The researchers from the University of Washington have manufactured a phone that instead of requiring batteries, works on a few microwatts of power obtained either from ambient radio signals or the light.
The technology which is stated in Proceedings of the Association for Computing Machinery on Interactive, Mobile, Wearable and Ubiquitous Technologies showed that in order to provide evidence that the prototype can receive and transmit speech and also communicate with a base station, the team also made Skype calls.
The co-author Shyam Gollakota expressed, “We’ve built what we believe is the first functioning cellphone that consumes almost zero power. To achieve the really, really low power consumption that you need to run a phone by harvesting energy from the environment, we had to fundamentally rethink how these devices are designed.”
The team comprising of scientists and engineers banished the step of transmuting the analog signals that transmit sound into digital data that is understandable by a phone. As an alternative, the new phone uses tiny vibrations in the microphone that happens when a person is talking or listening to a call.
According to Phys.org, “through an antenna, that motion is turned into changes in standard analog radio signals that are released by a cellular base station. For transmitting speech, the phone makes use of a microphone for encoding speech patterns in reflected signals and for receiving speech, the phone alters encoded radio signals to sound vibrations.
The phone was able to perform basic functions like transmitting speech and data and receiving user input via buttons. Also, through Skype, researchers were able to receive incoming calls, dial out and place callers on hold.
The normal Wi-Fi routers could commonly be used for making the calls, as the co-author Vamsi Talla explains, “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 cellphone coverage everywhere,” reports International Business Times.
Having a power budget of 3.5 microwatts, the battery-free phone could be operated on power from ambient radio signals transmitted by a base station up to 31 feet away. Whilst using power from ambient light with a tiny solar cell, the device could communicate from up to 50 feet away.
Furthermore, the team aims to enhance the operating range and to encrypt conversations. Also, they plan on streaming videos and adding virtual display feature through low-power E-ink sensors.