LAUSR

In this letter, we establish a new type of passive ultrahigh-frequency (UHF) radio frequency identification (RFID) technology-based sensor with a referenced readout for moisture. We introduce the sensor system, which consists of a sensor tag and a reference tag. In a highly moist environment, the sensor tag, which is fabricated by embroidery and three-dimensional (3-D) printing, permanently changes its shape from flat to curved, which then influences its wireless performance. By recording the backscattered powers of the sensor tag and the unaffected reference tag, the presence of moisture could be detected. Based on our preliminary results, when the mean value of ΔP% was higher than 0.8, the sensor system indicated exposure to a high-moisture environment. Our moisture sensing system can provide cost-effective zero-energy monitoring of moisture exposure for versatile application fields.