A team of scientists at the Penn State Department of Engineering Science and Mechanics has developed a new method of harvesting energy from radio waves to power wearable devices, As per a press release by the university.
Their new method published in Materials Today Physics.
“We are utilizing the energy that already surrounds us — radio waves are everywhere, all the time,” lead author Huanyu Larry Cheng said.
He also added “If we don’t use this energy found in the ambient environment, it is simply wasted. We can harvest this energy and rectify it into power.”
For example, every time we call someone or when we connect to a website, electromagnetic waves (EM Waves) spread out unless they are blocked by an object. Since in a given second, billions of people are making phone calls, we are bombarded with EM waves everywhere we go. These waves, although possessing very little power, can be sources of energy.
The Scientists developed a stretchable wideband dipole antenna system capable of wirelessly transmitting data that is collected from health-monitoring sensors. The system consists of 2 stretchable metal antennas integrated onto conductive graphene material with a metal coating.
The wideband design of the system permits it retains its frequency functions even when stretched, bent and twisted. This system is then connected to a stretchable rectifying circuit, making a rectified antenna, or “rectenna,” capable of converting energy from EM waves into electricity.
This electricity can be used to power wireless devices or to charge energy storage devices, such as batteries and supercapacitors.
This rectenna can convert radio, or electromagnetic, waves from the ambient environment into energy to power the sensing modules on the device, which track temperature, hydration, and pulse oxygen level.
According to Cheng, compared to other sources, less energy is produced, yet, the system can generate power continuously — a significant advantage.
Scientists now want to combine this technology with the novel wireless transmissible data device.
“Our next steps will be exploring miniaturized versions of these circuits and working on developing the stretchability of the rectifier,” Cheng said. “This is a platform where we can easily combine and apply this technology with other modules that we have created in the past. It is easily extended or adapted for other applications, and we plan to explore those opportunities.”