The thinnest electrical wires you think you know aren’t found at the streets or at your home. In fact, it cannot be readily found anywhere because they are invisible to the naked eye – at only 3 atoms wide.
Researchers from Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory have successfully developed the thinnest possible electrical wires using diamondoids. These smallest possible bits of diamond were assembled to make a 3-atom wide electrical wire.
At nanoscale, the wire was made to fit together like molecular building blocks by grabbing various types of atoms and joining them together through the tip of a growing nanowire. Each block is made of diamondoid attached to sulfur and copper atoms, which are fit together in certain ways according to their size and shape pretty much like LEGO blocks.
An animation below made by the researchers at SLAC National Accelerator Laboratory best describes how the molecular building blocks just self-assemble.
The conductivity is produced by the copper and sulfur atoms – collectively known as chalcogenide – in the middle with the diamondoids forming an insulating outer shell.
Hao Yan, lead author of the paper and a Stanford postdoctoral researcher explains, “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,” he adds.
Co-author Nicholas Melosh, an associate professor at SLAC and Stanford and investigator with SIMES, the Stanford Institute for Materials and Energy Sciences at SLAC, reveals that this is not the only way to get materials to self-assemble. But he says this is the first one shown to make a nanowire with a solid, crystalline core that has good electronic properties that this is the first one shown to make a nanowire with a solid, crystalline core that has good electronic properties.
He further added that the atomic size of the material is critical in the configuration of the wires in terms of precision and control. Such provides “different, extraordinary properties compared to the same material made in bulk”.
Forming the thinnest wire involved the smallest of diamondoids, which are single cages that contain just 10 carbon atoms, attached with a sulfur atom to each. While floating in a solution, these sulfur atoms bond with copper ions, thereby creating the basic nanowire building block.
Because diamondoids are strongly attracted to each other –through the scientific phenomenon called van dew Waals forces – the building blocks clump together and grows through the tip.
Stanford graduate student Fei Hua Li elaborates, “Much like LEGO blocks, they only fit together in certain ways that are determined by their size and shape.
“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.”
New materials like cadmium, zinc, iron, and silver are now being looked into to replace copper and sulfur and make the same kind of nanowires and technique. Cages like carboranes instead of diamondoids are also being experimented.
Sources: Stanford | Science Alert
