Moving robots typically demand a lot of energy, which requires a battery that only has a limited lifetime.

Researchers at the University of Washington (UW) have created MilliMobile, which is equipped with a solar panel-like energy harvester and four wheels.

The robot is about the size of a penny, weighs as much as a raisin and can move roughly the length of a bus (approximately 10 metres) in an hour, even on a cloudy day.

Image credit: Mark Stone University Of Washington

The robot can also drive on surfaces such as concrete or packed soil and carry nearly three times its own weight in equipment, such as a camera or sensors. It uses a light sensor to move automatically toward light sources so it can run indefinitely on harvested power.

“We took inspiration from ‘intermittent computing,’ which...