Editor’s Note: The following Q&A is the first in the Sensors Converge Speakers Series
Q: Sanjay, you are moderating a panel on June 22 at Sensors Converge 2023 entitled, “How emerging markets and new applications are utilizing energy harvesting systems.” So, here’s a basic question: what is RF energy harvesting?
Gupta: RF energy is everywhere around us. It is, after all, RF signals we use for all of our wireless communication needs – cellular, Wi-Fi, Bluetooth, and more. RF energy harvesting involves using this ambient RF energy to power devices. Given that the ambient energy is quite small and it is today impractical to power meaningful devices with it, RF energy harvesting systems today deploy purpose built RF transmitters. The AirFuel Alliance recently approved the standard for RF energy harvesting, AirFuel RF, that enables deployment of interoperable RF energy transmitters and receivers.
Q: Can you name hot emerging markets or new apps that use energy harvesting…or at least groups of apps?
Gupta: RF energy harvesting is an ideal fit in applications that require small amounts of energy, such as IoT devices. With RF energy harvesting, we can now build and deploy IoT sensors that do not require batteries to power them. So no more hassle of periodically replacing the batteries or dealing with the e-waste of depleted batteries.
Another interesting application of the technology is the electronic store shelf displays. Their adoption has been slowed because of the use of batteries and the need to periodically replace them. With RF power harvesting, these can now be made without batteries and can go on and on with zero attention. At the end, if there is a device that needs small amounts of power, say milliwatts and below, it can be powered via RF energy harvesting.
Q: What are the major benefits?
Gupta: Who loves wires? By eliminating the wires, we can now place the devices in ideal locations without having to worry about the cost and hassle of running wires. This further allows us to reconfigure the layout and the location of devices with minimal effort. Eliminating batteries allows us to, one, reduce the cost of the IoT devices and, two, reduce the batteries and the toxic chemicals in them from ending in a landfill.
Q: Are there any downsides? Any gotchas for developers or entrepreneurs?
Gupta: Like any other wireless product, RF Energy harvesting systems must comply with appropriate regulations. Failure to plan for regulatory approvals early in the engineering process can be painful later. Following the AirFuel RF standard is beneficial here.
Q: Wireless technologies rely on standards for large scale market adoption. Do we have other standards being worked on for RF energy harvesting?
Gupta: AirFuel Alliance is a global industry standards organization and is working on specifications for next generation wireless power technologies – specifically those technologies that allow spatial freedom for devices and allow energy to be delivered to multiple devices, each requiring different amounts of energy simultaneously. AirFuel Alliance recently approved the specifications for RF Wireless power. (For more information: www.airfuel.org.)
Q: Is there an engineering/design specialty or a class that a young engineer or student should take to prepare for work in energy harvesting?
Gupta: For those looking to learn more about RF wireless power and integrating the technology in their products, I would strongly recommend joining the AirFuel RF course being hosted by AirFuel Alliance. Industry experts will lead the course and be available to answer all your questions (To register, please go online.)
Sanjay Gupta is moderating “How emerging markets and new applications are utilizing energy harvesting systems” at Sensors Converge on Thursday, June 22, at 9:45 a.m. PDT. In addition to serving as president of AirFuel Alliance, he attained a Ph.D. in Systems and an M.S. in Electrical Engineering from the University of Pennsylvania. He holds more than 25 patents and is best known for delivering the first phone with Wi-Fi and VoIP calling and the first smartwatch.