Distance Wireless Charging Made a Minor Comeback at CES 2022

It’s a similar story with Energous, which has announced an impressive range of partnerships and demonstrated its WattUp technology many times but has yet to reach consumers. Technovator hasn’t gone to market. Witricity pivoted into electric vehicles. Powercast was one of the first companies to release a consumer device, a wireless charging grip and transmitter for Nintendo Switch Joy-Con controllers, but it costs $150 and has a range of only around one foot. A killer product to drive adoption remains elusive.

Leveling Up

GuRu, the company behind Motorola’s demo, might be a few steps ahead of its peers. It employs RF lensing to send focused beams from a generating unit (Gu) to a recovery unit (Ru). Ali Hajimiri, a GuRu cofounder and it chief scientific adviser, shows me a pair of tiny chips with built-in antennas about the size of a Lego block and says the company has developed flexible materials that enable the technology to work in different types of devices.

“We are the only company that can do multiple watts of power to multiple devices at multiple meters, at the same time,” Hajimiri says.

I first met GuRu at CES 2020 to see Rovi, a mobile transmitter resembling a robot vacuum that moved to charge different devices, getting close enough to beam a useful amount of power. The company has made progress since then. Its technology combines an integrated ASIC (application-specific integrated circuit), an intelligent algorithm that can focus energy rapidly and efficiently in a small spot, and, crucially, a higher frequency to deliver more power at a longer range.

Most of these technologies started out at the 2.4-GHz frequency we are familiar with from Wi-Fi, and that’s also the frequency that charges up Samsung’s new remote most effectively. Energous uses the 5.8-GHz frequency, and Ossia is transitioning to 5.8-GHz with its Cota technology. A part of GuRu’s secret sauce is its ability to operate at 24 GHz. This jump doesn’t just mean more power and longer range, it also allows for smaller transmitters and receivers. A generating unit the size of a smartphone can charge an earbud over a distance of several feet.

“It’s like a magnifying glass where you can focus energy in one spot, but that spot can move, and you can make multiple spots,” Hajimiri says.

Chicken and Egg

This need for transmitters and receivers embedded into our products hampers the early adoption of wireless power over distance. It sounds convenient, but who will spend hundreds of dollars on a power router that supports a limited range of devices or requires another retrofit add-on to work?

“I think a good analogy for this technology is Wi-Fi,” Hajimiri says. “In the early days, you had to buy this big, clunky PCMCIA card to put in your laptop, and a lot of people would say, ‘I would never use Wi-Fi because my ethernet cable is 100 times faster.’”

Wi-Fi has improved enormously, and we accept a performance hit for the convenience of going wireless. Power could follow the same trajectory, and there are other potential benefits.