{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,20]],"date-time":"2026-02-20T02:47:55Z","timestamp":1771555675754,"version":"3.50.1"},"reference-count":22,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2022,8,22]],"date-time":"2022-08-22T00:00:00Z","timestamp":1661126400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"JSPS KAKENHI","award":["21K04076"],"award-info":[{"award-number":["21K04076"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Humidity measurement is required in various fields. We previously developed a sensor that leverages the sudden change in the transmitted light intensity when switching from leakage mode to waveguide mode. By adjusting the low-refractive-index polymer of the cladding, we achieved measurements at 60% RH. However, for practical use, measurements at low humidity are essential. Therefore, in this study, we developed a sensor using a leakage mode that enables measurements at low humidity. To measure the leakage mode, it is necessary to increase the absorbance of the cladding and the incident angle at the core\u2013cladding interface. Therefore, we developed a sensor in which the core was stretched, and the cladding was doped with a high concentration of dye. The experimental results confirmed that a sensor with a polymer concentration of 4% and a dye concentration of 3% could measure from 0% RH to 95% RH. The sensitivity was 0.1 dB\/% RH from 0% RH to 70% RH and 0.32 dB\/% RH from 70% RH to 95% RH. The estimated response time for a change from 10% to 90% light transmission for a sensor with 4% polymer concentration and 0.5% dye concentration was 22 s from 45% RH to 0% RH and 50 s from 0% RH to 45% RH.<\/jats:p>","DOI":"10.3390\/s22166315","type":"journal-article","created":{"date-parts":[[2022,8,22]],"date-time":"2022-08-22T23:49:56Z","timestamp":1661212196000},"page":"6315","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Improving Measurement Range of a Swellable Polymer-Clad Plastic Fiber Optic Humidity Sensor by Dye Addition"],"prefix":"10.3390","volume":"22","author":[{"given":"Yuta","family":"Shimura","sequence":"first","affiliation":[{"name":"Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Kofu 400-8510, Japan"}]},{"given":"Yutaka","family":"Suzuki","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Faculty of Science and Technology, Toyo University, Tokyo 112-8606, Japan"}]},{"given":"Masayuki","family":"Morisawa","sequence":"additional","affiliation":[{"name":"Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Kofu 400-8510, Japan"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1080\/02786826.2020.1829536","article-title":"The influence of temperature, humidity, and simulated sunlight on the infectivity of SARS-CoV-2 in aerosols","volume":"55","author":"Dabisch","year":"2021","journal-title":"Aerosol Sci. 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