Challenges in Development of Bended Passive UHF RFID Moisture Sensors on a Sponge Cloth

In this paper, we present fabrication and evaluation of embroidered passive UHF RFID moisture sensors on a bended sponge cloth. The sensors were firstly tested as flat, where moisture only affected the substrate properties, and as bended, where moisture also straightened the initially bended sensor tag. The sensor tags showed read ranges of 5 meters, and the flat sensors were found to be good indicators of moisture exposure. However, several challenges were encountered in sensor fabrication. Further, the main goals of the study, the bended sensors, showed very unstable performance. In this paper, we introduce the above-mentioned challenges.