Radio Wave Power: New Technology Generates Power from Radio Frequencies

Could invisible radio frequencies be the future of the smart city Internet of Things revolution?

Author Mark Newton, 01.16.23

Translation Sarah-Indra Jungblut:

Our busy urban spaces are already crowded and crammed with a whole manner of machines, people and buildings — resulting in sprawling concrete jungles. But the air itself is also filled with invisible informational traffic. Wifi signals, radio waves and telecommunications are constantly crisscrossing our environment – and now a new approach is looking to harvest them for power.

A research team at the University of Central Florida’s Department of Electrical and Computer Engineering have developed a new prototype system which can use the otherwise wasted electrical potential of radio frequencies. In particular radio frequency electromagnetic waves — the most abundant in most populated areas — have the potential to power ultra-low powered devices without the need for batteries or even sensors.

To harvest this power, the UCF device makes use of piezoelectric materials — which generate an electrical charge through mechanical stress on solid objects. These stresses can be as subtle as minor vibrations in the air, and it has long been theorised that radio waves or sound waves can also be used to generate a charge in some devices. The UCF invention, in particular, takes advantage of the energy exchange mechanism between microacoustic waves (the basis for most of radio frequency signal processing) and electrons.

Radio frequencies and their microacoustic waves are detected by the device and passed over a piezoelectric material placed upon a semiconductor. The effect of the waves upon the material generates a current which is converted into direct current for use by the attached device.

One issue that has limited the practicality of using radio waves as a source of power is the requirement to sense and transmit signals which also require power. To solve these issues, the UCF researchers have developed a technology that integrates power scavenging and spectrum sensing capabilities into a passive module. This would therefore eliminate the need for power-intensive sensing modules. It would also be possible to store this energy in a capacitor or battery if required.

Another issue concerns the availability of the radio spectrum needed to generate power. The conversion occurs within a sub-millimetre radio wave footprint and within a specifically defined frequency range. To tackle this problem, the device has also been developed to handle more ‘intelligent’ data transmissions between smart Internet of Things nodes and understand the occupancy of frequencies in the area.

In layman’s terms, this would allow a device to scavenge energy from the radio frequency power emitted from nearby IoT nodes.

The 1.5 degree target is unattainable without a real transformation of our energy system. But how can it succeed? What are the energy sources of the future? What digital solutions are ready and where are innovations needed? And how can the transformation be driven forward?

The RESET Greenbook “Energy Transition – The Future is Networked” presents digital, innovative solutions and sheds light on the background.

The concept is especially geared towards powering low-powered IoT sensors and devices — especially in an urban environment. The requirement for power — either from a solar panel or onboard battery — places practical limitations on these devices. Solar panels must be a certain size and have constant access to sunlight, something which is not guaranteed in urban areas with tall buildings. Meanwhile, batteries need to be changed and add extra expense. In theory, a device harvesting power from radio waves could generate power more consistently and at a reduced cost in terms of maintenance and construction.

Currently, a prototype has been constructed by the team, and they are now seeking partners for production.

No Wires Attached

Although transmitting power wirelessly may seem like highly advanced technology, it has long been considered and experimented with. Nikolai Tesla theorised such technology, and it came to fruition in the 1960s with the rectenna — a compound of ‘rectifying’ and ‘antenna’.

Today, rectennas are largely used in radio frequency identification tags, like those used in logistics, passports and animal tracking. These barcode-like devices do not need line-of-sight with a scanner to function and can be temporarily powered when in the presence of certain radio waves. Other applications include proximity and contact smart cards.

However, radio wave power transfer is also being discussed as a way of potentially beaming solar energy from space or consistently powering vehicles such as drones.

Powering the Internet of Things Using Just Indoor Light

The Internet of Things is already all around us, but how to power all those connected sensors and devices stil poses a huge challenge.

The Internet of Things

The Internet of Things has been hailed as the biggest technological revolution of our era, with the power to transform our day to day lives, agriculture, industry and maybe even turn the economy on its head. But what does it actually mean? How will it affect our lives? Are there any potential dangers? And could the IoT help us live more sustainably?

Can Civic Technology Help You Fix Your City from Your Smartphone?

All too often, living in a city can make you feel like a passive bystander. But new civic technology is aiming to make it easier than ever to get involved and have your voice heard.

© Gregor Fischer
Civic Tech – How Citizens Shape the Future with Digital Technologies. Interview with Geraldine de Bastion

For Geraldine de Bastion, digitisation is a development that we can - and must - actively shape. And also that we should use digitization for more climate protection. We talked to her about civic tech in environmental and climate protection and the challenges of digital engagement.

How Sensors on Walls and Balconies Can Help Citizens Clean Up Air Pollution

The air in our cities is polluted. With sensors, citizens can collect measurements, allowing them to uncover sources and build up political pressure.

Interview: How Can Citizens and Civil Society Use Civic Tech to Initiate Change?

What is civic tech and how can it facilitate political protest? Daniel Staemmler from Humboldt University Berlin answers these questions.

Wireless AI Sensors Can Give Ultra-Early Warnings of Growing Wildfires

If wildfire can be caught early, they are much easier to tackle. Networked AI sensors are providing the tools to give fire crews a head start.

© Torge Peters/ Studio Nørden
Civic Tech: Citizens Drive Environmental and Climate Protection with Public Data, Apps and Platforms

With citizen-owned digital tools, environmental data and government knowledge can become part of the common good and starting point for change.