One of the fundamental concepts of physics is that energy can be converted from one form to another. This is interesting, because it means that energy typically utilized by biological organisms, like humans, can be converted into other forms of energy useful for technology. The average human, for example, runs on around 100 watts. But like any other system, our bodies waste quite a lot of energy, because perfect efficiency is impossible. Like your car, your body’s inefficiency is mostly output as waste heat. This small wearable device harvests that waste heat and converts it into usable electricity
It is fairly common for machines to have some way of collecting wasted energy. For instance, many electric cars have a feature called regenerative braking. That uses the electric motors as generators to collect the kinetic energy from your car’s momentum as you slow down. But we rarely utilize the wasted energy from our own bodies. The only common devices that currently do so are self-winding watches, which rely on your movement. This wearable device, built by researchers from the University of Colorado Boulder, works in a similar way to harvest the heat given off by your body through your skin. The key component of this device is a thermoelectric generator (TEG) that produces electricity when there is a temperature differential, such as the difference between your skin temperature and the ambient air temperature..
Thermoelectric generators are commonly used for industrial applications, such as in power plants where they’re used to collect waste heat in order to improve the plant’s overall efficiency. This device works in exactly the same way, just on a smaller scale. Small TEGs are placed on flexible, wearable patches that can be applied to your skin. The size of those patches can vary to fit different parts of the body. They aren’t capable of producing a huge amount of electricity, but a small patch is enough to power small devices. It could potentially power a wristwatch, fitness tracker, medical devices like insulin monitors, and more. Technology like this is becoming increasingly sought after as wearable devices become more common. The team is currently working on making this technology as affordable and reliable as possible, and they believe that it could end up in consumer devices in as little as five years.