Forget batteries! This device turns Wi-Fi signals into electricity
A team of researchers from the National University of Singapore (NUS) has developed a revolutionary technology capable of converting ambient radio frequency (RF) signals, such as those from Wi-Fi and cellular networks, into usable electricity. The innovation transforms typically wasted energy into direct current (DC) voltage, potentially eliminating the need for batteries in various electronic devices.
Nanoscale spin-rectifiers: The key to efficient energy conversion
The research team utilized nanoscale spin-rectifiers (SR) to convert RF signals into DC voltage, even at low RF power levels below -20 dBm. Traditional rectifiers, such as Schottky diodes, struggle to operate at low power due to thermodynamic constraints and parasitic effects. However, nanoscale spin-rectifiers offer a more compact and efficient solution. "Nanoscale spin-rectifiers offer a compact technology for sensitive and efficient RF-to-DC conversion," said Professor Yang Hyunsoo, who led the project.
Spin-rectifiers surpass traditional diodes in efficiency
The team optimized these SR devices and created configurations that operated effectively across a wide power range. They coupled the SRs in an array arrangement to improve output and achieve on-chip operation. An array of 10 SRs achieved an impressive 7.8% efficiency and high sensitivity. "Spin-rectifier technology offers a promising alternative, surpassing current Schottky diode efficiency and sensitivity in the low-power regime," said Dr. Raghav Sharma, the first author of the paper.
Future developments in RF energy harvesting technology
The research team is now focusing on integrating an on-chip antenna to further enhance the efficiency and compactness of their technology. The scientists are also considering series-parallel connections and on-chip interconnects to improve RF power harvesting, with the potential to generate enough voltage to eliminate the need for a DC-to-DC booster. "This advancement benchmarks RF rectifier technologies at low power, paving the way for designing next-generation ambient RF energy harvesters and sensors based on spin-rectifiers," Sharma said.
