Using Sound to Position Nanowires
Cable management can be a pain to get just right, but at least when routing the wires behind a desk or in your computer, you can see them. Positioning nanowires as needed is considerably more difficult, especially when the size of the nanowires drops below 50 nm. Researchers at Penn State however have found a way to precisely position nanowires into desired patterns using sound waves.
Sound waves are physical movements, and with proper tuning you can construct an interference pattern with voids in it, where there is no movement. This is what the researchers are taking advantage of by generating sound waves in a solution of nanowires. The nanowires are pushed to the voids and remain there as the solution evaporates around them. The patterned nanowires can then be transferred from the piezoelectric substrate they were on to an organic polymer substrate, and from there to any other substrate desired.
This ability to pattern nanowires with relative ease could be very useful for producing sensors, optoelectronics, and nanoscale circuitry. Potentially we could also see the nanowires transferred to living cells.
Source: Penn State