You can use WiFi to charge your iPhone

Harvesting the excess energy from radio frequencies could be used to reduce the carbon footprint of electronic devices.

Electromagnetic waves are all around us. Buildings are filled with numerous WiFi hotspots, phones connected to wireless headphones, and laptops linked to printers, speakers, and other electronics via Bluetooth.

Wireless routers release energy in the form of electromagnetic waves, specifically radiofrequency (RF) radiation. This energy is what allows the router to transmit data wirelessly to various electronic devices.

Researchers at Tohoku University, the National University of Singapore, and the University of Messina in Italy have found a way to harness an environment’s excess energy and transform it into direct-current (DC) power.

Small devices can capture this energy, decreasing reliance on batteries, prolonging their lifespans, and lowering environmental impact. Instead of traveling to remote areas to frequently replace batteries, these devices can be powered remotely by ambient energy sources like common RF wireless signals.

In a research paper published in Nature Electronics, scientists explain how they enhanced the previously known 'rectifier' technology to increase efficiency in energy conversion.

Rectifier technology converts alternating current (AC), which changes direction, into DC, which flows in one direction. This is done using components like diodes that allow current to pass through in only one direction.

Existing technologies, such as the Schottky diode, have faced challenges in effectively converting energy. Scientists overcame these challenges by developing a compact nanoscale spin-rectifier (SR) to convert ambient wireless RF signals less than -20 dBm to a DC voltage.

Currently, the signal source generally needs to be in close proximity to the electronic device, but scientists are working to advance the technology. The team is investigating the integration of an on-chip antenna to enhance efficiency and compactness.

They are also developing series-parallel connections to tune impedance in large arrays of SRs, using on-chip interconnects to link individual SRs.

According to scientists, RC technology can be easily integrated into energy harvesting modules to power electronic devices and sensors, enabling battery-free operation.

The study of this technology could pave the way for a self-sustaining, eco-friendly energy solution that has the potential to address many future challenges.