Japanese device turns sweat into electricity without batteries promising wearable health sensors

Enzyme ink harvests power directly from perspiration

Japanese scientists say they’ve built a wearable that generates electricity from human sweat using special enzyme ink. The breakthrough could remove batteries and charging cables entirely, while still powering low-energy sensors. Once operating, the device can wirelessly transmit data—an approach that may reshape the design of future health monitoring gadgets by making them more sustainable and convenient.