June 24, 2006

NEMS scale conversion of movement versus smaller scale

As noted at Foresight, Nanogenerators have been made that produce current by bending and then releasing zinc oxide nanowires – which are both piezoelectric and semiconducting. The researchers grew the nanowire arrays using a standard vapor-liquid-solid process in a small tube furnace. First, gold nanoparticles were deposited onto a sapphire substrate placed in one end of the furnace. An argon carrier gas was then flowed into the furnace as zinc oxide powder was heated. The nanowires grew beneath the gold nanoparticles, which serve as catalysts.

The resulting arrays contained vertically-aligned nanowires that ranged from 200 to 500 nanometers in length and 20 to 40 nanometers in diameter. The wires grew approximately 100 nanometers apart, as determined by the placement of the gold nanoparticles.

Wang estimates that they can convert as much as 30 percent of the input mechanical energy into electrical energy for a single cycle of vibration. That could allow a nanowire array just 10 microns square to power a single nanoscale device – if all the power generated by the nanowire array can be successfully collected.

Here is something that would be closer to small nanoscale translation of movement into power.

Proteins such as Prestin in the inner ear, or mechanosensitive ion channels found in almost all living organisms, translate nanometer movements into milli-volts of electricity.

This is part of the most recent batch of Nasa Institute for Advanced Concepts funded studies.

Bio-electric space exploration study by Matthew Silver. He is working on developing ideas at the intersection of synthetic biology, space systems design, space operations, and electrical engineering.

Molecular manufacturing should find ways to leverage and integrate with the DNA/RNA/protein nanotechnology and synthetic biology work.