A graphene device harvests ambient radiation to power battery-free sensors
Researchers design an ultra-low-power temperature monitor that runs for at least 24 hours on energy scavenged from domestic wiring
By Letizia Giugliano
2 min readHuman-Edited, AI-Assisted
Physicists and materials scientists from the United States have built a graphene-based device that harvests energy from ambient electromagnetic radiation to operate an ultra-low-power temperature sensor. The prototype can function continuously for at least 24 hours during a power outage without requiring chemical batteries.
Scavenging energy from household electrical wiring
Traditional wireless monitors rely heavily on electrochemical batteries, which run out of power and require routine physical replacement. To overcome these limits, an engineering team has introduced an innovation in ambient energy harvesting reported by Interesting Engineering. Physicists and materials scientists at the University of Arkansas and the University of Michigan built a device that draws operating electricity directly from the magnetic fields that surround standard electrical wiring in modern homes.
The development marks the team's second self-powered sensor prototype, following an earlier design powered by solar energy. Together, both units form part of a broader push to produce autonomous hardware that satisfies three baseline benchmarks: scavenging power locally, consuming only nanowatts of electricity, and operating unattended across years or even decades.
“The inductor adds charge to these capacitors at a slow rate, but it’s faster than the rate the sensor uses up the charges from the capacitors”
— Paul Thibado, physics professor at the University of Arizona
How the graphene inductor and capacitor circuit works
At the heart of the system is a graphene inductor engineered to collect energy from ambient electromagnetic radiation. According to Paul Thibado, a physics professor at the University of Arizona who began studying graphene properties nearly a decade ago, the captured energy moves through a specialized circuit where it is transformed into electricity and held in storage capacitors that run the temperature sensor.
Because the circuit replenishes the capacitors faster than the temperature sensor depletes them, the hardware maintains continuous operation during interruptions. Thibado reported to Interesting Engineering that this stored power sustains the sensor for at least 24 hours during a blackout, and potentially for as long as a week depending on operating conditions.
Lower maintenance and the future of self-powered IoT
By eliminating routine battery swaps, the invention offers a sustainable "set it and forget it" profile that sharply reduces maintenance labor, operational expenses, and hazardous battery waste. This independence makes the units well suited for locations where manual servicing is impractical, such as shipping containers, environmental tracking systems for soil and atmosphere, logistics fleets, wearable fitness equipment, and healthcare monitors.
Moving forward, the researchers plan to integrate multiple energy-scavenging mechanisms into a single unit, as detailed by Interesting Engineering. Future iterations are slated to combine ambient radiation collection with systems that harvest energy from sunlight, heat, sound, and motion. By blending diverse ambient sources, the devices could maintain uninterrupted operation even if one source lapses, paving the way for autonomous smart electronics across the Internet of Things.
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