At the University of Washington created a cell phone does not need to be recharged from the mains
Researchers from the University of Washington have developed cell phone, which receives energy required for operation from the environment. Using the energy of radio waves, the apparatus does not need to be recharged from the mains.
To make this possible, the developers had to find a way to radically reduce the power consumption of the device as to meet the needs of modern smartphones with the energy dissipated in the form of radio waves in the surrounding space, it is impossible.
According to project participants, they excluded the conversion between analog and digital signal form, which is energetically very costly. Instead, the device uses analog modulation. The prototype consumes only 3.5 mW, being able to transmit and receive voice signal and data corresponding to the pressed buttons.
For communication established a special base station. However, according to the researchers, the existing base station and a wireless access point too, can give the appropriate functionality. Communication range with the base station was about 10 m. If powering the device from a small solar battery (about the size of a grain of rice), the communication range is increased to 15 m.
Now researchers are working on crystal radio increase the distance of communication, and encryption to protect the communication channel. Also planned is the addition of E Ink screens and support second streaming video.
Source: CDR Info, University of Washington