New Body-Heat Tech Could Eliminate Smartwatch Chargers

A recent breakthrough in battery technology suggests that body heat could one day replace traditional chargers for smartwatches and other wearables. Researchers from a university in South Korea, led by Professor Jang Sung-yeon, have developed a new ionic thermoelectric material capable of generating energy from the temperature difference between human skin and the surrounding environment. This material, produced in the form of a thin, flexible film, shows strong potential for integration into devices worn directly on the body.

While thermoelectric materials are not entirely new, the performance of this specific film marks a significant improvement. According to the research team, the material can generate 1.03 volts for every 1°C difference in temperature. During testing, the film successfully powered an LED lamp for two consecutive months, maintaining stable performance for 95% of the experiment. These results highlight the feasibility of a wearable power source that continuously generates energy without needing traditional charging methods.

If integrated into consumer products, this technology could profoundly impact the smartwatch and wearable market. Since the material is thin and adaptable to curved surfaces, it can be incorporated into various devices, such as smartwatches, smart rings, and fitness bands, without changing their design or comfort. Its flexibility makes it especially suitable for wearables that maintain constant contact with the skin.

Battery life is a long-standing issue for smartwatch users. Depending on the model, devices may last anywhere from 24–48 hours to roughly two weeks, but heavy usage—such as GPS tracking, Always-On Display, or multiple active sensors—quickly drains the battery. Users often need to recharge their device daily or every few days, which can be inconvenient for devices meant to stay on the wrist around the clock.

This new thermoelectric solution could potentially eliminate the need for traditional charging altogether. By converting the natural temperature difference between the body and the environment into continuous energy, the wearable would recharge itself throughout the day. In practical terms, this could lead to smartwatches that never need to be plugged in, ensuring uninterrupted functionality regardless of usage level.

While the technology is still in the research phase, its promising results indicate a future in which wearables maintain full autonomy, improving convenience and extending device lifespan without relying on chargers, cables, or charging pads.

Filed in Gadgets. Read more about Science and Smartwatches.