This is scientific American 60 second science. I'm Christopher in Tagata.

A dying battery is a huge annoyance for cell phone users, but for engineers, it's inspiration.

Can we design a smartphone which can make a phone call and you can have a conversation without the need for any kind of a battery?

Sham Golakota is a computer scientist at the University of Washington, and he and his team have indeed designed

a battery-free phone.

It looks like a circuit board with touch-responsive numeric buttons, and it runs on just a few micro watts of power, which at Harvard. responsive numeric The team achieves a battery-free energy efficient design by ditching two of the power hungry features of modern cell phones.

One, the test unit skips digital to analog conversion.

And two, it does not generate its own wireless signals to make calls.

Instead, in receiving mode, it absorbs incoming radio waves from the base station

and converts them directly into vibrations of its speaker.

In sending mode, it uses the vibrations of its on-board microphone

to change the way radio waves are reflected back to the base station.

And it worked to make a Skype call.

Hello?

Hello from a battery-free cell phone.

The findings appear in the proceedings of the Association for Computing Machinery

on interactive, mobile, wearable, and ubiquitous technologies.

The demo device does have limitations.

It can only stray 50 feet from the base station,

and the voice quality is pretty low-fi.

And you can't check Facebook either.

Yet. Oh, if you're going to get that. I mean, this is again a first step. Think of it as like,

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