Recharge an electronic device with your body

A group of Korean researchers of KAIST (Korea Advanced Institute of Science & Technology) has developed a system that can charge wearable devices by the warm of the human body.
What you see in the image could simply be integrated in wearable devices such as smartwatch, fitness bracelets and so on allowing the same to recharge, to the point of being completely autonomous, with this thermoelectric generator that takes the heat from our body, transforming it into electricity. This approach is not new, but the merit of these researchers is that they used inorganic materials that have allowed to maintain a reduced weight and size even managing to print circuits on an extremely flexible support and therefore easily wearable, in glass fiber. This will then allow not only to integrate perfectly within the devices, but also to be easily wearable.