Composite Functional Metasurface with Microwave Absorption and Vibrational Energy Harvesting

Abstract This paper designs and validates a composite functional metasurface that combines microwave absorption and vibrational energy harvesting. The metasurface is composed of an indium tin oxide (ITO) electrically conductive glass pattern layer, arrays of 1‐ethyl‐3‐methylimidazolium dicyanamide [EMIM][N(CN)₂] droplets, and an underlying indium tin oxide (ITO) electrically conductive glass layer. The composite functional metasurface possesses broadband absorption performance when the microwave frequency bands are between 7.34 and 22.63 GHz, which can transform vibration energy into electrical energy simultaneously. The relationship between output power, the number of droplets, internal resistance, and the matching load of the composite functional metasurface is deeply studied. It is found that the internal resistance decreases with the increase in the number of droplet arrays. The effective output power reaches up to 125nW when there are 48 droplet arrays. This technology has promising applications in the field of intelligent and portable electromagnetic devices.