Batter-free phone

A group of scientists from the University of Washington (UW) has created the first ever mobile phone that doesn't need a battery to power itself when making or receiving phone calls.

The main catch behind this creation is that the phone draws power from ambient radio signals and sunlight to power the circuitry needed to make or receive calls.

Currently, the device is just a phone, and you don't have a screen and anything else you can find in modern smartphones.

Phone only needs 3.5 microwatts of power

For the time being, researchers focused only on creating new technologies that can handle phone call operations but with lesser power than existing systems.

They succeeded by creating a system that only needs 3.5 microwatts of power to make or receive calls. The downside is that users need to be up to 50 feet close to a mobile base station to receive and amplify the phone call's signal.

Researchers plan to continue developing the ambient energy harvesting system so to improve power supply and support phone calls when the user is much farther away from a telco's base station.

As researchers find new ways to gather energy from the surrounding ambient, they also plan to add a visual display in the form of low-power E-ink screens and add support for encrypted conversations and video streams.

Phone is actually more of a walkie-talkie

Before all of the above, researchers plan to fix the phone's biggest drawback, which is a button that users need to press to switch between sending and receiving mode. Basically, the device is currently a walkie-talkie, as it requires users to press a button to switch between these two modes.

Nonetheless, researchers say that it's not a major technical hurdle to create a system that detects when the user is talking or not and make the switch between these two modes automatically.

UW researchers said they built their phone using off-the-shelf components, and also made a Skype call from their phone, not just a normal call.

The new ambient power harvesting technology and the revamped and energy-optimized phone calling mechanism is detailed in a research paper published this month called Battery-Free Cellphone.

Image credit: University of Washington