New Device Powers Wearable Sensors Through Human Motion

The advent of inexpensive wearable sensors that can monitor heart rate and body temperature, as well as levels of blood sugar and metabolic byproducts, has allowed researchers and health professionals to monitor human health in ways never before possible. But like all electronic devices, these wearable sensors need a source of power. Batteries are an option, but are not necessarily ideal because they can be bulky, heavy, and run out of charge. Caltech's Wei Gao , assistant professor of medical engineering in the Andrew and Peggy Cherng Department of Medical Engineering, has been developing these sensors as well as novel approaches to power them using the human body itself. Previously, he created a sensor that could monitor health indicators in human sweat that is powered by sweat itself. Now, Gao has developed a new way to power wireless wearable sensors: He harvests kinetic energy that is produced by a person as they move around. This energy harvesting is done with a thin sandwich of materials (Teflon, copper, and polyimide) that are attached to the person's skin.