Researchers develop a cell phone that needs no battery

Smartphones these days are showcasing the rapid progress in the world of technology. What was once a boxy plastic shell with countless keys has turned into an all-glass slab with borderless display and DSLR-rivalling camera. While various parameters like displays and cameras have gained incremental leaps, one area still hasn’t seen any considerable progress – their power source. To compensate the increasingly powerful specifications, manufacturers are still relying on a dangerous combo of lithium and ion, a point proved by the infamous Samsung Galaxy Note 7. However, scientists have come up with a way to eliminate the battery from the smartphone, completely.

A group of eggheads from the Paul G.Allen School of Computer Science & Engineering have developed a new cell phone that doesn’t need a bulky and dangerous battery to power it. Its creators claim that it consumes almost zero power, a feat that has been achieved by using existing components from the world of wireless communication. The cell phone can transmit speech data and receive incoming speech data. The researchers also demonstrated a Skype call that involved receiving calls, dialling calls and putting callers on hold. While all of this is amazing, it still is unbelievable to see a device do conventional mobile telephony while drawing zero power.

Well, zero power doesn’t mean absolutely powerless. In fact, it requires 3.5 microwatts of power to operate, which is equated to negligible. The reason behind the extremely low power consumption is because the cell phone uses ambient wireless signals as its primary way to communicate with the other device. Existing mobile phones have a complicated step of converting analogue signals into digital ones, which is understandable by computers but requires a lot of power to do that. By eliminating the conversion, you have a device that uses less power, which is what the scientists have achieved.

During a call, the cell phone uses vibrations from the microphone to encode speech pattern in ambient signals for sending voice data. To receive the audio signals, it converts encoded radio signals to sound vibrations, which are picked up by the speaker. The prototype device shown in the demo had a button to switch between transmitting as well receiving modes.

The team designed a separate base station to transmit as well as receive radio signals, which they say could be integrated with existing cellular network infrastructure or home Wi-Fi networks. “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 cell phone coverage everywhere,” said Vamsi Talla, a research associate at UW.

Since the cell phone still requires a minimum amount of power, the researchers have also suggested two ways to harvest it from two different ways – using ambient radio signals from a base station up to 30 feet away or by using a tiny solar cell as big as a grain of rice.

(Source)