American researchers have created the world’s thinnest possible electrical wires by using tiny diamonds like lego blocks. The wires themselves are only three atoms wide, and the team believe they have a wide range of possible applications in industry.
The team from Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory have discovered that the smallest possible bits of diamond, known as diamondoids, can be used as nanostructure scaffolding. Their results are published in Nature Materials.
“What we have shown here is that we can make tiny, conductive wires of the smallest possible size that essentially assemble themselves,” said lead author Hao Yan, a Stanford postdoctoral researcher in a statement. “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 wire is made of sulfur and copper, a compound known as chalcogenide, and it’s a semiconductor. But the key to its success is the diamondoids, which are made of just 10 carbon atoms with an attached sulfur atom. Floating in a solution of sulfur and copper, and thanks to molecular forces, the nanodiamonds began assembling the wire without external input.
This animation shows how the diamondoids act as molecular building blocks and grow the nanowires. SLAC National Accelerator Laboratory
“Much like LEGO blocks, they only fit together in certain ways that are determined by their size and shape,” said Stanford graduate student Fei Hua Li, who played a critical role in synthesizing the tiny wires and figuring out how they grew. “The copper and sulfur 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.”
The team was able to construct wires with atom-by-atom precision, and the method is not exclusive to chalcogenides. The team successfully used diamondoids to build wires with cadmium, zinc, iron, and silver, which have already been employed in both the production and transfer of electricity.
“You can imagine weaving those into fabrics to generate energy,” added study co-author Professor Nicholas Melosh. “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.”
It's possible that nanowires could be weaved like fabric and eventually used to construct fabric that generates electricity, wearable electronics, and even superconductors.