NUS team harvests WiFi signals to power electronics

Widespread use of the 2.4GHz radio frequency due to the growth of WiFi sources means excess signals are currently inactive and available for alternative uses when not being utilised to access the Internet.

NUS researchers have now worked with Japan’s Tohoku University (TU) on the development of a technology that uses tiny smart devices known as spin-torque oscillators (STOs) to harvest and convert these wireless radio frequencies into energy. 

“In this way, small electric gadgets and sensors can be powered wirelessly by using radio frequency waves as part of the Internet of Things,” said project leader Prof. Yang Hyunsoo, NUS Department of Electrical and Computer Engineering. “With the advent of smart homes and cities, our work could give rise to energy-efficient applications in communication, computing and neuromorphic systems.”

The application of STOs in wireless communication systems is often hindered by low output power and broad linewidth. This can be overcome by mutual synchronisation of multiple STOs, but current schemes, such as long-range magnetic coupling between multiple STOs, have spatial restrictions.