Wireless-Powered VOCs Sensor Based on Energy-Harvesting Metamaterial

Abstract

Wireless-powered volatile organic compounds (VOCs) are designed by combining an energy-harvesting metamaterial (EH-MM) and ionic thermoplastic polyurethane (i-TPU) as a wireless sensing platform and VOCs sensing material within the microwave frequency, respectively. Using the multi-analyte sensing capability of an i-TPU film, the EH-MM sensor can distinguish different VOCs such as toluene, hexane, ethanol, and acetone, which cause harmful effects on the human body, by simply obtaining the corresponding output voltage levels without any complicated analysis system. The proposed EH-MM sensor also shows fast and immediate responses (<1 s), a wide range of VOCs concentrations (5-1000 ppm), and long-term stability (>1 month) under ambient conditions. Moreover, by harvesting commercially accessible WiFi energy, the proposed sensor does not require any battery but can be operated wirelessly, representing a novel method for designing real-time and battery-free sensors with a reliable performance.