Fingertips have thousands of sweat-producing glands, churning out anywhere from 100 to 1,000 times more sweat than other parts of the body. Researchers from the University of California, San Diego, have developed a way of harnessing this perspiration as an energy source to power wearable medical sensors. This innovation is a leap towards a future of practical, convenient, and accessible health monitoring technologies, empowering individuals to take control of their health and wellbeing effortlessly.
Researcher Lu Yin led a team of researchers that designed tiny biofuel cells capable of utilizing lactate—a chemical byproduct of cells generating energy in the absence of oxygen. An enzyme on the device breaks down lactate, creating a small electrical charge of around 20 to 40 microwatts. While these tiny amounts of harvested energy would not be sufficient to, say, charge your phone, they will be able to power small, wearable diagnostic technologies such as heart rate and glucose monitors. In addition, the innovation features small chips made of piezoelectric materials, which enables the generation of energy when the wearer presses on it.
The technology for converting sweat into electricity has been around for some time. However, previous iterations rely on more significant amounts of sweat to work. Yin and colleagues focused on the fingertips for this reason—they produce small but constant amounts of sweat that can be used as a power source even without having to endure an intense workout. According to the authors, this breakthrough demonstrates record-breaking energy return on investment compared to existing lactate biofuel cells.