Researchers at the University of Arkansas have made a groundbreaking discovery that challenges long-established physics theories. They have found a way to harness energy from ambient heat using graphene, a one-atom-thick sheet of graphite. This breakthrough has significant commercial potential, especially for wireless sensors.
For over a century, it was believed that obtaining useful work from random fluctuations in a system at thermal equilibrium was impossible. However, the researchers have proven that freestanding graphene, when connected to a circuit with diodes having nonlinear resistance and storage capacitors, can produce useful work by charging the storage capacitors. This discovery overturns the physics orthodoxy and opens up new possibilities for energy harvesting.
The scientists conducted a series of experiments and demonstrated that the system satisfies both the first and second laws of thermodynamics. They also found that larger storage capacitors yield more stored charge, while a smaller graphene capacitance allows for a higher initial rate of charging and a longer discharge time. These characteristics are crucial as they give sufficient time to disconnect the storage capacitors from the energy-harvesting circuit before the net charge is lost.
This latest study builds upon the researchers’ previous work on the unique properties of graphene. In 2016, they identified the vibrational properties of graphene and its potential for energy harvesting. In 2020, they published a study on a circuit using graphene that can supply clean and limitless power for small devices or sensors.
The researchers aim to develop a device called a Graphene Energy Harvester (GEH), which uses graphene suspended between two metal electrodes. When the graphene flips up and down in response to ambient temperature changes, it induces a positive charge in the electrodes, creating an alternating current. By incorporating multiple GEH circuits on a silicon chip, more power can be produced.
NTS Innovations, a nanotechnology company, holds the exclusive license to develop GEH into commercial products. The small size of GEH circuits makes them ideal for mass duplication on silicon chips, allowing for widespread adoption. They can operate in various environments, making them particularly suitable for wireless sensors in locations where changing batteries is inconvenient or expensive.
Donald Meyer, founder and CEO of NTS Innovations, expressed confidence in the potential of Graphene Energy Harvesting technology, while Ryan McCoy, the company’s vice president of sales and marketing, highlighted the demand for smaller form factors and decreased dependence on batteries in the electronics industry.
This groundbreaking research by the University of Arkansas opens up a new avenue for energy harvesting by utilizing the ambient heat around us. The possibilities for applications are vast, and this discovery could have a profound impact on the way we power small devices and sensors in the future.
