SemiSerious

A couple weeks ago I scratched rather shallowly into the topic of turning motion energy into useful electricity (check it out). I was impressed with the development of a technology that could convert power line frequency mechanical vibrations into about 40mW from a device fitting inside a one centimetre cube. This, I argued, would start to put wireless sensor networks on the map.

Once again through Technology Review, I have now discovered that someone has taken the miniaturization of the concept to a much smaller level. Technology Review recognized Xudong Wang with its TR35 award for young innovators. His energy conversion device is small enough for implant into the body to power biosensors. I have not been able to confirm the power density or typical dimensions, but one nanoamp was reported in Technology Review. The device produces its electrical current by converting ultrasonic frequencies. I cannot say for sure, but I assume the intention is to externally provide ulstrasonic energy to the biological entity containing the device.

So unlike the devices discussed previously in SemiSerious, Xudong’s invention may not be intended for harvesting wasted background energy from power line vibrations so unavoidable in our electrified world. On the other hand, optimization of the process used to produce the ZnO nanowire arrays appears to be leading to huge efficiency improvements. It isn’t a stretch to think that a small device on a white water river adventure in your blood stream or in your gut could provide enough power for many sensors and related circuits.

On a loosely related note, Georgia Tech appears to be upwardly mobile, at least in university rankings which puts them at number seven for US public institutions. In fact, they are tops in nanotech.

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