In an attempt to produce the thinnest electrical wire ever made, scientists have managed to construct a wire, measuring three atoms in width. For the experiment, they used tiny bits of diamonds called diamondoids attached to sulphur and copper atoms. This could be the first ever fabrics that can generate electricity simply through movement.
According to researcher Hao Yan from Stanford University, “What we have shown here is that we can make tiny, conductive wires of the smallest possible size that essentially assemble themselves.”
“The process is a simple, one-pot synthesis. You dump the ingredients together and you can get results in half an hour. It’s almost as if the diamondoids know where they want to go.”
The diamondoids, naturally found in petroleum fluids, are tiny structures resembling a cage. They are made of carbon and hydrogen and are strongly attracted to one another through van der Waals forces, which result in each diamonoid linking up with the next one in the chain.
When these cages each join a single copper and sulphur atom, the forces between the diamondoids form a constant, wire-like structure.
In the words of researcher Fei Hua Li, “Much like LEGO blocks, they only fit together in certain ways that are determined by their size and shape.”
“The copper and sulphur atoms of each building block wound up in the middle, forming the conductive core of the wire, and the bulkier diamondoids wound up on the outside, forming the insulating shell.”
This is not the first endeavor for scientists to develop nano-wires capable of conducting an electrical current. However, the three-atom-wide diamondoid chain is the thinnest wire ever produced.
“Other molecular self-assembly methods have been tried, yet balancing the delicate interplay between attractive and repulsive forces to get just the size you want has proven very difficult,” explained one of the team, Nicholas Melosh.
“Achieving a ‘solid core’ of a three-atom cross section is ideal. It’s small enough to exhibit unique functionality, yet it can tolerate single defects or strains since there is still a pathway for the electrons to flow.”
At present, the scientists are trying to replace copper and sulphur with new materials in order to determine what other kinds of nano-wires can be created with the same technique.
So far, cadmium, zinc, iron, and silver have been examined, and other forms of cages, including carboranes, have been used instead of diamondoids.
The experiment results show that different kind of conductivity is obtained depending on what molecules are used at the wire’s core. Such tiny wires could see a wide range of applications in the near future. Some of these include the use for electrical devices, or superconducting materials that conduct electricity without any loss due to their intricately formed molecular structure.
Another application includes piezoelectric energy devices, which generate electricity from motion.
“You can imagine weaving those into fabrics to generate energy,” Melosh says in a press release.
“This method gives us a versatile toolkit where we can tinker with a number of ingredients and experimental conditions to create new materials with finely tuned electronic properties and interesting physics.”
The findings are published in Nature Materials.