Researchers at Nanyang University of Technology in Singapore created a sweat-powered flexible battery. The device could provide a new way to energize medical portable equipment, some of which already use sweat to detect or control disease. The stretch device incorporates silver flakes that come together and generate a small electric current in the presence of sweat.
Medical wearables are increasingly ubiquitous. The ability to control vital signs or disease progression through such unobtrusive and convenient technology has obvious advantages. However, in the interests of the environment, moving away from traditional battery technologies would be advantageous, and what could be better than allowing the body to power your portable device?
“Conventional batteries are cheaper and more common than ever, but they are often made from materials that are unsustainable and harmful to the environment,” Lyu Jian, a researcher involved in the study, said in a press release. “They are also potentially harmful in portable devices, where a broken battery could spill toxic liquids on human skin. Our device could provide a real opportunity to completely remove these toxic materials.”
The new battery uses sweat as a power source. Sweat is rich in chloride ions and is the property that exploits the battery. It consists of a stretchy fabric on which the researchers deposited ink containing silver flakes, to act as electrodes. The acidity and chloride ions of sweat cause the flakes to clump together, causing an electrical charge. Because it can store absorbed sweat for long periods of time, the battery can generate energy even when someone is not exercising and is actively sweating.
“Our technology heralds a previously unattainable milestone in the design of portable devices,” said Lee Pooi See, another developer of the new battery. “Taking advantage of a ubiquitous product, perspiration, we could be looking for a more environmentally friendly way to power portable devices that do not depend on conventional batteries. It is an almost guaranteed source of energy produced by our bodies. We hope that the battery will be able to power all kinds of portable devices.
So far, the team has tested the battery on some volunteers. A volunteer rode a bicycle for 30 minutes and during that time the battery successfully powered a temperature sensor that communicated with a smartphone via Bluetooth.
“Our device could be more durable than current technology, as we demonstrated that it could withstand the stress of a user’s daily activities and repeated exposure to stress or sweat,” Lee Pooi See said. “The small size of our battery also solves two problems in portable technology: traditional button batteries are a problem to achieve a stylish and attractive aesthetic for consumers, while thinner batteries reduce the capacity of the article to load enough to last all day “.
Watch a video about the battery:
Study the magazine Scientific advances: Printable elastomeric electrodes with improved conductivity by sweat for the portable industry