Using Energy from Radio Waves to Charge Wearable Electronic Devices

Technological Innovation Would Help in Reliability and Usability of The Device

From microwave oven to Wi-Fi connectivity, the emitting radio waves that saturate into the environment are not entirely just energy signals consumed and are even sources of energy as well. A group of international researchers working at the Penn State Department of Engineering Science and Mechanics has been able to develop a way through which they would be able to harvest the energy sources emitted from the radio waves in an attempt to power the wearable electronic devices.

The method used by the researchers has been recently published in the journal named Materials Today Physics.

According to one of the scientists working on this project, the currently used energy source installed in wearable electronic devices used for monitoring of health has their designated place in powering of the sensor devices, although each one of them has its own setbacks. The power from solar energy can only be obtained when the harvesting material is exposed to the sun, only during the daytime. In the case of a self-powered triboelectric apparatus are only able to store energy when the body is in dynamic motion for some time.

Although the researchers do not want to replace the power sources being currently used around the world but are in search to provide an additional and consistent source of energy, including powering of wearable electronic devices.

Radio Frequency energy is currently being broadcasted from tens of millions of radio transmitters all across the world, including telephones, radios, broadcasting stations, or mobile base stations. The ability to harvest the RF energy from either the dedicated or ambient sources available enables the function of wireless charging of devices that require low power and has been observed to have benefits in the design, reliability, and usability of products.


The researching team of scientists has been able to develop an antenna system with a stretchable wideband dipole attached to it which has the capability to transmit data wirelessly, which has been collected by the health-monitoring sensor device. The developed system also has metallic antennas that are easily stretchable and integrated onto a graphene material with is conductive in nature, along with a coating of metal all over it.

The wideband design allows the system to be able to retain its functions of frequency while stretching, bending, and even twisting. As the system is connected to a stretchable rectifying circuit, resulting in the formation of a rectified antenna, which can also be called a ‘rectenna’, and has the capability to convert electromagnetic waves from the environment into electrical energy.

This rectenna system has the capacity to convert electromagnetic and radio waves from the surrounding environment and into a viable energy source that would be able to power the sensory modules of the wearable electronic device. This wearable electronic device is able to track the body temperature, levels of hydration, along with pulse oxygen levels of the individual.

Utilization of energy sources

When compared with other sources of energy, there is less amount of energy production, although the system has the capability to generate continuous power when required for the wearable electronic device, which is a significant advantage of this device.

The researchers are working to utilize the energy that is already present in our surroundings, including radio waves, as they are easily accessible everywhere, every time all around us. If we are unable to use the ambient amount of energy surrounding us, it simply goes to waste. By this method, the energy source can be harvested and rectified into a viable power source.

This technological advancement during wearable electronic devices is a building block for the research team currently working on this project. By combining this technology for wearable electronic devices with their wireless transmittable data devices, will be able to give them a critical component that will be able to work alongside the existing sensor modules developed by the team.

The next possible step for the team would be to explore the miniaturized version of the circuits, along with working on developing a stretchable rectifier. The wearable electronic devices are a platform in which they would be easily able to combine and apply the technological innovations with other modules, which they had developed in the past. This can easily be adapted or extended for other technological applications; meanwhile, the team is also working to explore other opportunities.

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