Question: I was interested in hearing about your invention. Can you tell me more about your battery free smart watch.

Yannick Verbelen answered on 14 Mar 2023:

Thank you for your interest in the stuff I already invented previously! I’ve always been interested in wearable electronics, thinking of them as a way to augment human capabilities by adding communications and sensing. During my PhD research, I encountered energy harvesters, which are a type of electrical generators that can convert ambient energy into electrical energy. It turns out that a type of energy harvester exists that can convert heat (or, more precisely, a temperature difference between a hot and a cold side of the generator) into a tiny electric current. I wondered if I could use that tiny current to power small electronic devices, such as pacemakers. But, a pacemaker is embedded in the body, so keeping one side of it “cool” would be a problem. That’s how I ended with a smart watch as idea: it would absorb a tiny amount of heat from the body, and the aluminium case of the watch serves as the heat sink to sustain the temperature gradient. As long as the watch is being worn, the thermoelectric generator absorbs body heat and converts it into the electric power needed to drive the watch electronics. It’s the whole concept of the Matrix movie, just on a smaller scale: using human body heat as a power source. I think it’s pretty cool though!