Cellphone without battery may soon become reality

Scientists of University of Washington in US have developed a battery-less cellphone which consumes almost zero power and runs by harvesting energy from ambient radio signals or light. But it uses a custom base station to send and receive the data.

To make a call, The cellphone uses vibrations from the device's microphone to encode speech patterns in the reflected signals and To receive a call, it converts encoded radio signals into sound vibrations.

The researchers made a Prototype which can perform basic tasks transmitting speech and data and receiving user input via buttons.