This is a phone that can make calls without batteries

If it becomes a reality, the application of new technology into practice is almost unlimited. But to get there, the research team at Washington University has a long way to go to commercialize the product.

"Hello, hello, I'm calling from a batteryless phone" is the message Vamsi Talla transmitted from inside a very busy laboratory at the University of Washington (Seattle, USA). And they heard Talla's greeting coming from a nearby Android phone. This is a revolution, because the cell phone Talla uses to make calls above without batteries.

According to Wired, the prototype of the phone (battery-free) below is the best result of Talla's year-long study, currently a research associate at Joshua Smith's laboratory (researcher). Research in computer science and electrical engineering at Washington University). "If you have to choose a device that doesn't use a battery, what would you choose?" Smith asked and shared: " Mobile phones are one of the most useful things today. Imagine how great it would be if your phone ran out of battery but you could still send messages and call electricity".

The new vision makes us think about how mobile phones work today. Thus, to be able to operate without batteries, the phone will get some energy from the surrounding environment.

Ambient light can turn into electric current using solar panels or semiconductor photodiode. Radio frequencies on TV and Wi-Fi waves can turn into energy thanks to antennas. A hybrid system using both of these technologies can generate energy sources of several tens of μW (micro Watt). The problem is that a traditional mobile phone when making a call uses a much larger source of energy, about 800 mW (Mili Watt).

The prototype of the phone can make calls without batteries.

The first thing the research team needs to solve is communication. Smith's lab developed a technique called "backscatter" , which allows a device to communicate by reflecting radio waves to it, like a field. Combine an injured hiker, send an emergency signal with a mirror and sunshine. Smith has also developed a solution called Jeeva Wireless and commercialized the technology that he calls "passive Wi-Fi" - using digital "back-scattered" techniques for devices that use Wi-Fi. Very low power Fi. However, even "passive Wi-Fi" with low energy consumption does not meet the demand for the mobile phone his group is pursuing.

"Converting human voices from analog (analog) signals to digital (digital) signals consumes a lot of power , " Talla said. "If you can communicate using analog technology, it will really be effective in energy use." So even though cell phones use digital signals to dial, the "backscatter" process for callback uses analog signals.

While developing the "Reverse Dispersion" technique using analog signals, Smith realized that he was reinventing the spy technology used during the Cold War. In 1945, the Soviet Union gave the US Ambassador to Moscow a gift of Great Seal from the United States. Inside it is a bug that hears, activates with radio waves at the correct frequency, as well as operates with the energy of this radio wave.

Smith said: "My father was a spy in the Cold War, so I heard stories about the" Great Seal "when I was young," and he shared: "I wonder if software can be used. to control the activity of "Backward Dispersing" using analog signals, turning curiosity into seemingly supreme things (only those who have read about intelligence stories know) into things can be used ".

Like the eavesdropping bug used in the war, some of the main components of the research phone are located far away to save energy. A base station located nearby has a circuit system to convert and connect to a digital mobile network, currently via Skype. The prototype prototype uses unlicensed frequencies, limited to low-energy transmissions. And because the phone collects energy based on the received signal, currently, the base station is only about 15 meters away from the phone.

To commercialize this phone, it is necessary to create a switching system inside the Wi-Fi router (at home or traditional broadcast base). Talla said: "The traditional transceiver station has a hundred times the power, which can increase the distance (between the phone and the base station) up to 1 km".

There is still a long way to go before that happens. The test phone has only a few basic touch keys and its only display "screen" is a tiny red LED that signals when the key is pressed. A larger touch screen will need about 400mW - which is about 100,000 times the power of the Talla phone currently in hand. Most importantly, the actual call is still quite difficult. You have to press a button to switch between listening and speaking in the style of calling radios, and making calls through static clouds is impossible.

Talla promises better call quality and will equip the next generation E-Ink screen , which can be added to a selfie camera. Smith said the team bought components that make the prototype of the phone from the outside but even cheaper than regular phones, if built on an industrial scale, it would be cheaper. . And the best thing, you will never have to worry about forgetting your charger at home again!