The device's transparency, due to its construction from indium tin oxide, broadens its potential applications. (Representational image) yacobchuk/iStock
In a major development, researchers have created a transparent device that can harvest energy from both radio waves and sunlight to power a wide range of wireless devices.
“In this paper, an optically transparent rectifying metasurface system (RMS) is designed and validated for simultaneously harvesting radio frequency (RF) energy while enabling the efficient transmission of visible light,” said the researchers of a new study.
Traditional energy harvesting systems have typically focused on a single energy source, such as radio frequency or solar power. This singular approach presents inherent limitations, as the availability of any single environmental energy source can be intermittent and unpredictable.
However, the new study tries to overcome these limitations by developing a device that effectively harvests energy from two abundant and readily available sources. This dual-source strategy maximizes energy capture and ensures a more consistent and reliable power supply.
Transparent, versatile design
The device’s fabrication from indium tin oxide, a transparent conductive material, further enhances its applicability. This material property allows for seamless integration into various surfaces and devices without compromising aesthetics or functionality.
“The energy harvester is based on indium tin oxide — a material that cannot be seen in visible light,” stated author Liming Si, as reported by journal AIP.
Notably, its potential applications are diverse, ranging from self-powered windows and displays to energy-harvesting building facades and vehicle components.
“Our transparent rectifying metasurface system offers distinct advantages over conventional energy harvesting antennas and metasurfaces, including wide-angle coverage, a low-profile design, polarization insensitivity, and high optical transparency,” added Si.
To optimize energy harvesting, the researchers incorporated a voltage-doubling rectifier circuit designed to capture energy within the 2.4 and 5.8 GHz Wi-Fi bands.
These frequencies were selected due to their prevalence in modern wireless communication environments, ensuring a consistent and readily available source of radio frequency energy.
Performance validation
“To validate its performance, a prototype 3 × 3 optically transparent metasurface absorber (OTMA) array was designed, fabricated, and measured,” highlighted the study.
The integration of the energy harvester with a solar cell resulted in a notable increase in the solar cell’s maximum power output, demonstrating the synergistic potential of this dual-source approach.
“Results demonstrate that the fabricated RMS achieves RF to DC efficiencies of 19.64% at 2.4 GHz and 7.92% at 5.8 GHz, with an impressive 80% optical transparency,” asserted the researchers.
“Furthermore, solar energy harvesting tests show that the measured maximum power point for the RF/solar hybrid energy harvesting is 13.11% higher than that of a single solar panel.”
The development of this transparent, dual-source energy harvesting device marks a significant step towards addressing the growing energy demands of our increasingly interconnected world.
By enabling the seamless integration of energy harvesting capabilities into a wide range of surfaces and devices, this technology offers a promising pathway towards a more sustainable and energy-efficient future.
