{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,22]],"date-time":"2026-01-22T16:47:01Z","timestamp":1769100421865,"version":"3.49.0"},"reference-count":32,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,3,6]],"date-time":"2023-03-06T00:00:00Z","timestamp":1678060800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea (NRF)","doi-asserted-by":"publisher","award":["2018R1A6A1A03026005"],"award-info":[{"award-number":["2018R1A6A1A03026005"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea (NRF)","doi-asserted-by":"publisher","award":["P0012744"],"award-info":[{"award-number":["P0012744"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003661","name":"Korea Institute for Advancement of Technology (KIAT)","doi-asserted-by":"publisher","award":["2018R1A6A1A03026005"],"award-info":[{"award-number":["2018R1A6A1A03026005"]}],"id":[{"id":"10.13039\/501100003661","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003661","name":"Korea Institute for Advancement of Technology (KIAT)","doi-asserted-by":"publisher","award":["P0012744"],"award-info":[{"award-number":["P0012744"]}],"id":[{"id":"10.13039\/501100003661","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We propose a sensor technology for detecting dew condensation, which exploits a variation in the relative refractive index on the dew-friendly surface of an optical waveguide. The dew-condensation sensor is composed of a laser, waveguide, medium (i.e., filling material for the waveguide), and photodiode. The formation of dewdrops on the waveguide surface causes local increases in the relative refractive index accompanied by the transmission of the incident light rays, hence reducing the light intensity inside the waveguide. In particular, the dew-friendly surface of the waveguide is obtained by filling the interior of the waveguide with liquid H2O, i.e., water. A geometric design for the sensor was first carried out considering the curvature of the waveguide and the incident angles of the light rays. Moreover, the optical suitability of waveguide media with various absolute refractive indices, i.e., water, air, oil, and glass, were evaluated through simulation tests. In actual experiments, the sensor with the water-filled waveguide displayed a wider gap between the measured photocurrent levels under conditions with and without dew, than those with the air- and glass-filled waveguides, as a result of the relatively high specific heat of the water. The sensor with the water-filled waveguide exhibited excellent accuracy and repeatability as well.<\/jats:p>","DOI":"10.3390\/s23052857","type":"journal-article","created":{"date-parts":[[2023,3,6]],"date-time":"2023-03-06T06:45:08Z","timestamp":1678085108000},"page":"2857","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["A Dew-Condensation Sensor Exploiting Local Variations in the Relative Refractive Index on the Dew-Friendly Surface of a Waveguide"],"prefix":"10.3390","volume":"23","author":[{"given":"Subin","family":"Hwa","sequence":"first","affiliation":[{"name":"Department of Creative Convergence Engineering, Hanbat National University, Daejeon 34158, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eun-Seon","family":"Sim","sequence":"additional","affiliation":[{"name":"Department of Creative Convergence Engineering, Hanbat National University, Daejeon 34158, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8336-9940","authenticated-orcid":false,"given":"Jun-Hee","family":"Na","sequence":"additional","affiliation":[{"name":"Department of Electrical, Electronics & Communication Engineering Education, Chungnam National University, Daejeon 34134, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ik-Hoon","family":"Jang","sequence":"additional","affiliation":[{"name":"FarmAI Lab, Jinong, Anyang-si 14067, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jin-Hyuk","family":"Kwon","sequence":"additional","affiliation":[{"name":"Research Institute of Printed Electronics & 3D Printing, Industry University Cooperation Foundation, Hanbat National University, Daejeon 34158, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6462-323X","authenticated-orcid":false,"given":"Min-Hoi","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Creative Convergence Engineering, Hanbat National University, Daejeon 34158, Republic of Korea"},{"name":"Research Institute of Printed Electronics & 3D Printing, Industry University Cooperation Foundation, Hanbat National University, Daejeon 34158, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1016\/j.compag.2010.08.005","article-title":"Sensing technologies for precision specialty crop production","volume":"74","author":"Lee","year":"2010","journal-title":"Comput. Electron. Agric."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1094\/PDIS-03-15-0340-FE","article-title":"Plant disease detection by imaging sensors\u2013parallels and specific demands for precision agriculture and plant phenotyping","volume":"100","author":"Mahlein","year":"2016","journal-title":"Plant Dis."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1149\/2.F05104if","article-title":"Sensors for agriculture and the food industry","volume":"19","author":"Li","year":"2010","journal-title":"Electrochem. Soc. Interface"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1007\/s10311-009-0228-8","article-title":"Nanotechnology applications in pollution sensing and degradation in agriculture: A review","volume":"7","author":"Baruah","year":"2009","journal-title":"Environ. Chem. Lett."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3758","DOI":"10.1109\/JIOT.2018.2844296","article-title":"An overview of Internet of Things (IoT) and data analytics in agriculture: Benefits and challenges","volume":"5","author":"Elijah","year":"2018","journal-title":"IEEE Internet Things J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.agwat.2015.01.020","article-title":"UAVs challenge to assess water stress for sustainable agriculture","volume":"153","author":"Gago","year":"2015","journal-title":"Agric. Water Manag."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.biosystemseng.2016.04.010","article-title":"Field phenotyping system for the assessment of potato late blight resistance using RGB imagery from an unmanned aerial vehicle","volume":"148","author":"Sugiura","year":"2016","journal-title":"Biosyst. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1810","DOI":"10.1039\/b906634a","article-title":"Soil macronutrient sensing for precision agriculture","volume":"11","author":"Kim","year":"2009","journal-title":"J. Environ. Monit."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2875","DOI":"10.1016\/j.rse.2010.07.005","article-title":"Monitoring agricultural drought for arid and humid regions using multi-sensor remote sensing data","volume":"114","author":"Rhee","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"291","DOI":"10.2136\/sssaj1991.03615995005500010052x","article-title":"Probe for measuring soil specific heat using a heat-pulse method","volume":"55","author":"Campbell","year":"1991","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1016\/S0038-092X(96)00130-2","article-title":"Dehydration of food crops using a solar dryer with convective heat flow","volume":"59","author":"Ayensu","year":"1997","journal-title":"Sol. Energy"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3640","DOI":"10.3390\/s110403640","article-title":"Wireless sensor network-based greenhouse environment monitoring and automatic control system for dew condensation prevention","volume":"11","author":"Park","year":"2011","journal-title":"Sensors"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2295","DOI":"10.1007\/s10765-010-0877-7","article-title":"Thermophysical properties of plant leaves and their influence on the environment temperature","volume":"31","author":"Jayalakshmy","year":"2010","journal-title":"Int. J. Thermophys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"572","DOI":"10.1016\/j.jaridenv.2005.09.004","article-title":"Dew formation and water vapor adsorption in semi-arid environments\u2014A review","volume":"65","author":"Agam","year":"2006","journal-title":"J. Arid. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/0002-1571(66)90008-2","article-title":"Studies on dew formation under semi-arid conditions","volume":"3","author":"Baier","year":"1966","journal-title":"Agric. Meteorol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"572","DOI":"10.1175\/1520-0477-42.8.572","article-title":"The contribution of dew to the summer water budget of northern Idaho","volume":"42","author":"Lloyd","year":"1961","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1016\/0002-1571(81)90081-9","article-title":"Estimating dew duration. I. Utilizing micrometeorological data","volume":"25","author":"Pedro","year":"1981","journal-title":"Agric. Meteorol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"7881","DOI":"10.3390\/s140507881","article-title":"Humidity sensors principle, mechanism, and fabrication technologies: A comprehensive review","volume":"14","author":"Farahani","year":"2014","journal-title":"Sensors"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"274","DOI":"10.1166\/sl.2005.045","article-title":"Humidity sensors: A review of materials and mechanisms","volume":"3","author":"Chen","year":"2005","journal-title":"Sens. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/S0924-4247(01)00788-9","article-title":"Recent achievements in miniaturised humidity sensors\u2014A review of transduction techniques","volume":"96","author":"Rittersma","year":"2002","journal-title":"Sens. Actuators A Phys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2010","DOI":"10.1002\/(SICI)1097-4628(19991121)74:8<2010::AID-APP16>3.0.CO;2-1","article-title":"A novel resistive-type humidity sensor based on poly (p-diethynylbenzene)","volume":"74","author":"Yang","year":"1999","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2017","DOI":"10.1007\/s00542-010-1139-0","article-title":"High-performance capacitive humidity sensor with novel electrode and polyimide layer based on MEMS technology","volume":"16","author":"Kim","year":"2010","journal-title":"Microsyst. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/0250-6874(85)87002-5","article-title":"Theoretical studies on the impedance-humidity characteristics of ceramic humidity sensors","volume":"7","author":"Shimizu","year":"1985","journal-title":"Sens. Actuators"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"15313","DOI":"10.1364\/OE.25.015313","article-title":"Fiber optic humidity sensor using water vapor condensation","volume":"25","author":"Limodehi","year":"2017","journal-title":"Opt. Express"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.yofte.2018.01.006","article-title":"Multi-channel fiber optic dew and humidity sensor","volume":"41","author":"Limodehi","year":"2018","journal-title":"Opt. Fiber Technol."},{"key":"ref_26","first-page":"272","article-title":"Extending the range of a fibre-optic relative-humidity","volume":"38\u201339","author":"Brook","year":"1997","journal-title":"Sensor"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"725","DOI":"10.1109\/LPT.2022.3181756","article-title":"Advanced fiber-optic relative humidity sensor based on graphene quantum dots doped polyimide coating","volume":"34","author":"Hou","year":"2022","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"105732","DOI":"10.1016\/j.rinp.2022.105732","article-title":"Optical sensing based on classical analogy of double Electromagnetically induced transparencies","volume":"39","author":"Huang","year":"2022","journal-title":"Results Phys."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"054064","DOI":"10.1103\/PhysRevApplied.13.054064","article-title":"Excitation of Bloch Surface Waves in Zero-Admittance Multilayers for High-Sensitivity Sensor Applications","volume":"13","author":"Niu","year":"2020","journal-title":"Phys. Rev. Appl."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"415","DOI":"10.46670\/JSST.2021.30.6.415","article-title":"Refractive index-based soil moisture sensor","volume":"30","author":"Sim","year":"2021","journal-title":"J. Sens. Sci. Technol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"253108","DOI":"10.1063\/1.4905133","article-title":"Anomalous decrease of the specific heat capacity at the electrical and thermal conductivity percolation threshold in nanocomposites","volume":"105","author":"Kim","year":"2014","journal-title":"Appl. Phys. Lett."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"5927","DOI":"10.1039\/C4AN01300J","article-title":"Karhunen-Lo\u00e8ve treatment to remove noise and facilitate data analysis in sensing, spectroscopy and other applications","volume":"139","author":"Zaharov","year":"2014","journal-title":"Analyst"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/5\/2857\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:48:58Z","timestamp":1760122138000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/5\/2857"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,3,6]]},"references-count":32,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2023,3]]}},"alternative-id":["s23052857"],"URL":"https:\/\/doi.org\/10.3390\/s23052857","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,3,6]]}}}