Guangsheng Deng , Qiang Zhang , Yanbin Yu , Jun Yang , Ying Li , Wenbing Zhang , Zhiping Yin
{"title":"Microwave humidity sensor based on interdigital capacitors with compact size and enhanced sensitivity","authors":"Guangsheng Deng , Qiang Zhang , Yanbin Yu , Jun Yang , Ying Li , Wenbing Zhang , Zhiping Yin","doi":"10.1016/j.measurement.2025.119195","DOIUrl":null,"url":null,"abstract":"<div><div>This paper introduces a novel highly sensitive microwave humidity sensor based on a pair of planar split ring resonators, incorporating the intensive and localized resonance excited by the interdigital electrodes to detect relative humidity variation in the environment via spectroscopy analysis. A 0.25 mm thick replaceable polyimide (PI) film, whose relative permittivity is in close relate with the relative humidity of the environment, was covered on the interdigital electrodes and used as the moisture sensing material of the proposed sensor. Therefore, the resonance frequency of the sensor, which is highly sensitive to the relative permittivity of the PI film, varies with different humidities. The sensor experimentally demonstrated a high sensitivity of 2.02 MHz/%RH within a wide humidity monitoring range of 30–78 % RH, which significantly outperforms the reported microwave humidity sensors. Meanwhile, the sensor exhibits comparable hysteresis performance to commercial sensors during the testing cycles, which holds significant importance for practical applications. The proposed sensor, features a compact size with low cost and high sensitivity, provides a solution for precise humidity variation detecting from a spectrum measurement perspective.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119195"},"PeriodicalIF":5.6000,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Measurement","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0263224125025540","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
This paper introduces a novel highly sensitive microwave humidity sensor based on a pair of planar split ring resonators, incorporating the intensive and localized resonance excited by the interdigital electrodes to detect relative humidity variation in the environment via spectroscopy analysis. A 0.25 mm thick replaceable polyimide (PI) film, whose relative permittivity is in close relate with the relative humidity of the environment, was covered on the interdigital electrodes and used as the moisture sensing material of the proposed sensor. Therefore, the resonance frequency of the sensor, which is highly sensitive to the relative permittivity of the PI film, varies with different humidities. The sensor experimentally demonstrated a high sensitivity of 2.02 MHz/%RH within a wide humidity monitoring range of 30–78 % RH, which significantly outperforms the reported microwave humidity sensors. Meanwhile, the sensor exhibits comparable hysteresis performance to commercial sensors during the testing cycles, which holds significant importance for practical applications. The proposed sensor, features a compact size with low cost and high sensitivity, provides a solution for precise humidity variation detecting from a spectrum measurement perspective.
期刊介绍:
Contributions are invited on novel achievements in all fields of measurement and instrumentation science and technology. Authors are encouraged to submit novel material, whose ultimate goal is an advancement in the state of the art of: measurement and metrology fundamentals, sensors, measurement instruments, measurement and estimation techniques, measurement data processing and fusion algorithms, evaluation procedures and methodologies for plants and industrial processes, performance analysis of systems, processes and algorithms, mathematical models for measurement-oriented purposes, distributed measurement systems in a connected world.