Implants can be nourished by the body’s store of glucose, while batteries can be powered by air moisture.
Now, using an A5-sized device, a research team from Singapore has managed to generate electricity from a light breeze.
A long plate with a cube on its end is fixed to one side of a small base body.
The plate vibrates when wind speeds reach 7km/h and, swinging to the opposite side, presses two additional small plates together.
The ensuing friction effect creates up to 3 volts, which can generate 290 milliwatts.
Enough to power sensor devices used on buildings in order to monitor structural health. Or LED lights. Surplus energy is stored in a battery.