Researchers from the University of Washington have invented a cellphone that doesn’t require a battery to run.

Moving beyond batteries and cords, this invention is a significant attempt by the researchers. The phone produces the power it requires from either the ambient radio signals or light. To demonstrate the working of their phone, they made Skype calls using it. The commercial prototype of the phone has components to aid speech transmission. On July 1, this invention was published in detail in the paper in Proceedings of the Association for Computing Machinery on Interactive, Mobile, Wearable and Ubiquitous Technologies.

The conversion of analog signals into digital data that is understandable by the phone is the most power consuming process. So it becomes impossible to make use of ambient power sources. But the team decided to make use of the tiny vibrations that get created in the microphone or the speaker of the hone while a user talking on a phone or listening. The zero power process implemented by them encodes the speech patterns into reflected radio signals. While transmission, it makes use of the microphone’s vibrations to encode. For the reception, these encoded radio signals are decoded to sound vibrations that are caught by the phone’s speaker.

National Science Foundation and Google Faculty Research Awards funded the research work.