Startup GuRu Wireless Inc. (Pasadena, Calif.) is looking to invigorate the market for wireless power transfer with its beam-formed version of technology.
GuRu Wireless was spun out of Caltech in Pasadena in 2017. The name derives from the pairing of a generating unit (GU) and a receiving unit (RU), which is at the heart of the company’s offer. This allows the deliver of power ranging from a few watts to a couple of hundred watts across distances from a few meters to over hundreds of meters.
The system utilizes 24GHz phased arrays and proprietary smart lensing technology. The system architecture is designed in a tiled format that allows scaling for different use cases, form factors and power/distance requirements.
Narbeh Derhacobian, CEO of the company, sat with eeNews Europe and observed that so far wireless power transfer has divided into two categories; what he called proximity power at less than one meter and remote power at more than one meter.
If you can, plug it in
Several companies have tried to sell wireless power, usually in the first category, but they have focused on the convenience of not having to plug something in. “The reality is that the technical constraints, the cost and regulation combine to squeeze out almost all such applications,” Derhacobian said.
There is also the consideration that wireless power transfer is by far less efficient and transferring power than copper, he said. Derhacobian gave the example of wireless charging of a smartphone. It has not caught on because what was being offered was minor convenience at higher cost and inefficiency, he said.
GuRu Wireless’ approach is to try and improve the efficiency by beam-forming but also to look for applications where any inefficiency of power transfer is more than compensated for by enabling something that is otherwise not possible and/or the provision of environmental and sustainability benefits. These could include removing the need for batteries, their replacement and disposal. The 24GHz also gives the possibility of providing a two-way communications channel between the generation unit (GU) and receiving unit (RU).
Most wireless power transfer technologies have used RF at 950MHz or 2.45 to 2.8GHz.
Advantages of 24GHz
GuRu’s use of 24GHz millimeter wave technology has the advantages of being in an ISM electromagnetic frequency band and by operating at high frequency reduces the size of antenna proving form-factor flexibility, Derhacobian said. The advantage is illustrated by the ability to transfer power, which can be up to 200W at 100 meters distance.
Although 24GHz wireless power transfer can be much more efficient at distance than alternative methods it is also important to pick the right applications, Derhacobian said.
He gave the example of a quadcopter drone. This are used in consumer, professional and defense applications and usually run on batteries with an airborne time of 20 to 30 minutes. For some applications the military have opted for tethered drones to receive continuous power but that is not always possible, when a unit is moving through forest, for example. Persistent intelligence, surveillance and reconnaissance (ISR) is of interest to the DoD he added.
GuRu has demonstrated almost indefinite air-time for an untethered quadcopter. “It was up for 96 hours and we only brought it down because we were bored,” said Derhacobian.
“In situations like humanitarian disasters, floods and so on, the efficiency of the power transfer is no longer so relevant. The UAV has to stay up. And at 4.5GHz or 5.8GHz the antenna would be 10 times the size of the drone.”
No retrofit required
“It is often impractical to rewire commercial buildings to retrofit technology-based options, such as sensors and fixtures. This means they are often battery operated and batteries need replacement. In building such as an airport or hospital that can mean complete replacement every three or six months,” Derhacobian said. “Beaming power means never having to change a battery,” he offered. “Trickle charging sensors can provided a much better return-on-investment than endlessly replacing batteries,” he concluded.
GuRu has just received a Small Business Innovation Research (SBIR) grant from the US Department of Energy’s (DOE) Building Technologies Office (BTO). GuRu Wireless will use the grant to fund research on integrating the wireless power and control of electrochromic windows. This can make for building upgrades for energy-efficiency without the cost of rewiring for power.
The GuRu Wireless system can not only power and control several windows but can also act as an access point for data aggregation within a building, as the company’s transmitters can connect to internal building networks and to cellular networks.
The proof-of-concept will be installed in a government laboratory and could then form the basis of a commercial grade solution.
Related links and articles:
News articles
Millimetre wireless power for sustainable windows
Energous sees first FCC 2W wireless power certification
Beam steering ultrasound for wireless power to medical implants
Powercast, Powermat team wireless power