Researchers from Far Eastern Federal University (FEFU), the Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, and Chinese scientific centers have created a device that can generate electricity around the clock due to temperature differences.
The development is based on a thermoelectric generator. In devices of this type, current is generated due to a temperature difference on two sides. However, this temperature difference needs to be maintained constantly – this is the problem the scientists solved.
Special microstructured plates are attached to the generator on both sides. The first is made of silicon, covered with an array of sharp microcones, inspired by the structure of a night moth's eye. Thanks to its anti-reflective properties, this surface absorbs up to 95% of sunlight and efficiently converts it into heat. During outdoor tests, it heated up significantly more than the ambient air.
The second plate consists of silicon dioxide. It provides passive cooling, allowing thermal radiation to escape into space. The device was tested in different seasons. It worked best in summer, when there is more sunlight, but generation did not stop even at night – due to the cooling of one of the surfaces.
As noted by Alexander Kuchmizhak, co-author of the study and an employee of FEFU and IAPU FEB RAS, for now, it's about collecting a small amount of energy, but the principle of sustainably creating a temperature difference without active cooling is important. The results lay the foundation for scaling and optimizing the designs of thermoelectric devices.