Be Ready To Call From First Battery Free Phone Part 2
In the previous part of this series, we told you how a team of scientists and researchers invented the phone that operated without battery. Now we will explore how this battery-free phone actually functions.
How does battery-free phone work?
The process of converting of analog signals that would convey sound into digital data consumes a huge amount of power. Considering that, it has been impossible to design a phone that could rely on ambient power sources.
However, things are appearing different in the case of the battery-free phone. This phone takes advantage of tiny vibrations in the microphone or speaker of the phone. These vibrations occur when a phone call is underway. Following are the steps of procedure:
- Conversion: An antenna connected to the components mentioned converts that motion into changes in a standard analog radio signal that are emitted by a cellular base station. This process encodes speech patterns in reflected radio signals in a way that uses minimal power (or almost no power).
- Transmission: To transmit speech, this phone uses vibrations from the microphone of the device in order to encode speech patterns in the reflected signals. To receive speech, encoded radio signals are converted into sound vibrations that are picked up by phone’s speaker. In the prototype device, the user is supposed to press a button to switch between these two “transmitting” and “listening” modes.
A custom base station designed by the team transmits and receives the radio signals. However, as of now, this technology has some limitations. It can be integrated into Wi-Fi routers that are commonly used to make calls.Integration into standard cellular network infrastructure is also possible.
VamsiTalla, the co-author of this technology a former electrical engineering doctoral student and Allen School research associate, said:
“You could imagine in the future that all cell towers or Wi-Fi routers could come with our base station technology embedded in it. And if every house has a Wi-Fi router in it, you could get battery-free cell phone coverage everywhere.”
Although battery-free phone still requires a small amount of energy to perform some operations, the power budget of the prototype is 3.5 microwatts.
Other qualities of this phone:
Many other battery-free technologies, relying on ambient energy sources are surrounding temperature sensors. Once Temperature sensors or an accelerometer that can conserve power with intermittent operations, take a reading, they go to into “sleep” mode for a minute or two. While in sleep mode, they harvest enough energy to perform the next task. A phone call requires the device to operate continuously for as long as the telephonic conversation lasts.
Co-author Bryce Kellogg, a UW electrical engineering doctoral student, said:
“You can’t say hello and wait for a minute for the phone to go to sleep and harvest enough power to keep transmitting. That’s been the biggest challenge — the amount of power you can actually gather from ambient radio or light is on the order of 1 or 10 microwatts. So real-time phone operations have been really hard to achieve without developing an entirely new approach to transmitting and receiving speech.”
Future plans for battery-free phone:
The research team has following future plans for the battery-free phone:
- Improve the battery-free phone’s operating range.
- Encrypting conversations to make them secure.
- Video-streaming over a battery-free cell phone.
- Using low-power E-ink screens, add visual display feature to the phone.
Did you find the functioning of this battery-free phone intriguing? Share with us by posting your comments.
Visit us on LinkedIn and join us for discussions.