In the Victorian era, novel electrical devices promised to cure just about anything from anxiety and migraines to heart palpitations and diarrhea (not to mention various sexual complaints). Fortunately, scientific research has resulted in more effective and reliable uses of electricity in health tech devices, such as helping to manage pain or improve sleep.

A new development uses electricity to help broken bones mend. It has been known for some time than a current can help speed up bone healing, but this requires surgery to implant electrodes, and then another procedure to remove them once the healing is complete. A research team at the University of Wisconsin-Madison has come up with a novel solution: an implant that accelerates healing with electricity that then is absorbed by the patient’s body once the bone has healed.

At this point, you might well be asking, “Okay, but where does the electricity come from to power the implant?” Great question! As it turns out, bone is a piezoelectric material, which means that it produces small electrical currents when placed under strain. This electricity is part of what causes bones to heal naturally, and explains why adding electrical stimulation can speed the process. The implant is designed with a similar idea in mind; it generates its own power. Using triboelectric materials (producing what used to be called “static electricity”), the researchers created a thin film device that generates electricity from tiny movements.

The materials are not just biocompatible; they can biodegrade in time and be completely reabsorbed by the body. The current implant can generate stimulations of about 4 volts and last for more than six weeks. By tweaking the material’s properties, the team can control how long the device will survive in the body, from weeks to months. The team is looking into ways to scale this device to be practical for human injuries, including using changes in blood pressure and other movements as sources of energy to harvest.