Paul van Gerven
11 March 2020

Eindhoven University of Technology researcher Daniel Vakulov has developed a microgenerator that can deliver 30 microwatts of electrical power from a temperature differential of three degrees Celsius. That may not seem like much, but since hundreds of these microgenerators fit on a fingernail, together they could power an IoT device, such as a wall or ceiling-mounted sensor. A three degree Celsius temperature difference is very common on these surfaces.

The microgenerator uses nanowires made of indium antimonide (InSb). These were suspected to be too thin to transport heat effectively, but thick enough to conduct electricity. Through the thermoelectric effect, this should mean that any heat energy added to the nanomaterial ‘needs’ to be lost as an electric current. After confirming this in fact happens, the researcher of Russian origin built an actual generator.

Vakulov defends his PhD thesis entitled “Nanowires for thermoelectric energy conversion” on 10 March.

Nanowire nanogenerator
The nanogenerator looks like a piece of sticky tape with black squares encased in the plastic. Each of these ‘dots’, no wider than half a millimeter, contains about a million nanowires measuring about four micrometers in length. Credit: Daniel Vakulov