{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T21:53:59Z","timestamp":1769723639034,"version":"3.49.0"},"reference-count":20,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2021,11,20]],"date-time":"2021-11-20T00:00:00Z","timestamp":1637366400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Developing technologies capable of constantly assessing and optimizing day-to-day activities has been a research priority for several years. A key factor in such technologies is the use of highly sensitive sensors to monitor in real-time numerous parameters, such as temperature and load. Due to their unique features, optical fiber sensors became one of the most interesting and viable solutions for applications dependent on those parameters. In this work, we present an optical fiber load sensor, called load cell, based on Fabry\u2013P\u00e9rot hollow cavities embedded in a polymeric material. By using the load cells in a parallel configuration with a non-embedded hollow cavity, the optical Vernier effect was generated, allowing maximum sensitivity values of 0.433 nm N\u22121 and 0.66 nm \u00b0C\u22121 to be attained for vertical load and temperature, respectively. The proposed sensor\u2019s performance, allied with the proposed configuration, makes it a viable and suitable device for a wide range of applications, namely those requiring high thermal and load sensitivities.<\/jats:p>","DOI":"10.3390\/s21227737","type":"journal-article","created":{"date-parts":[[2021,11,21]],"date-time":"2021-11-21T21:00:50Z","timestamp":1637528450000},"page":"7737","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Fiber Optic Load Cells with Enhanced Sensitivity by Optical Vernier Effect"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0736-5849","authenticated-orcid":false,"given":"Tiago","family":"Paix\u00e3o","sequence":"first","affiliation":[{"name":"I3N and Physics Department, Campus of Santiago, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Ricardo","family":"Ferreira","sequence":"additional","affiliation":[{"name":"I3N and Physics Department, Campus of Santiago, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9958-0409","authenticated-orcid":false,"given":"M. F\u00e1tima","family":"Domingues","sequence":"additional","affiliation":[{"name":"IT\u2014Instituto de Telecomunica\u00e7\u00f5es, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9129-3539","authenticated-orcid":false,"given":"Paulo","family":"Antunes","sequence":"additional","affiliation":[{"name":"I3N and Physics Department, Campus of Santiago, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"IT\u2014Instituto de Telecomunica\u00e7\u00f5es, University of Aveiro, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"013002","DOI":"10.1088\/0964-1726\/20\/1\/013002","article-title":"Polymer optical fiber sensors\u2014A review","volume":"20","author":"Peters","year":"2011","journal-title":"Smart Mater. Struct."},{"key":"ref_2","unstructured":"Yin, S., Ruffin, P.B., and Yu, F.T.S. (2008). Fiber Optic Sensors, CRC Press\u2014Taylor & Francis Group."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Gomes, A.D., Becker, M., Dellith, J., Zibaii, M.I., Latifi, H., Rothhardt, M., Bartelt, H., and Fraz\u00e3o, O. (2019). Multimode Fabry\u2013Perot Interferometer Probe Based on Vernier Effect for Enhanced Temperature Sensing. Sensors, 19.","DOI":"10.3390\/s19030453"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"4833","DOI":"10.1364\/OL.44.004833","article-title":"Highly sensitive fiber optic temperature and strain sensor based on an intrinsic Fabry\u2013Perot interferometer fabricated by a femtosecond laser","volume":"44","author":"Antunes","year":"2019","journal-title":"Opt. Lett."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"106520","DOI":"10.1016\/j.optlastec.2020.106520","article-title":"Hybrid intrinsic optical fiber sensor fabricated by femtosecond laser with enhanced sensitivity by Vernier effect","volume":"133","author":"Ferreira","year":"2021","journal-title":"Opt. Laser Technol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"19581","DOI":"10.1364\/OE.22.019581","article-title":"Cascaded fiber-optic Fabry-Perot interferometers with Vernier effect for highly sensitive measurement of axial strain and magnetic field","volume":"22","author":"Zhang","year":"2014","journal-title":"Opt. Express"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"6662","DOI":"10.1364\/OE.23.006662","article-title":"Highly sensitive refractive index sensor based on cascaded microfiber knots with Vernier effect","volume":"23","author":"Xu","year":"2015","journal-title":"Opt. Express"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"125291","DOI":"10.1016\/j.optcom.2020.125291","article-title":"Sensitivity amplification of bubble-based all-silica fiber liquid-pressure sensor by using femtosecond laser exposure","volume":"462","author":"Zhang","year":"2020","journal-title":"Opt. Commun."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"19313","DOI":"10.1038\/s41598-020-76324-7","article-title":"Giant refractometric sensitivity by combining extreme optical Vernier effect and modal interference","volume":"10","author":"Gomes","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"109866","DOI":"10.1109\/ACCESS.2020.3001091","article-title":"Wearable Devices for Remote Physical Rehabilitation Using a Fabry-Perot Optical Fiber Sensor: Ankle Joint Kinematic","volume":"8","author":"Domingues","year":"2020","journal-title":"IEEE Access"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1016\/j.measurement.2015.07.031","article-title":"Cost effective refractive index sensor based on optical fiber micro cavities produced by the catastrophic fuse effect","volume":"77","author":"Domingues","year":"2016","journal-title":"Measurement"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1109\/LPT.2013.2288930","article-title":"Optical Fiber Microcavity Strain Sensors Produced by the Catastrophic Fuse Effect","volume":"26","author":"Antunes","year":"2014","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Gomes, A.D., Bartelt, H., and Fraz\u00e3o, O. (2021). Optical Vernier Effect: Recent Advances and Developments. Laser Photon. Rev., 15.","DOI":"10.1002\/lpor.202000588"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"108451","DOI":"10.1016\/j.measurement.2020.108451","article-title":"Fiber-optic sensors based on Vernier effect","volume":"167","author":"Liu","year":"2021","journal-title":"Meas. J. Int. Meas. Confed."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2121","DOI":"10.1364\/OL.39.002121","article-title":"High-sensitivity strain sensor based on in-fiber improved Fabry-Perot interferometer","volume":"39","author":"Liu","year":"2014","journal-title":"Opt. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"4145","DOI":"10.1364\/OE.384815","article-title":"Ultrasensitive refractive index sensor based on enhanced Vernier effect through cascaded fiber core-offset pairs","volume":"28","author":"Li","year":"2020","journal-title":"Opt. Express"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"120297","DOI":"10.1109\/ACCESS.2019.2933561","article-title":"A Transverse Load Sensor with Ultra-Sensitivity Employing Vernier-Effect Improved Parallel-Structured Fiber-Optic Fabry-Perot Interferometer","volume":"7","author":"Wu","year":"2019","journal-title":"IEEE Access"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"102163","DOI":"10.1016\/j.yofte.2020.102163","article-title":"Temperature insensitive fiber Fabry-Perot\/Mach-Zehnder hybrid interferometer based on photonic crystal fiber for transverse load and refractive index measurement","volume":"56","author":"Wang","year":"2020","journal-title":"Opt. Fiber Technol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"21946","DOI":"10.1364\/OE.20.021946","article-title":"Towards the control of highly sensitive Fabry-P\u00e9rot strain sensor based on hollow-core ring photonic crystal fiber","volume":"20","author":"Ferreira","year":"2012","journal-title":"Opt. Express"},{"key":"ref_20","first-page":"1","article-title":"Modified All-Fiber Fabry\u2013Perot Interferometer and Its Refractive Index, Load, and Temperature Analyses","volume":"7","year":"2015","journal-title":"IEEE Photonics J."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/22\/7737\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:33:20Z","timestamp":1760168000000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/22\/7737"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,11,20]]},"references-count":20,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2021,11]]}},"alternative-id":["s21227737"],"URL":"https:\/\/doi.org\/10.3390\/s21227737","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,11,20]]}}}