NANO TECHNOLOGY INSIGHT

General overview for Sri Lankan industrialists

A publication of the Technology Watch Centre, National Science Foundation

August 2006

WHAT IS NANOTECHNOLOGY

Nanotechnology is a relatively new field of research in scientific development, and involves manipulating and measuring rheological activities on a scale more than 800 times smaller than a human hair. Hence it is set to revolutionise science and technology..It has been speculated about for decades and the wonders and advantages of nanotechnology have been extolled by many. But not all.

Nanotechnology could be harmful to the environment or could be of benefit – depending on the priorities for research and development that are now being decided by Governments and companies. This booklet tries to explore the existing applications, and to analyse current trends and the associated incentives and risks.

Numerous existing technologies depend greatly on processes that take place on the nanometer scale.

Important nanomaterials used commercially include:

•Carbon tubes

•Titanium dioxide

•Silicon/germanium

•Calcium oxide-based materials

•Metal-cored coated particles

•Proteins or DNA

A Definition of Nanotechnology

Nanotechnology is the study, design, creation, synthesis, manipulation and application of functional materials, devices and systems through control of matter at the nanometer scale (1-100 nanometers, one nanometer being equal to 1X10-9 of a meter), that is at the atomic and molecular levels and the exploitation of novel phenomena and properties of matter at the scale.

A National Science Foundation, USA official has more precisely defined nanotechnology as a science that deals with materials and systems that have the following key properties:

•at least one dimension is from one 1 to 100 nanometres;

•the process of their design uses fundamental control over the physical and chemical attributes of molecular-scale structures; and

•they can be combined to form larger structures

Since the properties of matter depend in part on size, the physical, chemical and biological properties of matter generally differ at the nanoscale when compared to larger quantities of the same material. This is due, in part, to the difference in surface area per unit of volume at the nanoscale. For a given material, increasing the number of nanoscale. particles increases the proportion of atoms on the surface compared with the number of internal atoms.

The result is that chemical reactions can take place between atoms and molecules at surfaces. Essentially, nanoscale particles act as miniature chemical reactors.

In addition, other properties such as magnetism, hardness and electrical and heat conductivity can be changed substantially by modifying materials at the nanoscale. Atoms at the surface often behave differently from those located in the interior since they have a higher energy state.

CURRENT TRENDS – Applications

These changes arise from surprising collective and quantum size effects that arise from confining electrons in nanometre-sized structures While nanotechnology is in the "pre-competitive" stage (meaning its applied use is limited), nanoparticles are being used in a number of industries.

Nanoscale materials are used in

•electronic,

•magnetic and optoelectronic,

•biomedical, pharmaceutical,

•cosmetic, energy,

•catalytic and materials applications

Areas producing the greatest revenue for nanoparticles reportedly are chemical-mechanical polishing, magnetic recording tapes, sunscreens, automotive catalyst supports, biolabeling, electroconductive coatings and optical fibers.

Electronic applications

Today most computer hard drives contain giant magnetoresistance (GMR) heads, that through nano-thin layers of magnetic materials, allow for an order of magnitude increase in storage capacity. Other electronic applications include non-volatile magnetic memory, automotive sensors, landmine detectors and solid-state compasses.

Catalytic and material applications

Nanoparticles also are being used increasingly in catalysis, where the large surface area per unit volume of nanosized catalysts enhances reactions.

Greater reactivity of these smaller agents reduces the quantity of catalytic materials necessary to produce desired results. The oil industry relies on nanoscale catalysts for refining petroleum, while the automobile industry is saving large sums of money by using nanosized – in place of larger platinum particles in its catalytic converters.

Because of their size, filters made of nanoparticles also have been found to be excellent for liquid filtration. Several products are now available for large-scale water purification that can take out the tiniest bacteria and viruses from water systems, in addition to chemicals and particulate matter.

Nanomaterials, which can be purchased in dry powder form or in liquid dispersions, often are combined with other materials today to improve product functionality. Another example of rapid insertion of nanotechnology into useful applications is in the field of wear-resistant coatings. In the mid-1990s, nanoceramic coatings exhibiting much higher toughness than conventional coatings were first developed. In 2000, the first nanostructured coating was qualified for use on gears of air-conditioning units for U.S. Navy ships. It is estimated that use of the coatings on air valves will result in a $20 million reduction in maintenance costs over 10 years. The development of wear-resistant coatings will lead to commercial applications that can extend the lifetime of moving parts in everything from personal cars to heavy machinery.

CURRENT TRENDS – Applications

Energy applications

Chinese and American scientists have developed a method of storing high quantities of hydrogen inside tiny tubes of carbon just two nanometres across. The development is another step in the search for technical solutions to the problems that currently prevent hydrogen from being used as a practical everyday fuel.

The gas produces no pollution and no greenhouse emissions when burned in pure oxygen and is considered by many to be the clean energy of the future and a replacement for fossil fuels when current reserves run out. Technology Cambridge, US, has demonstrated an effective way to absorb hydrogen into carbon nanotubes – minute cylinders made of carbon atoms.

Cosmetic applications

Addition of Nano particles add high chemical purity, reduce toxic content, prevents ultraviolet absorption, mild, safe and no stimulations to human skins

• Currently used in sunscreen

• Currently used in foundation makeup products

• Currently used in face cream and moisturizer beauty products

Food industry applications

•Currently, the value of nanotech in food is driven by the use of nanoclays in food packaging and the development of improved nutraceuticals. There is also some commercial activity of nano-related technologies being used in food processing such as filtration.

•Silica particles are added to ice cream, ketchup and tooth paste as filler or an abrasive

Biomedical, pharmaceutical applications

Medical diagnosis with appropriate and effective delivery of pharmaceuticals are the medical areas where nanosized particles have found practical applications. However, there are many other interesting proposals for the use of nanomechanical tools in the fields of medical research and clinical practice. Such nanotools are awaiting construction, and presently are more like a fantasy. Nanodevices in medical sciences could function to replace defective or improperly functioning cells, such as the respirocyte proposed by Freitas. Man-made red blood cell is theoretically capable of providing oxygen more effectively than an erythrocyte. It could replace defective natural red cells in blood circulation. Primary applications of respirocytes may involve transfusable blood substitution, partial treatment of anaemia, prenatal/neonatal problems, and lung disorders.

CURRENT TRENDS – Applications

It has been reported that nanomachines could administer drugs within a patient's body. Such nanoconstructions could deliver drugs to peculiar sites making treatment more accurate and precise. Similar machines with specific "weapons" could be used to remove obstacles in the circulatory system or in the identification and killing of tumour cells.

The other vital applications of nanotechnology in relation to medical research and diagnostics are nanorobots. Nanorobots operating in the human body could monitor levels of different compounds and record the information in the internal memory.

They could be rapidly used in the examination of a given tissue, surveying its biochemical, biomechanical, and histometrical features in greater detail. Just as biotechnology extends the range and efficacy of treatment options available from nanomaterials, the advent of molecular nanotechnology will again expand enormously the effectiveness, comfort and speed of future medical treatments while at the same time significantly reducing their risk, cost, and invasiveness.

Automotive applications

•Mercedes-Benz developed nano-particle clearcoat to offer significantly greater scratch resistance and improved gloss

•Ford, GM, Toyota implement nanocomposite polymeric materials as stronger substitute for steel, aluminum or composite in body panels

•Electroconductive polymers have also been developed for exterior body panel applications, where body panels use the same electrostatic paint line as for the steel components they replace

Environmental applications

•Opportunities to develop efficient and effective nanomaterial filters for water and air, leading to reduced pollution

•Opportunities for other pollution control technologies, e.g. improved catalysts composed of nanoparticles are already in use in petrol and chemical processing, resulting in less waste in these processes.

Aerospace materials

Objects made from nanomaterials could be up to 100 times lighter, using 100 times less of the same substance. By substituting diamondoid composite material, this factor could be increased to about 250. As a result, ultralight cars, trucks, trains, aircraft, and spacecraft would use far less energy, especially with atomically smooth surfaces to reduce internal friction and air resistance losses. Space transportation costs could be reduced considerably with the products of nanotechnology.

CURRENT TRENDS – Applications

Nanotechnology is everywhere

Nanotech is not just a lab experiment anymore. It is spreading fast and in some surprising ways. For that matter, one may probably slather nanotech all over the face in summer. It is in sunscreens and sun-blocking lotions. It is in quick-drying paint. It might be in your pants.

Perhaps most dazzling of all, nanotechnology can be used to manufacture diamonds that are all but indistinguishable from mined diamonds - a profound development that could eventually cut into traditional diamond sales the way Tylenol pushed aside aspirin.

Additional products available today that benefit from the unique properties of nanoscale materials, include:

•Step assists on vans and bumpers on cars

•Paints and coatings to protect against corrosion, scratches and radiation

•Protective and glare-reducing coatings for eyeglasses and cars

•Metal-cutting tools, ink and automobile catalytic converters.

•Sunscreens and cosmetics

•Longer-lasting tennis balls, light-weight, stronger tennis racquets

•Stain-free clothing and mattresses

•Dental-bonding agent, burn and wound dressings

THE FUTURE OF NANOTECHNOLOGY

The future generations of nanotechnology will rely on being able to effectively arrange atoms. Molecular manufacturing and the use of molecular assemblers to hold and position molecules will be key to the future, and controlling how molecules react will allow scientists to build complex structures with atomically precise control.

The future of technology is sometimes easy to predict. Computers will compute faster, materials will become stronger, and medicine will cure more diseases. Nanotechnology, which works on the nanometer scale of molecules and atoms, will be a large part of this future, enabling great improvements in all these fields.

Advanced nanotechnology will work with molecular precision, making a wide range of products that are impossible to make today. Molecular manufacturing is the use of programmable chemistry to build exponential manufacturing systems and high-performance products. There are several ways in which this can be achieved, each with its own benefits and drawbacks. This technology is coming soon – almost certainly within 20 years, and perhaps in less than a decade. When it arrives, it will come quickly. Molecular manufacturing can be built into a selfcontained, tabletop factory that makes cheap products efficiently at molecular scale.

THE FUTURE OF NANOTECHNOLOGY

The future generations of nanotechnology will rely on being able to effectively arrange atoms. Molecular manufacturing and the use of molecular assemblers to hold and position molecules will be key to the future, and controlling how molecules react will allow scientists to build complex structures with atomically precise control.

The future of technology is sometimes easy to predict. Computers will compute faster, materials will become stronger, and medicine will cure more diseases. Nanotechnology, which works on the nanometer scale of molecules and atoms, will be a large part of this future, enabling great improvements in all these fields.
Advanced nanotechnology will work with molecular precision, making a wide range of products that are impossible to make today. Molecular manufacturing is the use of programmable chemistry to build exponential manufacturing systems and high-performance products. There are several ways in which this can be achieved, each with its own benefits and drawbacks. This technology is coming soon - almost certainly within 20 years, and perhaps less than a decade. When it arrives, it will come quickly. Molecular manufacturing can be built into a self-contained, tabletop factory that makes cheap products efficiently at molecular scale.
THE FUTURE OF NANOTECHNOLOGY

The time from the first assembler, to a flood of powerful and complex products may be less than a year. The potential benefits of such a technology are immense. Unfortunately, the risks are also immense.

Why focus on molecular manufacturing?

Every manufacturing method is a method for arranging atoms. Most methods arrange atoms crudely; even the finest commercial microchips are grossly irregular at the atomic scale, and much of today's nanotechnology faces the same limit. Chemistry and biologyhowever, make molecules defined by particular arrangements of atoms – always the same numbers, kinds, and linkages. Chemists use clever tricks that do not scale up well. Biologyhowever, uses a more powerful method: cells contain molecular machines that read genetic data to guide the assembly of large molecules (proteins) that serve as parts of molecular machines. Molecular manufacturing will likewise use stored data to guide construction work done by molecular machines, greatly extending abilities in nanotechnology.

The molecular assembler concept

The basic idea is simple: where chemists mix molecules in solution, allowing them to wander and bump together at random, molecular assemblers will instead position molecules, bringing them together to the specific location at the desired time. Letting molecules bump at random leads to unwanted reactions – a problem that grows worse as products get larger.

By holding and positioning molecules, assemblers will control how the molecules react, building up complex structures with atomically precise control. Picture an industrial robot arm standing next to an unfinished work piece. A conveyor belt supplies the arm with parts, each mounted on a handle. Step after step, the belt advances, the robot grips a fresh handle, plugs the attached part into the work piece, then puts the empty handle back on the belt. Eventually, the work piece is finished and another belt moves it away, shifting a new unfinished work piece into place. To picture a molecular assembler in a manufacturing system, imagine that all the parts are measured in nanometers, and that the transferred parts are just a few atoms, shifting from handle to work piece through a chemical reaction at a specific site. An assembler works as part of a larger system that prepares tools, puts them on the conveyor, and controls the robotic positioning mechanism. This will be a complex system that no one will build any time soon. Indeed, no one is even trying to build molecular assemblers today, because nanotechnology is still in its infancy. We can see a path to assemblers, just as the rocketry pioneers of the 1930s and 1940s could see a path to the Moon. But like those pioneers, we are not ready to attempt the final goal. They knew they must first launch many satellites, just as we must first build many molecular machines.
