The world's smallest electric wire

Scientists at Stanford and the SLAC National Accelerator Laboratory have created the world's smallest electrical wire by using the self-organizational abilities diamondoids, the smallest bits of diamonds. The wires measure just three atoms wide.

The new assembly strategy offers impressive precision and control and requires no hands-on intervention.

"What we have shown here is that we can make tiny, conductive wires of the smallest possible size that essentially assemble themselves," Hao Yan, a Stanford postdoctoral researcher, said in a news release. 

"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 construction of the world's smallest electric wire

Diamondoids serve as both assembly toolset and insulator, surrounding the semiconductor core made of chalcogenide, a unique copper and sulfur combination.

Diamondoids are extracted from petroleum fluids and sorted by size. Scientists selected diamondoids made up of 10 carbon atoms and attached a sulfur atom to each. The diamond bits were then placed in a solution where each sulfur atom were able to bond with a single copper ion.

Once bonded, the diamondoids were drawn to each other by a force known as van der Waals attraction. The bit naturally fit together in a way that creates a tiny wire of sulfur and copper ions.

"Much like LEGO blocks, they only fit together in certain ways that are determined by their size and shape," explained Stanford grad student Fei Hua Li. "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 scientists used their diamondoid assembly technique to build one-dimensional wires composed of cadmium, zinc, iron and silver. The wires could be used to improve optoelectronics, light-emitting diodes, solar cells and other technologies.

"You can imagine weaving those into fabrics to generate energy," said Stanford 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."