Fabric Electromagnetic Energy Harvesting Platform Based on Absorbing Metasurface

In this communication, we propose a fabric electromagnetic (EM) energy harvesting (EH) platform using absorbing metasurface for body-worn application. The fabric EMEH platform contains the multiband absorbing metasurface, a matched rectifier circuit and an energy management circuit, in which the absorbing metasurface is composed of a periodic array of bow-tie dipoles and zigzag dipoles, enabling multiband operation across different frequencies. And unit cells of each column in absorbing metasurface array are connected to transfer and gather energy together by the build-in channel. The maximum simulated specific absorption rate (SAR) on a human torso model is 0.31 W/kg, lower than the maximum allowable limit of 1.6 W/kg. Then, a 5 × 5 array is designed and fabricated. Experimental results show that a dc power of 521 μW is collected from the source at 80 cm when the power density arriving at the absorbing surface is 19.69 uW/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. Further, to illustrate the potential of EMEH platform, we construct an autonomous and self-sustainable system for powering wearable and low-power sensors using the proposed EMEH platform.