Computer Science & Engineering Department of University of Washington researchers invented a mobile phone that doesn’t require batteries. Now you can make calls and receive with only a few microwatts. This prototype has a tiny photodiode, collects light while a radio frequency harvester makes it possible to use energy sent out wirelessly from a homemade cell tower, called a base station. This battery free device prototype is built using commercial-off-the-shelf components on a printed circuit board. It can operate on power that is harvested from RF signals transmitted by a basestation 31 feet (9.4 m) away.
The device can sense speech, actuate the earphones, and switch between uplink and downlink communications, all in real time.
The researchers even made a Skype call using the prototype. This is a major break through towards battery free cell phone.
Joshua R. Smith