Medical implants such as pacemakers and gastric stimulators have improved our lives, but the batteries in these devices eventually run out and require surgery to replace them.

It raises a futuristic question: what if there was a way to avoid cutting a patient’s body open to replace a battery?

A team of Chinese scientists have come up with a possible method to pull that off by developing an implantable battery that uses oxygen already inside the human body to continuously power itself up.