If you simplify your smartphone to the level of a simple communicator, eliminating the work with resource-intensive applications, then the most expensive task will be converting an analog signal into a digital one. That is, radio waves in letters, pictures and sounds in dynamics, so that the user can maintain a dialogue. But what if we abandon this process altogether?
There is no room for batteries in the prototype scheme of scientists from the University of Washington, this device does not consume energy at all. It is designed on the principle of the simplest radio station, where the radio signal from the antenna is directly converted into acoustic vibrations, the sound in the user's earphone. And vice versa, the speech of a person turns into a radio signal and goes to the subscriber, therefore work is possible only in "reception-transmission" cycles.
The highlight is that this prototype does not spend its energy on generating the outgoing signal, but uses the power of the reflected beam from the communication base station. Internal circuits still need 3.5 microwatts to work, which can be extracted from radio waves within a 9m radius or obtained through a solar panel. A grain of rice-sized photocell collects light from sources within a radius of 15 m.
At the output, we get a very weak, completely non-mobile and very infrastructure-dependent passive transceiver device. So far, this is an experimental option, but scientists are already seeing how cheap and useful emergency communication systems for Wi-Fi routers will be built on its basis. And for all other elements of the Internet of Things too - even the ability to simply ping each other without spending energy is expensive.
A major, fundamental disadvantage of the technology is that in the absence of a battery it is impossible to accumulate, store energy for performing large and long-term tasks. According to the Techcult, the threshold for passive production of energy from the surrounding space without harm to communications does not exceed 10 microwatts. But Washington is confident that it will be able to develop modules that will have enough of these crumbs of energy to perform a wide range of useful work in a pulsed mode.