 Scientist at Lanzhou University in China published a paper in the journal Science Advances describing a prototype for an implantable wireless energy device. The biodegradable device can receive and store energy to power bioelectric systems, things like sensors for monitoring your health or small devices that deliver drugs in particular amounts. The new device uses a magnesium coil to charge when a power transmitter is placed on the skin above the implant. And then the power is stored in a module made of zinc supercapacitors. The amounts of zinc and magnesium are below the daily intake recommendations for people. So when they get reabsorbed in the body, they're just used as nutrients. Tests and rats worked for up to 10 days, and the device fully dissolved into their bodies within two months.