This device will now need you to press the switch between transfer mode and listening mode, nor is it a one-touch experience like normal phones. But in the future, this technology can integrate with standard mobile network infrastructure and WiFi routers.
'Our team has worked with battery-free equipment and low-energy communication for the past 5 years. This project uses some of the techniques we developed earlier, for example, a batteryless phone using a non-energy analog backscatter microphone developed in 2012. We then combined with the system. headphone analog and backscattering communication system ', said Vamsi Talla, a researcher in the project.
'I built 2 hardware versions of the prototype phone,' he said. The first version uses audio signal RF transmission through the telephone tower. The second one has 'small photodiode to get energy from natural light in office or apartment'. In situations where there is no RF, like you are in the forest or anywhere, the phone looks for ambient light to recharge.
The prototype of a battery-free phone includes many parts that you can easily buy: antennas, RF receivers and solar cells, microphones for listening and backscattering, and recording and transmitting voice , receivers, headphone jacks, digital communication systems, microcontrollers and some LED lights and capacitive touch buttons to help operate the device.
Don't expect to play games too soon because it won't be able to generate enough energy for that. 'Unless we redesign our components, it's difficult to get gaming power with RF waves,' Talla said.
Current phones consume 10,000 times more energy than what RF and natural light signals get. The team must reduce the energy required to transmit and receive voices to microwatt levels. 'The amount of energy obtained from RF signals depends on the distance between the phone and the telephone tower. Usually 1 to 100 microwatt from RF signals will be obtained. We redesigned the structure of the phone to reduce consumption by about 1,000 times so that it could continuously be recharged from very low energy levels. '
The next goal of the team is to improve the phone's operating area and ensure the conversation is encrypted. If you want to find out more, you can read the full research report that was released in July here http://dl.acm.org/citation.cfm?id=3090090 and read the website details of Battery Free Phone project here. http://batteryfreephone.cs.washington.edu/