Wireless charging of devices is nothing new. Smartphone users know the principle: simply place the phone on the charging pad and the battery will start charging.
But what if you could always use your phone without a battery?
Scientists at the National University of Singapore are working on this, he writes “Winter”.
Scientists have developed a prototype module to harvest energy from thin air, so to speak. Specifically, it is a module (and technology) that converts ambient or “waste” radio frequency signals into DC voltage, which can then be used to power small electronic devices without the use of batteries.
As they emphasized during the prototype presentation, radio frequency energy harvesting technologies are important because they reduce dependence on batteries, extend the lifespan of devices, reduce environmental impact, and increase the feasibility of wireless sensor networks and remote devices – areas where frequent battery replacement is impractical.
Scientists face challenges
However, they add that such technologies face challenges due to the low ambient power of the radio frequency signal. Rectifier technology either does not work or has low efficiency in converting radio frequencies into direct current.
Therefore, a team of researchers in collaboration with scientists from Tohoku University in Japan and the University of Messina in Italy developed a compact and sensitive technology.
The team optimized these rectifiers and designed two configurations – one operating between minus 62 dBm and minus 20 dBm and a series of 10 rectifiers in series in a power harvesting module. The result was a successfully operating commercial temperature sensor with at least 27 dBm.
“Capturing high-frequency electromagnetic signals from the environment is critical for improving energy-efficient electronic devices and sensors. However, existing energy harvesting modules face challenges in low-power operation due to limitations in existing rectifier technology,” explained Professor Yang Hyunsu of the Department of Electrical and Computer Engineering, College of Design and Engineering, who led the project.
The experimental research was carried out in collaboration with Professor Shunsuke Fukami and his team from Tohoku, while the simulation was carried out by Professor Giovanni Finocchio from Messina. The results were published in the prestigious journal Natural Electronicson July 24, 2024.
The research team is now investigating antenna-on-a-chip integration to improve the efficiency and compactness of rectifier technologies. They also intend to collaborate with industrial and academic partners to advance self-powered intelligent systems based on such on-chip rectifiers.
This could pave the way for compact on-chip technologies for wireless charging and signal detection systems.
