Inkjet-Printed Humidity Sensor for Passive UHF RFID Systems

TLDR

Recent years have seen diverse humidity sensors for HF and UHF RFID systems, yet this paper reports one of the first passive UHF RFID humidity sensor tags fabricated with inkjet technology. The study introduces a novel inkjet‑printed humidity sensor tag for passive UHF RFID systems. The sensor tag’s structure and operating principle are detailed, and the paper outlines the practical method for performing humidity measurements. Measurement results demonstrate the tag’s humidity‑sensitivity characterization and its identification performance.

Abstract

This paper presents a novel inkjet-printed humidity sensor tag for passive radio-frequency identification (RFID) systems operating at ultrahigh frequencies (UHFs). During recent years, various humidity sensors have been developed by researchers around the world for HF and UHF RFID systems. However, to our best knowledge, the humidity sensor presented in this paper is one of the first passive UHF RFID humidity sensor tags fabricated using inkjet technology. This paper describes the structure and operation principle of the sensor tag as well as discusses the method of performing humidity measurements in practice. Furthermore, measurement results are presented, which include air humidity-sensitivity characterization and tag identification performance measurements.