Two Indian scientists at University of Washington, along with their team have made a battery-free mobile.
Can we dream of having a battery-free cell phone, which operates on consuming only a few microwatts of power? Such a creation would allow mobile phones to communicate without the need of batteries. They could derive minuscule power from cheap and lightweight energy sources. These include radio signals and photodiodes instead of bulky and costly solar cells. Mobile phones need to perform multiple basic operations. They are capable of sensing speech at the device, transmitting it to the base station, receiving speech information from the base station, and finally actuating the speaker/earphones. Can it perform all these operations in real time using only a few microwatts of power?
The researchers of University of Washington have invented the cell phone that does not require any batteries — a great jump forward in moving beyond chargers, cords, and dying phones. The phone, on the other end, yields the few microwatts of power it requires from either ambient radio signals or light.
The team also made Skype calls using its battery-free phone, demonstrating that the prototype made of commercial, off-the-shelf components can receive and transmit speech and communicate with a base station.
A bit About the Battery-Free Creators
This research was led by Vamsi Talla, an alumnus of Delhi Public School, Panipat refinery and a B.Tech from IIT Guwahati who went onto do his MS and Ph.D. in Electrical Engineering at Washington State University in the US. Talla’s co-author and co-researcher is Shyam Gollakota, the alumnus of IIT Madras, who did his MS and D at MIT, the US. He is the associate professor in the Department of Computer Science and Engineering at the University of Washington where he leads the Networks and Mobile Systems Lab. With Talla, he is a co-founder of Jeeva Wireless.
How Does This Work?
They eliminated the most power-hungry step in most mobile phones by modifying analog signals that convey sound into digital data. This is something that a phone can understand. This process consumes so much energy that it was almost impossible to design a phone that could rely on medium power sources—only until now. Instead, this battery-free cell phone works on the tiny vibrations in a phone’s microphone or speaker. These vibrations occur when a person is talking into a phone or listening to a call. An antenna connected to the components converts the motion into changes in a standard analog radio signal, which are cast out by a cellular base station.
To broadcast speech, the mobile uses vibrations from the technology’s microphone to encode speech patterns in the reflected signals. To receive this speech, it again converts encoded radio signals into sound vibrations that are picked up by the phone’s speaker.
The team designed a custom-base station to send and receive the radio signals. But in real-life circumstances, the technology could be included into a standard cellular network infrastructure or Wi-Fi routers.
Having proved that you can get away with this tiny power, what’s next? The research team now plans to perk up the battery-free phone’s operating range. The scientists are also working on encrypting conversations to make them secure.