From microwave ovens to Wi-Fi connections, the radio waves that permeate the environment are not just signals of energy consumed but are also sources of energy themselves.
An international team of researchers, led by Huanyu “Larry” Cheng, Dorothy Quiggle Career Development Professor in the Penn State Department of Engineering Science and Mechanics, has developed a way to harvest energy from radio waves to power wearable devices.
The researchers recently published their method inMaterials Today Physics.
According to Cheng, current energy sources for wearable health-monitoring devices have their place in powering sensor devices, but each has its setbacks. Solar power, for example, can only harvest energy when exposed to the sun. A self-powered triboelectric device can only harvest energy when the body is in motion.
“We don’t want to replace any of these current power sources,” Cheng said. “We are trying to provide additional, consistent energy.”
The researchers developed a stretchable wideband dipole antenna system capable of wirelessly transmitting data that is collected from health-monitoring sensors. The system consists of two stretchable metal antennas integrated onto conductive graphene material with a metal coating.
The wideband design of the system allows it to retain its frequency functions even when stretched, bent and twisted. This system is then connected to a stretchable rectifying circuit, creating a rectified antenna, or “rectenna”, capable of converting energy from electromagnetic waves into electricity. This electricity that 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. Compared to other sources, less energy is produced, but the system can generate power continuously – a significant advantage, according to Cheng.
“We are utilizing the energy that already surrounds us – radio waves are everywhere, all the time,” Cheng said. “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.”
Cheng said that this technology is a building block for him and his team. Combining it with their novel wireless transmissible data device will provide a critical component that will work with the team’s existing sensor modules.
“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.”
Related Posts
- 41
A new wearable device turns the touch of a finger into a source of power for small electronics and sensors. Engineers at the University of California San Diego developed a thin, flexible strip that can be worn on a fingertip and generate small amounts of electricity when a person's finger… - 37
Power plants generate electricity and send it into power lines that distribute energy to nodes, or sites, where it can be used. But if the electricity load is more than the system's capacity, transmission can fail, leading to a cascade of failures throughout the electric grid. This domino effect was… - 35
At the beginning of 2020, for the first time ever, renewable energy was able to cover more than half of the electricity consumed in Germany. But the more important renewable energy sources become, the more urgent is the need to store the electricity produced in this way. Green energy could… - 34
Current research on flexible electronics is paving the way for wireless sensors that can be worn on the body and collect a variety of medical data. But where do the data go? Without a similar flexible transmitting device, these sensors would require wired connections to transmit health data. Huanyu "Larry"… - 34
A startup company called Tau, which specializes in materials science and automotive electrification, says it has delivered a prototype wire that enables electric motors to double their power output without changing their size. The technology could mean that electric vehicles and machines of all kinds can keep going for longer…