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Maintenance-free moisture sensor on dishcloth substrate

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Details

Original languageEnglish
Title of host publication2019 Photonics and Electromagnetics Research Symposium - Fall, PIERS - Fall 2019 - Proceedings
PublisherIEEE
Pages2418-2421
Number of pages4
ISBN (Electronic)9781728153049
DOIs
Publication statusPublished - 1 Dec 2019
Publication typeA4 Article in a conference publication
Event2019 Photonics and Electromagnetics Research Symposium - Fall, PIERS - Fall 2019 - Xiamen, China
Duration: 17 Dec 201920 Dec 2019

Conference

Conference2019 Photonics and Electromagnetics Research Symposium - Fall, PIERS - Fall 2019
CountryChina
CityXiamen
Period17/12/1920/12/19

Abstract

In this study, a passive UHF RFID-based moisture sensor is fabricated and evaluated. The sensor tag can sense the high humidity of the environment and indicate it with a permanent change in its backscattered signal. The sensor tag antenna and antenna-IC interconnections are fabricated on a biodegradable dishcloth material using conductive thread. The sensors are tested in an anechoic chamber and in normal office conditions, when initially dry, after dipped into water for 1 minute, and again after 24 hours of drying in air. These sensor tags initially show read ranges of 6-9 meters throughout the global UHF RFID frequency band. When wet, the read range decreases to 5 meters, while after 24 hours of drying, the read ranges of the tags permanently decrease to around 2-4 meters. The dishcloth material comes thicker when wet, also causing a change to the embroidered antenna structure, finally causing the permanent change in the backscattered signal. In normal office conditions, moisture causes the average backscattered signal an obvious change from around -66 dBm to -69 dBm.