Flexible metamaterial electromagnetic harvester using modified split-ring resonator

—In this paper, a flexible metamaterial-based electromagnetic harvester is proposed for wearable applications at microwave regime. The proposed harvesting structure is composed of a modified configuration from the conventional Split-Ring Resonator (SRR) inclusion and is printed on a grounded very thin flexible substrate. The proposed wearable harvester structure provides several interesting features, including its robustness, sustainability, and ease of integration with flexible electronics and sensors. Numerical full-wave studies are conducted, where results from a periodic arrangement of the proposed harvesting unit cell along with several two-dimensional arrays of harvesters are presented and discussed. Based on the numerical studies, the proposed electromagnetic harvesting structure exhibits good efficiency capability of power conversion from radio frequency received power to alternating-current harvested power across collecting loads above 90% for the three studied cases.