Currently, smartwatches, fitness trackers, and even medical monitors rely on bulky batteries that require frequent recharging. But what if these gadgets could run indefinitely without batteries, by simply drawing power from the warmth of your skin? That scenario may become a reality with a team of researchers at Peking University having unveiled a revolutionary rubber-like material that converts body heat into electricity.
The breakthrough, published in the journal, Nature, focuses on scientists having developed a stretchable rubber-like material that converts body heat into electricity for wearable tech. The thermoelectric elastomer is a stretchable, conductive polymer that generates power by harnessing the natural temperature difference between your body (around 37°C) and the cooler surrounding air. Unlike rigid thermoelectric materials used in space probes or industrial applications, this new rubber can stretch up to 150% of its original length and recover its shape, making it ideal for skin-tight wearables. Even more impressive, it can withstand extreme strain of over 850% without losing functionality.
The science behind this innovation lies in thermoelectricity, the process where a temperature gradient between two points creates an electrical current. Your body is a constant heat source, maintaining a steady 37°C, while the air around you fluctuates between 20°C and 30°C.
Peking University team’s material exploits this difference, allowing electrons to flow from the warmer side (your skin) to the cooler side (the air), generating usable electricity.
To enhance performance, the scientists incorporated a doping agent called N-DMBI, which significantly boosts conductivity. The result? A material that not only stretches like rubber but also efficiently converts heat into power, something previous thermoelectric materials struggled to achieve.
“We are the first in the world to propose the concept of thermoelectric rubber,” said Lei Ting, a materials scientist at Peking University, in an interview with the South China Morning Post. “Such thermal devices are comfortable to wear and efficiently convert the body’s heat energy into electrical energy with less heat loss.”
The implications of this technology are vast. This new material could eliminate that need entirely, enabling self-powered devices that run indefinitely as long as they remain in contact with skin.
But the applications don’t stop at consumer electronics. The researchers envision medical sensors that could be worn as patches, continuously monitoring patients without the hassle of battery replacements. For example, cardiovascular patients who currently wear cumbersome holter monitors for a week could instead use lightweight, flexible sensors powered by their own body heat.
Lei Ting also suggested broader uses, such as integrating the material into clothing. Imagine a jacket that charges your phone while you walk or a shirt that regulates your body temperature by drawing heat outward. In emergency scenarios, devices could even scavenge heat from a fire to power remote communications gear.