Tech that turns sweat into power may make for greener gadgets. A new device uses perspiration to charge a supercapacitor and run a sensor.
One route to greener electronics may involve working up a good sweat. Engineers are designing energy-storage systems powered by perspiration. One uses the salty moisture to charge a supercapacitor (SU-per-ka-PASS-ih-tor). The energy it stores can later be used to light an LED or run some type of electronics.
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Like a battery, a supercapacitor stores energy. Researchers described their new model May 11 in Advanced Materials. Such sweat-powered devices could pave the way to wearable tech that is both safer and more sustainable.
Today’s wearable electronics include gadgets strapped to the body, such as watches and fitness trackers. But engineers are also designing electronics that are part of clothing or stuck right onto the skin. “Many times they are made of materials that are not sustainable or eco-friendly,” says Ravinder Dahiya. He’s an electronics engineer at the University of Glasgow in Scotland.
Batteries power most wearable devices today. Those batteries often contain harmful chemicals, such as acids. When it’s time to dispose of batteries, their chemicals can harm the environment. For safer tech, “why not then use something which is [a] body fluid?” Dahiya asks.
Sweat serves as the electrolyte, or charge-carrying solution, for the new device. “That’s kind of a new way of using sweat,” observes Mallika Bariya. A materials scientist, she works at the University of California, Berkeley and did not take part in the new research. Electrolytes are an “important component of these supercapacitors or even batteries,” she notes. They’re needed for these devices to provide power.
People often think about sweat as gross or unwanted. But sweat is interesting, she argues. It can tell you about someone’s health. Also, its chemical makeup can vary depending on what part of the body makes it. This new work “really shows that sweat isn’t a … useless, icky fluid,” she says. “It’s something we should think about more.”
