Embroidered UHF RFID Moisture Sensor Tag on Dishcloth Substrate

摘要

In this paper, we present an embroidered passive UHF RFID moisture sensor tag made of dishcloth and conductive yarn. This extremely cost-effective and environmentally friendly wireless sensor can be easily embedded into versatile structures. The initial read range of the sensor tag was 4.7 meters at 915 MHz. In this preliminary study, 10 drops of water were applied on the sensor part of the structure and the performance of the sensor tag was measured in office conditions after 5, 10, and 15 minutes. After 5 minutes and 10 minutes, the read range increased to 5.0 and 5.2 meters, respectively, due to the conductivity improvement of the antenna pattern and increased backscattered power from the tag. After that, the sensor tag started to dry and the read range started to decrease. After 15 minutes, the read range was back to 4.7 meters at 915 MHz. Based on these initial results, these tags show potential for low-cost identification and sensing solutions.