A US startup has just unveiled a prototype system for transforming electricity into ultrasound and back again. This invention could have major implications for high-tech devices and objects.

uBeam Promises to Recharge Your Smartphone Using Ultrasound

Recharging your telephone or your computer remotely without having to plug it in – this is the promise held out by uBeam, a small startup which has just publicly demonstrated its first fully functional prototype. The invention transforms electricity into sound at a charging station and sends the audio through the air over ultrasound. A receiver attached to the portable electronic device that you wish to charge up then catches the sound and converts it back into electricity to feed the device’s battery. “This is the only wireless power system that allows you to be on your phone and moving around a room freely while your device is charging,” claims uBeam founder and CEO Meredith Perry.  Induction charging has of course been invented but then the electronic device has to be placed on or near to a base station to charge up.

Rather like WiFi       

“It allows for a WiFi-like experience of charging,” explained the 25-year-old palaeobiology and astrobiology graduate in an interview with the New York Times. By this she means that telephones, computers and other electronic devices can be charged when moving around the room, even if they are in your handbag or trouser pocket. There is however one major qualification to the uBeam CEO’s assertion: ultrasound cannot pass through walls, which means that a separate charging station will be needed for each room. Three years into development, the system is still not ready for the market and uBeam, whose headcount still numbers less than ten, reckons it needs another two years before its equipment will be on your store shelves. The company is planning to make two different charging products at first. One will be designed for smaller rooms, e.g. in homes, offices and coffee shops, while the other will be built for much larger spaces such as hotel lobbies, conference halls and stadiums.

Impact on battery manufacture

The uBeam invention has a number of major implications. “If wireless power is everywhere, then the size of your battery can shrink because it’s always charging,” Perry points out. In other words, smartphone manufacturers will no longer have to rely on the development of ever more powerful and high-performance batteries. This means slimmer size, lower weight and lower cost. So this technology could be particularly useful for wearable electronics. Manufacturers will no longer have to juggle size against power autonomy, consumers will no longer have to take off their watches, wristbands and Google Glasses to recharge them and international travellers will be able to leave their bulky adapters at home. Moreover, in the not too distant future, “in addition to your local coffee shop saying it has free WiFi, it will also say it has free uBeam,” is Meredith Perry’s ambitious claim.

By Jérôme Marin