What do you think a major turn-out would be in the field innovation as far as smart-devices are concerned? Yes, batter-life. Who does want to spend precious time of their days hanging with their chargers?  But as rumor has it, and we can’t quit looking towards future, in a distant one there are methods being worked on to provide power to your wearable by utilizing the heat constantly getting emitted from the wrist.
Body heat charging tech
Developed by the Korean Advance Institute of Science and Technology (KAIST), this technique converts body-temperature into electricity through a quite thinner (~500 μm) thermoelectric power-generator, imposed on a transparent fabric. Apart of that it is quite light, elastic, bendy, and comes with a self-sustainable arrangement “without top and bottom substrates”. KAIST pertains to claim that its thermoelectric generator has ten times greater energy output density alike generators of that kind.
“For our case, the glass fabric itself serves as the upper and lower substrates of a TE generator, keeping the inorganic TE materials in between,” as declared by an electrical engineering professor, Byung Jin Cho, at KAIST. He further added, ”This is quite a revolutionary approach to design a generator. In doing so, we were able to significantly reduce the weight of our generator, which is an essential element for wearable electronics.”
Till so far, the usual available thermoelectric generators  have been quite bulky and not appropriate for wearables. Still, as KAIST’s innovation lets drastically smaller devices to get charged by body-temperature. The researchers at KAIST add the fact that their technological advancement in this peculiar sector could be used in automobiles, factories, aircrafts, and vessels, where the wasted thermal energy can find its way in making it a useful one.