The number of wearable technologies that use sensors as medical tools to track a person’s well-being – is on the rise. All of them – need an electric charge or a battery source to operate, but a handful of researchers are trying to take batteries out of the equation. At the Texas A&M University in College Station, researchers are doing just that – looking at ways to use our own body heat to power all those sensors. Elizabeth Lee takes a look at the emerging new technology.