Pacemakers have a problem – and that’s not something you want to hear about a medical device which literally helps a person’s heart beat at a normal pace. The problem, simply put, is that they are powered by bulky batteries, which have to be surgically replaced at regular intervals due to their short lifespans. Fortunately, researchers from China and the US may have come up with a solution. They have developed an alternative battery-free pacemaker that can generate power from the kinetic energy of heartbeats. While not yet ready to be implemented into humans, it was trialed successfully in pigs. The results are exciting because the pig hearts used in the study are approximately the same size as human hearts. What’s more, the self-powering tech isn’t just promising for cardiac pacemakers, but could also be used for alternatives to other battery-powered implant medical devices, like neural or muscle stimulators.