and dispersion state.
Nanoparticles are characterized for various purposes, including nanotoxicology studies and exposure assessment in workplaces to assess their health and safety hazards, as well as manufacturing process control.  There is a wide range of instrumentation to measure these properties, including microscopy and spectroscopy methods as well as particle counters.  Metrology standards and reference materials for nanotechnology, while still a new discipline, are available from many organizations.
Background
Nanotechnology is the manipulation of matter at the atomic scale to create materials, devices, or systems with new properties or functions.  It has potential applications in energy, healthcare, industry, communications, agriculture, consumer products, and other sectors.  Nanoparticles have at least one primary external dimension of less than 100 nanometers, and often have properties different from those of their bulk components that are technologically useful.[1]  This article uses the broader definition of nanoparticles which includes all free nanomaterials regardless of their shape or how many of their dimensions are nanoscale;[2] this corresponds to the ISO/TS 80004 definition of "nano-object" rather than its more restrictive definition of nanoparticle, which only refers to round nano-objects.[3]
Nanoparticles have different analytical requirements than conventional chemicals, for which chemical composition and concentration are sufficient metrics.  Nanoparticles have other physical properties that must be measured for a complete description, such as size, shape, surface properties, crystallinity, and dispersion state.  These properties influence the health effects of exposure to nanoparticles of a given composition.  An additional challenge is that sampling and laboratory procedures can perturb the nanoparticles' dispersion state, or bias the distribution of their other properties.[4][5]
In environmental contexts, an additional challenge is that many methods cannot detect low concentrations of nanoparticles that may still have an adverse effect.[4]   A high background of natural and incidental nanoparticles may interfere with detection of the target engineered nanoparticle, as it is difficult to distinguish the two.[4][6]  Nanoparticles may also be mixed with larger particles.[6]  For some applications, nanoparticles may be characterized in complex matrices such as water, soil, food, polymers, inks, complex mixtures of organic liquids such as in cosmetics, or blood.[6][7]
Types of methods

Microscopy methods generate images of individual nanoparticles to characterize their shape, size, and location.  Electron microscopy and scanning probe microscopy are the dominant methods.  Because nanoparticles have a size below the diffraction limit of visible light, conventional optical microscopy is not useful.  Electron microscopes can be coupled to spectroscopic methods that can perform elemental analysis.  Microscopy methods are destructive, and can be prone to undesirable artifacts from sample preparation such as drying or vacuum conditions required for some methods, or from probe tip geometry in the case of scanning probe microscopy.  Additionally, microscopy is based on single-particle measurements, meaning that large numbers of individual particles must be characterized to estimate their bulk properties.[4][6]  A newer method, enhanced dark-field microscopy with hyperspectral imaging, shows promise for imaging nanoparticles in complex matrices such as biological tissue with higher contrast and throughput.[8]
Spectroscopy, which measures the particles' interaction with electromagnetic radiation as a function of wavelength, is useful for some classes of nanoparticles to characterize concentration, size, and shape.  Semiconductor quantum dots are fluorescent and metal nanoparticles exhibit surface plasmon absorbances, making both amenable to ultraviolet–visible spectroscopy.[4] Infrared, nuclear magnetic resonance, and X-ray spectroscopy are also used with nanoparticles.[6] Light scattering methods using laser light, X-rays, or neutron scattering are used to determine particle size, with each method suitable for different size ranges and particle compositions.[4][6]
Some miscellaneous methods are electrophoresis for surface charge, the Brunauer–Emmett–Teller method for surface area, and X-ray diffraction for crystal structure,[4] as well as mass spectrometry for particle mass, and particle counters for particle number.[6] Chromatography, centrifugation, and filtration techniques can be used to separate nanoparticles by size or other physical properties before or during characterization.[4]
Metrics
Size and dispersion

Particle size is the external dimensions of a particle, and dispersity is a measure of the range of particle sizes in a sample.  If the particle is elongated or irregularly shaped, the size will differ between dimensions, although many measurement techniques yield an equivalent spherical diameter based on the surrogate property being measured. Size can be calculated from physical properties such as settling velocity, diffusion rate or coefficient, and electrical mobility.  Size can also be calculated from microscope images using measured parameters such as Feret diameter, Martin diameter and projected area diameters; electron microscopy is often used for this purpose for nanoparticles.  Size measurements may differ between methods because they measure different aspects of particle dimensions, they average distributions over an ensemble differently, or the preparation for or operation of the method may change the effective particle size.[9]
For airborne nanoparticles, techniques for measuring size include cascade impactors, electrical low-pressure impactors, mobility analyzers, and time-of-flight mass spectrometers.  For nanoparticles in suspension, techniques include dynamic light scattering, laser diffraction, field flow fractionation, particle tracking analysis, size exclusion chromatography, centrifugal sedimentation, and atomic force microscopy.  For dry materials, techniques for measuring size include electron microscopy, atomic force microscopy, and X-ray diffraction.  Back-calculation from surface area measurements are commonly employed, but these are subject to error for porous materials.[9]  Additional methods include hydrodynamic chromatography, static light scattering, multiangle light scattering, nephelometry, laser-induced breakdown detection, and ultraviolet–visible spectroscopy;[4] as well as near-field scanning optical microscopy, confocal laser scanning microscopy, capillary electrophoresis, ultracentrifugation, cross-flow filtration, small-angle X-ray scattering, and differential mobility analysis.[6]  Use of an environmental scanning electron microscope avoids morphological changes caused by the vacuum required for standard scanning electron microscopy, at the cost of resolution.[4][6]
A closely related property is dispersion, a measure of the degree to which particles clump together into agglomerates or aggregates.  While the two terms are often used interchangeably, according to ISO nanotechnology definitions, an agglomerate is a reversible collection of particles weakly bound, for example by van der Waals forces or physical entanglement, whereas an aggregate is composed of irreversibly bonded or fused particles, for example through covalent bonds.  Dispersion is often assessed using the same techniques employed to determine size distribution, and the width of a particle size distribution is often used as a surrogate for dispersion.[9]  Dispersion is a dynamic process strongly affected by properties of the particles themselves as well as their environment such as pH and ionic strength.  Some methods have difficulty distinguishing between a single large particle and a set of smaller agglomerated or aggregated particles; in this case using multiple sizing methods can help resolve the ambiguity, with microscopy being particularly useful.[10]
Shape

Morphology refers to the physical shape of a particle, as well as its surface topography, for example, the presence of cracks, ridges, or pores.  Morphology influences dispersion, functionality, and toxicity, and has similar considerations as size measurements.  Evaluation of morphology requires direct visualization of the particles through techniques like scanning electron microscopy, transmission electron microscopy, and atomic force microscopy.[9]  Several size factors can be used, such as sphericity or circularity, aspect ratio, elongation, convexity, and fractal dimension.[5]  Because microscopy involves measurements of single particles, a large sample size is necessary to ensure a representative sample, and orientation and sample preparation effects must be accounted for.[10]
Chemical composition and crystal structure

Bulk chemical composition refers to the atomic elements of which a nanoparticle is composed, and can be measured in ensemble or single-particle elemental analysis methods. Ensemble techniques include atomic absorption spectroscopy, inductively coupled plasma optical emission spectroscopy or inductively coupled plasma mass spectrometry, nuclear magnetic resonance spectroscopy, neutron activation analysis, X-ray diffraction, X-ray absorption spectroscopy, X-ray fluorescence, and thermogravimetric analysis.  Single-particle techniques include time-of-flight mass spectrometry, as well as utilizing elemental detectors such as energy-dispersive X-ray analysis or electron energy loss spectroscopy while using scanning electron microscopy or transmission electron microscopy.[9]
The arrangement of elemental atoms in a nanoparticles may be organized into a crystal structure or may be amorphous. Crystallinity is the ratio of crystalline to amorphous structure. Crystallite size, the size of the crystal unit cell, can be calculated through the Scherrer equation.  Generally, crystal structure is determined using powder X-ray diffraction, or selected area electron diffraction using a transmission electron microscope, though others such as Raman spectroscopy exist.  X-ray diffraction requires on the order of a gram of material, whereas electron diffraction can be done on single particles.[9]
Surface area
Surface area is an important metric for engineered nanoparticles because it influences reactivity and surface interactions with ligands.  Different methods measure different aspects of surface area. Specific surface area refers to the surface area of a powder normalized to mass or volume. Different methods measure different aspects of surface area.[9]
Direct measurement of nanoparticle surface area utilizes adsorption of an inert gas such as nitrogen or krypton under varying conditions of pressure to form a monolayer of gas coverage.  The number of gas molecules needed to form a monolayer and the cross-sectional area of the adsorbate gas molecule are related to the "total surface area" of the particle, including internal pores and crevices, using the Brunauer–Emmett–Teller equation.[9]  Organic molecules can be used in place of gasses, such as ethylene glycol monoethyl ether.[4]
There are several indirect measurement techniques for airborne nanoparticles, which do not account for porosity and other surface irregularities and therefore may be inaccurate.  Real-time diffusion chargers measure the "active surface area", the area of the particle that interacts with the surrounding gas or ions and is accessible only from the outside. Electrical mobility analyzers calculate the spherical equivalent diameter, which can be converted using geometric relationships.  These methods cannot discriminate a nanoparticle of interest from incidental nanoparticles that may occur in complex environments such as workplace atmospheres.  Nanoparticles can be collected onto a substrate and their external dimensions can be measured using electron microscopy, then converted to surface area using geometric relations.[9]
Surface chemistry and charge

Surface chemistry refers to the elemental or molecular chemistry of particle surfaces.  No formal definition exists for what constitutes a surface layer, which is usually defined by the measurement technique employed.  For nanoparticles a higher proportion of atoms are on their surfaces relative to micron-scale particles, and surface atoms are in direct contact with solvents and influence their interactions with other molecules.  Some nanoparticles such as quantum dots may have a core–shell structure where the outer surface atoms are different than those of the interior core.[9]
Multiple techniques are available to characterize nanoparticle surface chemistry. X-ray photoelectron spectroscopy and Auger electron spectroscopy are well-suited to characterizing a thicker surface layer of 1–5 nm. Secondary ion mass spectroscopy is more useful to characterize just the top few angstroms, and can be used with sputtering techniques to analyze chemistry as a function of depth.  Surface chemistry measurements are particularly sensitive to contamination on particle surfaces, and quantitative analyses are difficult and spatial resolution can be poor.[9]  For adsorbed proteins, radiolabelling or mass spectrometry methods such as matrix-assisted laser desorption/ionization (MALDI) can be used.[10]
Surface charge generally refers to the charge from adsorption or desorption of protons on hydroxylated sites on a nanoparticle surface.[9]  Surface potential is difficult to directly measure, so the related zeta potential is often measured instead, which is the potential at the double layer's slipping plane, which separates mobile solvent molecules from those that remain attached to the surface.[4]  Zeta potential is a calculated rather than measured property, and is a function of both the nanoparticle of interest and its surrounding medium, requiring a description of the measurement temperature; composition, pH, viscosity, and dielectric constant of medium; and value used for the Henry function to be meaningful.  It is used as an indicator of colloidal stability, and has been shown to be predictive of nanoparticle uptake by cells.[9]  Zeta potential can be measured by titration to find the isoelectric point,[10] or through electrophoresis[4] including laser Doppler electrophoresis.[9]
Surface energy or wettability are also important for nanoparticle aggregation, dissolution, and bioaccumulation.  They can be measured through heat of immersion microcalorimetry studies, or through contact angle measurements.  Surface reactivity can also be directly monitored through microcalorimetry using probe molecules that undergo measurable changes.[10]
Solubility
Solubiity is a measurement of the degree to which material dissolves from a nanoparticle to enter solution.  Material dissolved as part of a solubiity test can be quantified using atomic absorption spectroscopy, inductively coupled plasma optical emission spectroscopy, and inductively coupled plasma mass spectroscopy, with the last being generally the most sensitive.  Two related concepts are biodurability, the rate of dissolution in a biological fluid or surrogate, and biopersistence, the rate at which a material is cleared from an organ such as the lung by physical and chemical dissolution processes.[9]
Analytical techniques for solubility quantitatively measure total elemental concentration in a sample, and do not discriminate between dissolved or solid forms.  Therefore, a separation process must be used to remove the remaining particles.  Physical separation techniques include size exclusion chromatography, hydrodynamic chromatography and field flow fractionation.  Mechanical separation techniques utilize membranes and/or centrifugation.  Chemical separation techniques are liquid–liquid extraction, solid–liquid extraction, cloud point extraction, and the use of magnetic nanoparticles.[9]
Applications
Product verification
Manufacturers and users of nanoparticles may perform characterization of their products for process control or verification and validation purposes.[9]  Unlike research-oriented nanometrology, industrial measurements emphasize reducing time, cost, and number of measured metrics, and must be performed under ambient conditions during a production process.[11]
Toxicology
Nanotoxicology is the study of the toxic effects of nanoparticles on living organisms.  Characterization of a nanoparticle's physical and chemical properties is important for ensuring the reproducibility of toxicology studies, and is also vital for studying how the physical and chemical properties of nanoparticles determine their biological effects.[10]
The properties of a nanoparticle, such as size distribution and agglomeration state, can change as a material is prepared and used in toxicology studies.  This makes it important to measure them at different points in the experiment.  The "as-received" or "as-generated" properties refer to the material's state when received from the manufacturer or synthesized in the laboratory.  The "as-dosed" or "as-exposed" properties refer to its state when administered to the biological system.  These may differ from the "as-received" state due to formation of aggregates and agglomerates if the material has been in powder form, the settling out of larger aggregates and agglomerates, or loss by adhesion to surfaces.  The properties may again be different at the point of interaction with the organism's tissues due to biodistribution and physiological clearance mechanisms.  At this stage, it is difficult to measure nanoparticle properties in situ without perturbing the system.  Post mortem or histological examination provides a way to measure these changes in the material, although the tissue itself can interfere with the measurements.[5]
Exposure assessment

Exposure assessment is a set of methods used to monitor contaminant release and exposures to workers.  It is a vital step in mitigating the health and safety hazards of nanomaterials in workplaces where they are handled.  For engineered nanoparticles, the assessment often involves use of both real-time instruments such as particle counters, which monitor the total number of particles in air (including both the nanoparticle of interest and other background particles), and filter-based occupational hygiene sampling methods that use electron microscopy and elemental analysis to identify the nanoparticle of interest.  Personal sampling locates the samplers in the personal breathing zone of the worker, as close to the nose and mouth as possible and usually attached to a shirt collar. Area sampling is where samplers are placed at static locations.[12]
The NIOSH Nanomaterial Exposure Assessment Technique (NEAT 2.0) is a sampling strategy that can be used to determine exposure potential for engineered nanoparticles.  The NEAT 2.0 approach uses two filter samples in the worker’s personal breathing zone and as area samples.  The first is used for elemental analysis.  The second is used to gather morphologic data from electron microscopy, which can provide an order of magnitude evaluation of the contribution of the nanoparticle of interest to the elemental mass load, as well as a qualitative assessment of the particle size, degree of agglomeration, and whether the nanoparticle is free or contained within a matrix.  Hazard identification and characterization can then be performed based on a holistic assessment of the integrated filter samples.  In addition, field-portable direct reading instruments can be used for continuous recording of normal fluctuations in particle count, size distribution, and mass.  By documenting the workers' activities, data-logged results can then be used to identify workplace tasks or practices that contribute to any increase or spikes in the counts.  The data need to be carefully interpreted, as direct reading instruments will identify the real-time quantity of all nanoparticles including any incidental background particles such as may occur from motor exhaust, pump exhaust, heating vessels, and other sources.  Evaluation of worker practices, ventilation efficacy, and other engineering exposure control systems and risk management strategies serve to allow for a comprehensive exposure assessment.[12]
To be effective, real-time particle counters should be able to detect a wide range of particle sizes, as nanoparticles may aggregate in the air.  Adjacent work areas can be simultaneously tested to establish a background concentration.[1]  Not all instruments used to detect aerosols are suitable for monitoring occupational nanoparticle emissions because they may not be able to detect smaller particles, or may be too large or difficult to ship to a workplace.[1][13]  Some NIOSH methods developed for other chemicals can be used for off-line analysis of nanoparticles,[1] including their morphology and geometry,[14] elemental carbon content (relevant for carbon-based nanoparticles),[15][16] and elemental analysis for several metals.[17]
Occupational exposure limits have not yet been developed for many of the large and growing number of engineered nanoparticles now being produced and used, as their hazards are not fully known.[12]  While mass-based metrics are traditionally used to characterize toxicological effects of exposure to air contaminants, it remains unclear which metrics are most important with regard to engineered nanoparticles.  Animal and cell-culture studies have shown that size and shape may be two major factors in their toxicological effects.[1]  Surface area and surface chemistry also appear to be more important than mass concentration.[13]  The U.S. National Institute for Occupational Safety and Health has determined non-regulatory recommended exposure limits (RELs) of 1.0 μg/m3 for carbon nanotubes and carbon nanofibers as background-corrected elemental carbon as an 8-hour time-weighted average (TWA) respirable mass concentration,[16] and 300 μg/m3 for ultrafine titanium dioxide as TWA concentrations for up to 10 hr/day during a 40-hour work week.[18]
Standards
Metrology standards for nanotechnology are available from both private organizations and government agencies.[19][20]  These include the International Organization for Standardization (ISO),[21][22] ASTM International,[23][24] the IEEE Standards Association (IEEE),[25] the International Electrotechnical Commission (IEC),[26][27] the International Union of Pure and Applied Chemistry,[28] the U.S. National Institute of Standards and Technology (NIST),[29]  the U.S. National Cancer Institute's Nanotechnology Characterization Laboratory,[30] and the European Committee for Standardization.[31]  The American National Standards Institute maintains a database of nanotechnology standards.[32]
Reference materials

Reference materials are materials that are established or produced to be homogeneous and stable in at least one measurable physical property to provide a control measurement.  Reference materials for nanoparticles can reduce measurement error that can contribute to uncertainty in their hazard properties in risk assessment.[33]  Reference materials can also be used for calibrating equipment used in nanoparticles characterization, for statistical quality control, and for comparing experiments run in different laboratories.[7]
Many nanoparticles do not yet have reference materials available.[4]  Nanoparticles have the challenge that reference materials can only be generated when the measurement methods themselves can produce precise and reproducible measurements of the relevant physical property.[33]  Measurement conditions must also be specified, because properties such as size and dispersion state may change based on them, especially when there is a thermodynamic equilibrium between particlulate and dissolved matter.[7]  Reference materials of nanoparticles often have a shorter validity period than other materials.  Those in powder form are more stable than those provided in suspensions, but the process of dispersing the powder increases uncertainty in its metrics.[4]
Reference nanoparticles are produced by the U.S. National Institute of Standards and Technology,[34] as well as the European Union Institute for Reference Materials and Measurements, the Japanese National Institute of Advanced Industrial Science and Technology, the Canadian National Research Council, the Chinese National Institute of Metrology, and Thermo Fisher Scientific.[33]  The German Federal Institute for Materials Research and Testing maintains a listing of nanoscale reference materials.[35]

What unit is used to measure nanoparticles?


Starscream is a fictional character in the many continuities in the Transformers franchise. He is one of the most frequently occurring characters in the Transformers fictional work, appearing in almost all continuities of the Transformers franchise. A graduate of the Cybertron War Academy, Starscream is a treacherous high-ranking Decepticon who turns into a jet fighter, and desires to replace Megatron as the leader of the Decepticons.
Fictional character biography
Authors have created many characters in the franchise based on the appeal of Starscream's treachery and cunning; most of these share his desire to lead the Decepticons. Starscream has the ambition to overthrow Megatron as the Decepticons' leader. He has controlled the Decepticons at times, but he usually suffers defeat. Starscream is ruthless, cruel, and more intelligent than average Decepticons, but also, unlikely to act directly on his aspirations without first securing conditions favorable to his ascension. He considers himself vastly superior to other Decepticons and finds Megatron contemptible for his antiquated military strategies and tactics.
Starscream believes the Decepticons should employ guile and speed more readily than brute force to defeat the Autobots. However, given the chance to lead, he is often less successful in this than Megatron. While Megatron frequently overlooks him as a threat, authors suggest such reasons for Megatron's tolerance of Starscream's presence as grudging respect for his scheming nature and precautionary observation. Others suggest that Starscream's treacherous nature is welcomed; that without a threat to his command, Megatron believes he would become soft and overconfident. Even so, Starscream often quickly exhausts Megatron's patience; violent-yet-brief verbal and/or physical conflicts between the two are not uncommon. As such, there have been times when Megatron has been close to killing Starscream, and on one occasion Starscream is only saved by a rockfall.
In his original appearance, Starscream transforms into a McDonnell Douglas F-15 Eagle. As Decepticon Air Commander, he leads the other Decepticon Seeker jets, many of whom share his physical design. His technical specifications indicate top speed as Mach 2.8 and altitude ceiling as 52 miles (84km). Launchers mounted on his arm (under his wings in jet mode) can deliver cluster bombs capable of leveling a 10,000 square feet (900m2) area and fire his signature null ray, which for brief periods disrupts the flow of electricity in any circuitry it contacts. This action temporarily renders inoperable any electronic device or machine, including Transformers.
Animated series
The Transformers
Starscream was formerly a scientist and explorer, working with the future Autobot Skyfire, during the Golden Age of Cybertron, shortly before the Autobot/Decepticon war re-erupted. Following the disappearance of Skyfire when the two were exploring a prehistoric Earth, Starscream returned to Cybertron and soon abandoned his scientific pursuits, becoming a warrior in Megatron's Decepticon army as the civil war exploded. Starscream attended the Cybertron War Academy, mentioned in the episode "A Prime Problem".
Starscream makes use of his old scientist profession in a few episodes. For example, when he and several other Decepticons were temporarily displaced in time to medieval England, the weapons of the transformers ceased functioning; Starscream knew how to use available materials to create gunpowder as a substitute for himself and the other Decepticons.[2]
In the episode "Starscream's Brigade", he attempts—in what was then only his latest in a series of attempts—to overthrow Megatron as the leader of Decepticons. After being defeated and exiled in Guadalcanal, Starscream finds the remains of some World War II military vehicles, which inspire him to create an army of his own. He travels to Cybertron using the Space Bridge, forcing the guards and eluding Shockwave to do so. He breaks into the Decepticon Detention Center and steals the five personality components of Renegade Decepticons, then installs them into five wrecked military vehicles and they become the Combaticons. The Combaticons (who combine to form Bruticus) and Starscream then capture four Transformers. When Megatron rallies his troops (except the Stunticons) against Starscream and the Combaticons, he deploys Devastator to fight Bruticus, but Devastator is defeated. Megatron attempts to retreat, however Starscream orders Bruticus to capture Megatron and hold him while he gloats and humiliates him. While this is going on, the Stunticons arrive, combine into Menasor and defeat Bruticus. Megatron orders Astrotrain to exile Starscream and the Combaticons to a distant planet, however they eventually return. After proving worth in battle, Starscream gets restored to Decepticon ranks and Megatron captures and reprograms Bruticus to obey only him.
In The Transformers: The Movie, Starscream and many other Decepticons participate in the battle of Autobot City, leaving several Autobots killed. After the Decepticons' defeat, they retreat in Astrotrain. In order to reduce Astrotrain's mass, the undamaged Decepticons had to jettison the heavily damaged Skywarp, Thundercracker, and the Insecticons into space, and Starscream ends up tossing Megatron, who had been mortally wounded from his fight with Optimus Prime, out of Astrotrain. After that he nominates himself as the new leader of Decepticons. However, during a grandiose coronation ceremony, Megatron, who has been reborn as Galvatron alongside Cyclonus, Scourge and the Sweeps, arrives, declares the coronation a "bad comedy". Starscream had barely a moment to realize that Galvatron was once Megatron, and Galvatron transforms into laser cannon mode, killing Starscream with a single shot.
However, while Starscream's body has been disintegrated, his "spark" remains as a ghost and returns later. In the episode "Starscream's Ghost", he is encountered by his old friend Octane in the Decepticon Crypt and conspires with him to hand Galvatron over to Rodimus Prime, the new leader of the Autobots. Starscream possesses Cyclonus's body and tricks Galvatron into being captured by the Autobots, however Galvatron escapes, returns and shoots Cyclonus, not aware that his second-in-command has been possessed by Starscream's ghost. The vengeful ghost easily escapes and re-appears in an additional episode, “Ghost in the Machine”. In the episode, he first appears possessing Scourge and reactivates the head of Unicron. Starscream then makes a deal with Unicron to restore the latter's sight and body by stealing the eyes of Metroplex and transformation cog of Trypticon, and wiring Unicron's head to Cybertron. Starscream successfully accomplishes most of this, however, when he can no longer possess Scourge, he demands that Unicron restore his own, original body so that he can complete the connections. Unicron complies and again demands that Starscream complete the connections, only to have Starscream double-cross him and tell him to "do it himself". At this point, the Autobots set off an explosion that blows Unicron's head and Starscream out into space. As Starscream tumbles out of control, he encounters the Decepticons who unleash all of their firepower on him, damaging him and pushing him farther into space.
Beast Wars
The G1 incarnation of Starscream returns in Beast Wars: Transformers, voiced by Doug Parker. In the episode "Possessed", He takes control of Waspinator's body following a lightning storm. The Predacons recognize him as Air Commander Starscream of the Decepticons. Starscream claims that he had been killed in battle defending Galvatron from Unicron, and pledges his allegiance to the Predacon leader Megatron. In reality, he was destroyed by Galvatron, and plots to usurp Megatron and take control of the Predacons. He captures the Maximal base, and later holds Optimus Primal and Dinobot hostage, ordering the Maximals to attack the Predacon base in exchange for their safety. He is defeated by the combined efforts of the Maximals and Blackarachnia, freeing Waspinator's body, and sending Starcream's ghost hurdling back into the depths of space.
Beast Wars II
In the Japanese-exclusive animated series, Beast Wars II, a character named Starscream was one of Galvatron's most loyal minions. Like the Decepticon air commander who came before him, Starscream is both ambitious and deadly. He makes up for his lack of size with unmatched speed and maneuverability. He hopes to one day dethrone Galvatron as the Predacon emperor of destruction and rule the universe himself. He is also slightly effeminate, often laughing and gesturing in a shaky way. When transformed Starscream becomes a stealth fighter capable of soaring at very high speed. In fighter mode he can use the "Formation Scream" and combine with his loyal partner BB to become a powerful air fighter, in which Starscream forms the rear of the combination. In robot mode his attack of choice are his "Screamwinder Missiles" which are strong enough to vaporize most opponents.  Starscream tries to undermine his equally treacherous rival Megastorm. Starscream, during an assassination attempt, accidentally turned Megastorm into Gigastorm. Gigastorm paid Starscream and BB back in kind, but exposure to Angalmosis energy turned them into Hellscream and Max B. As Hellscream, he has the beast mode of a cyborg shark, whilst Max B transforms into a cyborg wolf. Hellscream is last seen escaping the exploding Nemesis with Max B and Gigastorm. They do not reappear in Beast Wars Neo, leaving Hellscream, Max B, and Gigastorm's fates and activities unknown.
Unicron Trilogy

The Starscream of the "Unicron Trilogy" universe has gone through many notable changes in his personality as his story has progressed. At times he is quite similar to his G1 predecessor, but on many other occasions has displayed markedly different traits to his namesake.[3]
In "Armada", Starscream was a young arrogant warrior who desperately wished to gain the approval and respect of his leader Megatron (in contrast of his G1 counterpart), but started to become confused as he started to hate both himself and his commander for the abuse heaped upon him. He originally came to Earth as part of Megatron's expedition to gain the power of the Mini-Cons alongside Demolishor and Cyclonus. However, Starscream's frustration over having been made the last of the Decepticons to gain his partner Mini-Con led him to be manipulated by Sideways into battling with Megatron, which he lost.  His hatred for Megatron eventually led to him siding with the Autobots so he could bring his former leader down once and for all. During his time with the Autobots, he formed a surprisingly close friendship with the human Alexis. However, Thrust eventually manipulated Starscream into rejoining the Decepticons, though Starscream still vowed to destroy Megatron.
During the Unicron Battles, Starscream was one of the five Cybertronians who received a power boost from the Mini-Cons, giving him a new blue color scheme that makes him look like Thundercracker. Despite having the original G1 Thundercracker color scheme, Starscream was never renamed into the fellow seeker, but had stated "I look like Thundercracker" when he gained the new body colors. When Thrust was ousted as a servant of Unicron, Starscream reunited with Alexis and gave chase, though he ultimately failed to catch him. When Megatron, now calling himself "Galvatron", refused to acknowledge the existence of Unicron and the potential threat he carried, Starscream challenged his leader to a duel and allowed him to stab him in the chest with the Star Saber. After a final sendoff with Galvatron, the seeker pulled the Star Saber out of his chest, exposing his spark, and fired on Unicron directly, only for the Chaos Bringer to fire a bolt of lightning that completely disintegrated Starscream, killing him. Starscream's death ultimately convinced Galvatron of Unicron's existence and he allied the Decepticons with the Autobots to end the threat.
In Energon, set ten years later, Alpha Q revives Starscream and wipes all memories of his old life to use him as his personal assassin. However, Megatron eventually gets a hold of Starscream, using his newfound connection with Unicron to brainwash him into his loyal second-in-command. Later in the series, he is exposed to a pool of super energon, making his armor impervious to laser fire as well as recoloring it, making him resemble his original G1 colors. In the final episode, Starscream, along with Mirage, follows Galvatron into an energon sun, Galvatron having done so to break Unicron's hold over him.
Starscream returned again in Cybertron as a darker, more ruthless character. While he appears to be loyal to Megatron like he was in Energon, he secretly prepares a coup against him to become leader of the Decepticons. This results in a fracturing of the group, with Starscream discovering a group of ancient Decepticons, including two named Thunderblast and Lugnutz; he also recruits neutral Transformers Sideways and Soundwave. After several encounters, Starscream and Galvatron have one final battle which ends with Starscream, Soundwave, and Sideways being transported into another dimension. He is later located by Wing Saber, who teams up with Landmine and Mudflap to go after him.
Transformers: Animated
Starscream appears in the 2007 animated series, voiced by Tom Kenny. He transforms into a futuristic harrier jet, (sporting a notable similarity to the Variable Fighters of Macross fame in his transformation sequence) and resembles his Generation 1 counterpart in both design, personality, and ambitions. He flies at high speeds in both modes, and wields his trademark null-rays, though these function simply as powerful lasers. He's unintentionally comical in this incarnation displaying occasional incompetence. However, this incarnation displays a resolute tenacity towards his objective, shown by his flying around in a brutally damaged Nemesis to track down the Allspark's energy signature for 50 years by himself. Although slightly cowardly, Starscream is an excellent warrior, since he almost single-handedly took down all of the Autobots in a battle over the Allspark. He is more narcissistic than most incarnations of the character, frequently congratulating praising himself, his plans and his looks. During season 2, upon being resurrected by a shard of the Allspark embedded on his forehead, Starscream displays a sense of perseverance in the series, making numerous attempts to eliminate Megatron before and after being destroyed by the Decepticon leader. He also cannot tell the difference between any two humans.
In the Japanese translation of Transformers: Animated, the story has been changed to make it a prequel to the 2007 Transformers film. This makes this version of Starscream an earlier version of the film character.
Aligned series

Starscream is part of the main group of Decepticons in the 2010 computer animated series Transformers: Prime. This version is depicted as a much darker character, constantly plotting his rise to becoming the Decepticon leader and mercilessly killing Autobots, as evidenced when he terminates Cliffjumper in the series premiere.
He has displayed a contempt for Decepticons who do not choose a flying alternate mode, such as Knock Out. Although he may look weak, he is one of the deadliest Decepticons in history, using his clever skills and lethal weapons such as his missiles. Throughout the first half of season one, Starscream serves as the Decepticons' leader after Megatron is critically injured and placed on life support (aided in his injuries by Starscream's attempt to assassinate him). However, once Megatron revives, Starscream is beaten and punished, returning to his position as second-in-command.
Following Megatron's attempt to exterminate Starscream, as well as his further humiliation at the hands of the Decepticon Airachnid, Starscream leaves the Decepticons to strike out as an independent at the end of season one. His attempts to eradicate the Autobots and Megatron range from siding with the human terrorist organization M.E.C.H. (resulting in his loss of flight for most of season two) to cloning himself into an army, all of which end in failure, and he becomes more comedic in his ineptitude.
He eventually gains a powerful Iacon relic known as the Apex Armor, and also manages to obtain speed-enhancing red energon, though he loses the former to the Autobot Smokescreen. After learning of the Omega Keys, powerful Cybertronian relics that can be used to revive Cybertron, Starscream decides to steal the Keys from the Autobots and rejoin the Decepticons, at which he succeeds. Upon rejoining, Starscream regains his old position as Megatron's first lieutenant after the destruction of Dreadwing, and is instrumental in the kidnapping of the Autobots' human allies, the creation of the fortress Darkmount on Earth, and the destruction of the Autobot base.
In season three, Starscream is forced to share his high-ranking position with Shockwave, and tries to earn Megatron's respect by finding the Autobots before his rival, which results in an outbreak of energon vampires when he foolishly combines Dark Energon with unstable Synthetic Energon, resulting in the loss of over half of the Decepticon forces. Starscream is also distrustful of Predaking, the Predacon cloned by Shockwave to hunt down the Autobots, a feeling which is proven correct when Predaking shows he is sentient and capable of transforming. It is also he who suggests terminating the Predacon soldiers they have been creating, and blaming it on the Autobots, later causing Predaking to turn against them.
In "Deadlock", Starscream and the Decepticons fight the Autobots, and later witness Bumblebee slay Megatron with the Star Saber. Starscream, Shockwave and the other Decepticons then retreat.
In the TV movie Predacons Rising, which functions as the finale to the animated series Transformers: Prime, Starscream is shown to share leadership of the Decepticons with Shockwave, who constantly has them move labs to avoid detection. Starscream also helps to command two Predacons, Skylynx and Darksteel, they have cloned as part of their scheme to rebuild the Decepticon army, and is witness with Shockwave to the arrival of Unicron (possessing Megatron's upgraded and resurrected body). Starscream is among those to try and flee when Unicron attacks, but is betrayed by Knockout, who sides with the Autobots. When Megatron is freed from Unicron's control, Starscream is eager to rejoin him, but Megatron rebuffs, saying that he has lost his taste for inflicting oppression, and that the Decepticons are no more. Starscream then eagerly attempts to reinstate himself as leader of the Decepticons, but is confronted by Predaking, Skylynx and Darksteel, who are intent on revenge for their cruel treatment at his hands. Starscream's fate is left ambiguous.
The IDW comics for Transformers: Prime's sequel series Transformers: Robots in Disguise, revealed in its sixth issue that Predaking, Skylynx and Darksteel brutally attacked Starscream, as one of Starscream's arms was taken as a trophy by Predaking when he resettled on earth. The arm was later found by the Autobots Optimus Prime and Windblade. Starscream himself however survived, having escaped Skylynx and Darksteel and killed them inadvertently by setting off a room full of weapons that were capable of destroying even Predacons, in Darkmount on Cybertron. After reformatting his body, Starscream hid until he could regain his full power, tracking seven Minicons Megatron had been experimenting on to give himself even greater power than a Prime.[4] This led the Autobots to believe he was dead and allowed him to operate incognito. At some point after his escape, Starscream located the Weaponizer Minicons as part of his plans for revenge and galactic conquest and promptly began hunting them down, hiring an Insecticon, and two mercenaries named Roughedge and Shadelock to help him find the escaped Mini-Cons on Earth. He also came into possession of Megatron's Dark Star Saber and promptly took control of it, though the sword began rejecting him and he could not access its full power. Nevertheless, he still desired the Mini-Cons as part of his goals and ended up having Fixit, Jetstorm and Slipstream brought to him when they were captured by mistake. After learning that his old enemy, Bumblebee, was on Earth, he threatened to terminate the Minicons unless Bumblebee surrendered to him. Bumblebee promptly did so in order to secure their release. Unfortunately for Starscream, Optimus returned and defeated him while he was powered up by the Minicons. He took him and his team back to Cybertron and imprisoned them.[5]
Books
Starscream appears in the following books:
The 1984 sticker and story book Return to Cybertron written by Suzanne Weyn and published by Marvel Books.[6]
The 1984 sticker and story book The Revenge of the Decepticons written by Suzanne Weyn and published by Marvel Books.[7]
The 1985 Find Your Fate Junior book called Battle Drive by Barbara Siegel and Scott Siegel.[8]
The 1985 Transformers audio books Autobots' Lightning Strike, Megatron's Fight For Power, Autobots Fight Back and Laserbeak's Fury, as well as Galvatron's Air Attack from the 1986 series.[9]
The 1985 audio book Sun Raid.
The 1986 story and coloring book The Lost Treasure of Cybertron by Marvel Books.
Starscream was featured in the 1993 Transformers: Generation 2 coloring book "Decepticon Madness" by Bud Simpson.[10]
Starscream appears in the novel Transformers: Exodus,[11] and its sequels; Transformers: Exiles and Transformers: Retribution. Here he and the Seekers were the bodyguards of Sentinel Prime, but captured him and pledged their allegiance to Megatron when the war between Autobots and Decepticons broke out. Starscream proved to be a treacherous subordinate as usual, looking for every opportunity to play both sides to his advantage so that his circumstances would be favorable regardless of the outcome. In an attempt to see Megatron destroyed, he released Sentinel Prime so that the deposed leader could eliminate the leader of the Decepticons, only to see Sentinel Prime fall. Starscream attacked Megatron himself, but proved unable to defeat the Decepticon leader and was forced to submit to his authority again. He would join the crew of the Nemesis, and continue to seek Megatron's overthrow through a bargain with the Quintessons.
Comics
Marvel Comics
Serving as one of Megatron's elite troops in the attack on the Ark, the Marvel Comics incarnation of Starscream possessed the desire to take leadership of the Decepticons, but in the early days of the war on Earth, he did not accomplish any notable acts apart from nearly getting scrapped by Megatron after one snide comment. When he participated in an attack on the Ark with several of his fellow Decepticons, Starscream was deactivated by Omega Supreme, and sealed in a stasis pod in the Ark for a prolonged period of time.
At the same time, the U. K. offices of Marvel Comics were producing their own story-lines which were interspersed throughout the U.S. material. Simon Furman portrayed the character's scheming and ambition with more subtlety than the animated series, making Starscream more intelligent and cunning. He was often the focus of his own stories, including a Christmas special based around Starscream's misery at being stranded on Earth. In this story and in many others written by Furman, Starscream often came across as wry and sarcastic. He was one of the most formidable warriors in the Decepticon army and adversaries were often shown to be visibly intimidated by him.
Starscream made an appearance in the Decepticon forces under the command of Megatron in issue #7 of the Marvel Generation 2 comic series; in a story called "New Dawn" Megatron led his Decepticons against Jhiaxus' second generation Cybertronians near the moon of Tykos. The Decepticons were defeated and Megatron left injured, presumed dead, but swearing revenge.[12]
Fun Publications
Based on the Transformers Classics toy line, the Timelines 2007 story is set 15 years after the end of the Marvel Comics story (ignoring all events of the Marvel U.K. and Generation 2 comics). Megatron survived the crash of the Ark on Earth. He is joined by Starscream, who realized he needed a leader. In Transformers: Timelines volume 2 #2, "Games of Deception" Megatron detects the arrival of Bugbite's ship on Earth and sends Starscream, Skywarp and Ramjet to investigate. The three Seekers are then taken over by Bugbite's cerebro shells (with Starscream swearing to painfully dismember Bugbite for it). When the Autobots eventually jam the shells to facilitate their own rescue of Mirage, Starscream is freed and battles Bugbite's faction. Whether he survived the battle is unknown. He seems to retain his usual second-in-command status in this story.  Starscream reported to Deathsaurus on the success of the Combaticons' attack on the Autobot Elite Guard.[13]
Shattered Glass

This Starscream is a morally good version of the Generation 1 character from the BotCon exclusive "Shattered Glass" comic, in which the Decepticons are on the side of good and the Autobots on the side of evil. This version is loyal to Megatron, as opposed to his normally treacherous portrayal. He longs to return to his life as a scientist. Also, Megatron treats Starscream with far more respect and considers him a genius.
Starscream appears in the 2008 April Fool's comic Shattered Expectations by Fun Publications. He and Razorclaw confront his world's Goldbug, Grimlock and Jazz. When the Autobots refuse to surrender the Decepticons call in the Mayhem Suppression Squad.
Starscream then appears in the BotCon 2008 Timelines comic Transformers: Timelines story "Shattered Glass" as one of the troops of the heroic Decepticon Megatron. Starscream, Divebomb and Whisper drop "glass gas" bombs on the Autobot's Ark launch platform to make it vulnerable to attack.[14]
Starscream appears in the fiction Dungeons & Dinobots, a text based story from Fun Publications. He defends the Arch-Ayr fuel dump from an Autobot attack.[15]
The toy for the heroic Starscream is redeco of the Cybertron Voyager Starscream, and was available only at the 2008 BotCon. His color scheme is an homage to the Generation 1 Autobot Jetfire.
Transtech
Another incarnation of Starscream works in civil intelligence on Transtech Cybertron.[16] This Starscream appeared in the Fun Publications story "Transcendent", where he reported his findings on Skyfall and Landquake to Optimus Prime. Prowl and Starscream had a biographies printed by Fun Publications.[17]
Dreamwave Productions
In the 21st century re-imagining of the Generation One universe by the comics company Dreamwave Productions, Starscream remained his treacherous, power-hungry self. In the early days of the war on Cybertron, he devastated Iacon with a terraforming process, and went on to form his own faction called the Predacons when Megatron vanished in a space-bridge experiment.
Dreamwave Productions produced a companion comic for the G1 toyline just as Marvel Comics produced, it was different from the animated continuity. In these comics, the Armada incarnation of Starscream had a much smaller role, but was written in a fashion much closer to the original treacherous G1 character - a trait that would ultimately lead to his seeming demise when the Energon comic book began. He still possessed elements of the animated Armada Starscream, such as an unwillingness to shy away from battle.[18]
Starscream would appear in many of Megatron's subsequent schemes, including capturing Swindle, attempting to capture Mini-Cons for his own use and launching an attack on the Mini-Con base on the Moon. His next appearance would be 10 years after Unicron's defeat. When Starscream gatecrashed a meeting of the Terrorcons – renegade Decepticons who were unhappy with the peace between Autobot and Decepticon that had emerged in the wake of Unicron's defeat – at an energon plant, his mistake soon became apparent when he discovered that they had struck a deal with Unicron and gained new "Hyper Mode" powers. When their leader, Scorponok, arrived, Starscream was unable to talk himself out of trouble and was blasted into the plant's machinery by Scorponok, seemingly dying. But Starscream survived. The raw energon in the plant reacted in some mysterious way, giving him a ghostly body of pure energon (like the cartoon Energon version, this was also a homage to the ghost form of the original Starscream). In this form he ended up attacking Demolishor and draining him of his energy. Due to the collapse of Dreamwave, the series was stopped.[19]
Devil's Due Publishing
In this crossover from Devil's Due Publishing, the Ark was discovered by the terrorist Cobra Organization, and all the Transformers inside were reformatted into Cobra vehicles remotely controlled by the Televipers.
IDW Publishing

After Dreamwave's closure, the rights to the Transformers comics were taken up by IDW Publishing. Their version of the Generation One universe begins with a miniseries called The Transformers: Infiltration. His alternate mode here is that of an F-22 Raptor, foreshadowing the events of the 2007 live action movie.
Beast Wars Second Starscream had a biography printed in the Beast Wars Sourcebook by IDW Publishing.[20] IDW also published a one-shot Transformers story as part of their Deviations series that heavily featured Starscream: "'Til All Are One."
In this story, an alternate version of events from The Transformers: The Movie, Starscream took over leadership of the Decepticons after Megatron was killed by Optimus Prime. Thus, it was Starscream who first encountered Unicron and allied the Decepticons to him, after being upgraded by Unicron's power into the mighty Megascream. He briefly hunted the Autobots in an effort to destroy the Matrix of Leadership, but later turned against his benefactor when Unicron devoured one of Cybertron's moons, which Starscream saw as his own. When Unicron attacked Cybertron itself and Optimus Prime arrived to try and stop him, Megascream demanded that he hand over the Matrix, and combined with Astrotrain, Soundwave, Ramjet, and Dirge into a massive new form. However, Hot Rod soon arrived to rescue Optimus, and unleashed the power of the Matrix, resulting in Unicron's demise as well as that of Megascream and himself.
Combiner Wars
In conjunction with the Combiner Wars (Unite Warriors in Japan) line, Takara Tomy released a comic detailing how the Galvatronus combiner came to be. Following his defeat at the conclusion of The Headmasters, Galvatron's icy tomb was discovered by Cyclonus, whose body Galvatron modified to accommodate his own head in the chest compartment. Seeking a more fitting form, Galvatron directed Cyclonus to approach the disembodied head of Unicron, who was convinced to help Galvatron attain a combiner form with Cyclonus as its core. To accomplish this, Unicron used his power to open dimensional rifts in order to bring Curse Armada Thrust, Zombie War Breakdown, and Wandering Roller into their world. To Cyclonus' surprise, Starscream then made an appearance, expressing interest in joining this new alliance. Unicron promptly granted Starscream a new physical form, and Galvatron's head took control of his new minions to take on his new form of Galvatronus.[21]
Video games
Starscream appears as a playable character in Hasbro's Net Jet fighting game Transformers Battle Universe. Although other playable Transformers have several incarnations featured, the only playable incarnation of Starscream is the Generation 1 version.
In 2007, Starscream appears as a playable character in Activision's Transformers: The Game voiced by Daniel Ross. A color scheme of Generation 1 Starscream is available by completing the Decepticon Campaign. This scheme of G1 Starscream also appears as an unlockable bonus form for Create-A-Bot, and a Target exclusive for the Transformers: Decepticons DS game, and can be obtained by earning 2500 tokens through Wi-Fi play.
Starscream appears as a playable Decepticon character in the 2010 video game Transformers: War for Cybertron, voiced by Sam Riegel. He is playable in the level "Starscream's Brigade", is a boss in the autobot level "Defend Iacon" and is Megatrons opponent in the level "Dark Energon". His body type is available to use for the player's multiplayer custom decepticon scientist, although the body is arguably just that of a generic seeker. He is playable in escalation mode.
Starscream appears as a level boss in the Nintendo DS video game Transformers: War for Cybertron Decepticons. He appears again in the sequel Transformers: Fall of Cybertron. In Transformers: Prime - The Game, Starscream is present in the first level.
Starscream is among the characters appearing in the 2004 Transformers video game for the PlayStation 2. He appears as a level boss, battling the player's character at two points.[22]
Transformers Cinematic Universe

During production of the live-action film, writer Alex Kurtzman stated that Starscream would not stray from his treacherous roots as he seeks to overthrow Megatron, and frequently engages in arguments with him. In the first film, he is seen vehemently pledging his allegiance to Megatron when the latter breaks free from the Hoover Dam, but unlike the other Decepticons, he is not killed in the final battle and leaves Earth at the end of the movie. Starscream transforms into a Lockheed Martin F-22 Raptor. Starscream is armed with a rotary cannon, missile launchers and a saw. When in jet mode, he can simulate the presence of a human pilot, the same holographic model (referred to as "Mustache Man" on-set and in the credits) that "pilots" Blackout and "drives" Barricade. The actor is Air Force Major Brian Reece, a helicopter pilot instructor at Kirtland Air Force Base.[23]

Books
In the prequel novel Transformers: Ghosts of Yesterday, it is revealed that Starscream is the leader of the Decepticons following Megatron's disappearance during his search for the Allspark. He and a crew of Decepticons travel aboard the Nemesis to search for the Allspark and Megatron, although Starscream is more focused on finding the cube then his lost master. Blackout opposes him at every turn (rightly not trusting Starscream and thinking that he would prefer that they never find Megatron), while Barricade tolerates it only as a means of finding Megatron. Encountering Ghost-1, a human craft of Cybertronian design, Starscream manipulates them into revealing that Megatron and the Allspark are on Earth, then betrays them. After winning a fierce duel with Blackout for leadership, he launches a full-scale assault on the Autobots. Just as he and Bonecrusher almost kill Optimus Prime, Starscream is severely injured by Ghost-1. In retaliation, he destroys the human craft before retreating.[24]
Starscream returns in Transformers: The Veiled Threat. With Megatron dead, Starscream eventually returns to Earth around Zambia, where he gains control over local rebel groups by using his internal synthesizers to create gold coins.
IDW Publishing
The back story of the Transformers on ancient Cybertron is told in Transformers: Defiance. In this story, Starscream returns to Cybertron after encountering an enemy scout ship in the Eshems Nebula. After being repaired for minor damage by Ratchet, Starscream and Ironhide report to Optimus Prime and Megatron.[25] Later, the planet is invaded by aliens from the Eshems Nebula and Starscream is among the defenders in the city of Metrotitan, near the temple at Simfur. In issue #2, he sides with Megatron in his decision to counterattack Cybertron's invaders and is among the fleet that attacks their ships.
Starscream also appears at the end of issue #3 of Transformers: Movie Prequel, where he, Blackout and Barricade destroy the Mars Beagle probe. In issue 4, he travels to Earth, gaining his F-22 alternate mode by scanning an experimental Raptor before shooting it down.
He appears in the official movie sequel comic called "The Reign of Starscream".[26]
In Transformers: Rising Storm, it is shown that Starscream has broken away from Megatron's rule, and formed his own army - Club Starscream - with Barricade and some others under his command. However, after blasting his way past Ruination and Deadlift, Shockwave tells Starscream that Megatron requires his services. Shockwave then sends Starscream to recover the drone called Brains.[27]
Role in the films

In the first film, Starscream rallies the other Decepticons to battle once Frenzy alerts them to the All Spark's location. Starscream disguises as a F-22 Raptor providing cover for humans in Mission City and severely injures Bumblebee. After flying through the city, Starscream attempts to take the All Spark from Sam, but is later attacked by both Ironhide and Ratchet. Ironhide takes the most damage, while Ratchet was able to hold his ground against Starscream's attacks. He transforms back into jet mode and flies away, leaving Ironhide and Ratchet damaged. He then assist Megatron in going after the All Spark by shooting down the helicopter that was going to extract the Cube from Sam. Later, he attacks several F-22 Raptors flying through Mission City. Due to him transforming into a Raptor himself, Starscream was able to escape the jets as they were firing back at him. After Megatron was killed by Sam, Starscream retreats into deep space.
In the second film, Starscream is first seen aboard the Nemesis shipwreck and is confronted by a returning Megatron, angry that Starscream left him to die. Starscream explains that he and The Fallen engineered a new army of Decepticons, but reveals to Megatron that without sufficient energon levels to feed them, the hatchlings destined to become the new army will keep dying. Later in a factory near Sam's college, Starscream watches as Megatron plans to cut off Sam's brain and later Optimus Prime and Bumblebee arrives. Starscream joins Megatron and Grindor in a battle against Optimus Prime in the forest, which resulted in Optimus cutting off Starscream's right arm and ripping Grindor's head in half, however Megatron managed to kill Optimus by stabbing him in the back and shooting his spark out. Megatron and Starscream retreat as the Autobots arrive to save Sam. Megatron berates Starscream again after failing to capture the human. In the battle in Egypt, Starscream informs Megatron about the NEST soldiers and the Autobots planning to resurrect Optimus with the Matrix of Leadership. Starscream then leads the Decepticons on the hunt for Sam and Mikaela, sends Rampage after them, and leads the assault against the Autobots and NEST. After The Fallen was killed by super-mode Optimus Prime and Megatron was badly damaged, Starscream advises his leader to escape.
In the third film, Starscream first appears alongside Megatron, Soundwave, and Laserbeak in Africa. He gloats about Megatron's weakened state, which angers his master. In Washington DC, after Sentinel Prime betrayed the Autobots, Megatron and Starscream both witness Sentinel Prime bring an army of Decepticons to Earth from the Moon. He later shoots down the Autobot spaceship, the Xantium, after they have been exiled by the U.S. government. After the Autobots are thought to be dead, Megatron, Starscream, and Sentinel witness as the city of Chicago is being invaded and attacked by a massive Decepticon army. During the battle in Chicago, he meets Sam again and mocked him. Sam uses a grappling glove that was given to him by Que/Wheeljack to take out Starscream's right eye. Starscream then panics and sends Sam flying through the air then through a window of a nearby building. NEST soldiers led by Lennox arrive and they attack Starscream. Sam finally kills him using a boomstick given by Que/Wheeljack and stabs him in the other eye, blinding him and eventually blowing his head up.
In Transformers: Age of Extinction, a photo of Starscream appears with a red X indicating his death.
In Transformers: The Last Knight, Starscream's rebuilt head is shown being boasted by Daytrader, and later being held by Megatron.
Titan Magazine
In "Twilight's Last Greaming" part 3, Starscream and Scorponok attack the Autobots Arcee, Armorhide, Elita One, Longarm, Skyblast and Strongarm on the moon. Starscream would return in issue #22 of the Titan Transformers Magazine series in a story called "The Decepticon who Haunted Himself".
Video games
In the Nintendo DS Transformers: Decepticons game voiced by Daniel Ross, Starscream would kill Barricade and Blackout, and perhaps Brawl, who disappears after killing Ironhide, steal the Allspark and betray Megatron. Starscream is fought by Megatron as the final boss after he is heavily damaged and loses the AllSpark to Create-A-Bot. After being defeated, Megatron kills him for being a traitor, as well as Create-A-Bot for being weak. In the Autobots version he is a simple boss who ambushes Ironhide and the Autobot Create-A-Bot in the Arctic but retreats after a long battle and does not reappear or heard of again.
Starscream is among the playable characters in the 2009 Revenge of the Fallen video game by Activision.
In the Nintendo DS game, Revenge of the Fallen: Decepticons, Starscream was the temporary leader of the Decepticons until The Fallen forces him to revive Megatron.
Starscream appears in the 2011 Dark of the Moon video game. As a Hunter, he can be played on Xbox Campaigne and multiplayer[28]
Starscream is among the characters who appear in the TRANSFORMERS CYBERVERSE Battle Builder Game.[29]

Toys

The original Starscream toy was originally part of the Japanese Diaclone toy line and was designed by Kohjin Ohno in the early eighties. It was imported to become part of the Transformers toy line by Hasbro in 1984. The toy was later re-issued in Japan in 2001, with black-and-gold and translucent "ghost" variants, and again in 2003, redecorated into a more cartoon-accurate color scheme. He was also reissued in the west in 2003, with extended missiles to comply with safety regulations. Japan re-released Starscream once again in 2007 for their "Encore Series".[30] A highly prized collectable, the original Starscream toy has sold over $2000 on eBay.[31] The original Starscream toy was altered somewhat and an electronic sound maker was added for the Generation 2 toy line.[32]
Beast Wars Second Starscream had two toys produced exclusively in Japan. In 1997 he was released as a black redeco of Generation 2 Smokescreen. This same toy was recolored into Robot Masters Smokesniper. In 1998 he was released as "Hellscream", a remold of Beast Wars Cybershark. This second toy was eventually released with a slight color change in the US as Universe Overbite. Hellscream was voted the 9th strangest Transformers Beast Wars figure by Topless Robots.[33]
The Armada toy was the first new-mould Starscream figure since 1990, and it clung to tradition with a jet alternate mode and a robot form featuring many callbacks to the original Starscream figure, such as shoulder-wings, air intakes on the shoulders, a cockpit in the chest, and a head-sculpt designed to look like the original animated character. When the Mini-Con port on his backpack is pulled back and held, an electronic jet-take off noise is made. Attaching his Mini-Con partner Swindle to this port, however, unlocks his shoulder-mounted null laser cannons, and changes the sound to a repeating laser blast. Swindle can also mount under the jet-mode nosecone – by pressing the cockpit, Swindle is dropped to the ground with an accompanying electronic noise, while a press without Swindle attached yields more noises. In robot mode, Starscream's left wing can detach and unfold into a sword for him to wield.[34]
Starscream for the 2007 and 2009 movie had numerous toys released. He was one of two promotional figures released long before the 2007 movie as a "protoform". During the 2007 film release he was sold in various size classes as a licensed F-22 Raptor replica. These toys were recolored and released as fellow Decepticons Ramjet, Skywarp and Thundercracker. During the 2009 film he was released as both redecos of the 2007 film toys as well as new molds. All toys of this character are officially licensed from Lockheed Martin.
Animated Starscream also received numerous toys in many size classes during the run of the Animated toy line. Many of the Starscream toys were recolored as his clones Skywarp, Thundercracker, Ramjet, Dirge and Sunstorm. In 2008 a McDonald's Happy Meal was produced with a simple transforming Starscream toy inside to promote the series. This Starscream was also released in the Universe toy as a small Legends figure, shipping with a whole wave of tiny Animated characters. In Japan the Starscream figures were released in metallic finish by Takara.
Prime
Prime First Edition Deluxe Starscream (2011): An all-new mold of Starscream from the Prime animated series.[35]
Prime Cyberverse Commander Starscream (2012): A smaller scaled version of Starscream with translucent red arm cannons.
Prime Robots in Disguise Revealers Deluxe Bumblebee vs. Deluxe Starscream Entertainment Pack (2012)
Prime Voyager Starscream: A Voyager Class figure of Starscream with missiles and a null ray blaster.[36]
Generations Cybertronian Starscream (Deluxe, 2013)
Prime: Beast Hunters Deluxe Class Starscream with Clenching Thunder Talon(2013)[37]
Foreign names
Japanese: Starscream (スタースクリーム Sutāsukurīmu)
Cantonese: Sing Sing Giu (星星叫, "Star Shouting")
Hungarian: Üstökös ("Comet"), Csillagsikoly (Titan comics, "Starscream")
Indonesian: Teriakan Bintang ("Star Scream")
Mandarin: Tīen-wáng-hsīng (Taiwan, 天王星, "Uranus"), Hóng Zhīzhū (China, 紅蜘蛛, "Red Spider")
Ukrainian: Zorekryk (Зорекрик, "Dawnscream")
Latvian: Zvaigžņurīkle ("Starthroat")
Russian: Scandalist (Скандалист, "Brawler")

G1 Starscream at the Transformers Wiki