This battery-free cellphone runs on light and radio waves

Who cares about an OLED and a notch when your phone can sip power from its surroundings, allowing you to make calls without ever having to charge your phone.

This wild cellphone is part of a Google Faculty Research program and received three U.S. National Science Foundation grants for total investment of about $2 million. For that money, the creator, Vamsi Talla, built a single-board cellphone that can make regular phone calls connect you to emergency services. The team is commercializing the product at Jeeva Wireless.

According to IEEE, this thing can even make Skype calls:

The phone receives power from sunlight or RF waves sent from a nearby base station, a fixed point of communication for customer cellular phones on a carrier network. With a technique called backscattering, the phone can make a voice call by modifying and reflecting the same waves back to the base station.

We also were able to make Skype voice calls, proving that the prototype—made of commercial, off-the-shelf components—can communicate with a base station and applications like Skype. The phone consumes only 3 microwatts of power—which is about 10,000 times less than what a current smartphone consumes.

Because this technology doesn’t require much in the way of changing cell towers Talla believes most cellphones could easily add this feature in the future. This means you could make a call even on a dead phone. Talla is also planning to add an e-ink display which means you could feasibly do very basic smartphone functions on your battery-less phone. The current model could cost as little as $1 to produce, which makes it excellent for developing countries.