{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T09:40:33Z","timestamp":1774518033576,"version":"3.50.1"},"reference-count":51,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2021,11,9]],"date-time":"2021-11-09T00:00:00Z","timestamp":1636416000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Youth Talents Foundation of Research Center of Laser Fusion CAEP","award":["RCFCZ5-2021-3"],"award-info":[{"award-number":["RCFCZ5-2021-3"]}]},{"name":"The National Natural Science Foundation of China","award":["12174355"],"award-info":[{"award-number":["12174355"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Stretchable optical fiber sensors (SOFSs), which are promising and ultra-sensitive next-generation sensors, have achieved prominent success in applications including health monitoring, robotics, and biological\u2013electronic interfaces. Here, we report an ultra-sensitive multi-functional optical micro\/nanofiber embedded with a flexible polydimethylsiloxane (PDMS) membrane, which is compatible with wearable optical sensors. Based on the effect of a strong evanescent field, the as-fabricated SOFS is highly sensitive to strain, achieving high sensitivity with a peak gauge factor of 450. In addition, considering the large negative thermo-optic coefficient of PDMS, temperature measurements in the range of 30 to 60 \u00b0C were realized, resulting in a 0.02 dBm\/\u00b0C response. In addition, wide-range detection of humidity was demonstrated by a peak sensitivity of 0.5 dB\/% RH, with less than 10% variation at each humidity stage. The robust sensing performance, together with the flexibility, enables the real-time monitoring of pulse, body temperature, and respiration. This as-fabricated SOFS provides significant potential for the practical application of wearable healthcare sensors.<\/jats:p>","DOI":"10.3390\/s21227437","type":"journal-article","created":{"date-parts":[[2021,11,9]],"date-time":"2021-11-09T21:39:07Z","timestamp":1636493947000},"page":"7437","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["An Ultra-Sensitive Multi-Functional Optical Micro\/Nanofiber Based on Stretchable Encapsulation"],"prefix":"10.3390","volume":"21","author":[{"given":"Siheng","family":"Xiang","sequence":"first","affiliation":[{"name":"Department of Engineering Optics, Research Center of Laser Fusion CAEP, Mianyang 621900, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hui","family":"You","sequence":"additional","affiliation":[{"name":"Department of Engineering Optics, Research Center of Laser Fusion CAEP, Mianyang 621900, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xinxiang","family":"Miao","sequence":"additional","affiliation":[{"name":"Department of Engineering Optics, Research Center of Laser Fusion CAEP, Mianyang 621900, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Longfei","family":"Niu","sequence":"additional","affiliation":[{"name":"Department of Engineering Optics, Research Center of Laser Fusion CAEP, Mianyang 621900, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0769-7624","authenticated-orcid":false,"given":"Caizhen","family":"Yao","sequence":"additional","affiliation":[{"name":"Department of Engineering Optics, Research Center of Laser Fusion CAEP, Mianyang 621900, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yilan","family":"Jiang","sequence":"additional","affiliation":[{"name":"Department of Engineering Optics, Research Center of Laser Fusion CAEP, Mianyang 621900, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Guorui","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Engineering Optics, Research Center of Laser Fusion CAEP, Mianyang 621900, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5310","DOI":"10.1002\/adma.201400633","article-title":"Fiber-based wearable electronics: A review of materials, fabrication, devices, and applications","volume":"26","author":"Wei","year":"2014","journal-title":"Adv. Mater."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1016\/j.nantod.2016.08.010","article-title":"Wearable fiber-shaped energy conversion and storage devices based on aligned carbon nanotubes","volume":"11","author":"Lv","year":"2016","journal-title":"Nano Today"},{"key":"ref_3","first-page":"5","article-title":"Polymer memory devices: Control of resistive switching voltage by nanoparticle-Decorated wrinkle interface","volume":"5","author":"Mao","year":"2019","journal-title":"Adv. Electron. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"10776","DOI":"10.1039\/c4ta00203b","article-title":"Textile energy storage in perspective","volume":"2","author":"Jost","year":"2014","journal-title":"J. Mater. Chem. A."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1177\/0040517513494253","article-title":"Stretch sensing properties of knitted structures made of PEDOT-coated conductive viscose and polyester yarns","volume":"84","author":"Bashir","year":"2014","journal-title":"Text. Res. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"42255","DOI":"10.1002\/app.42255","article-title":"Electrically conductive polymeric bi-component fibers containing a high load of low-structured carbon black","volume":"132","author":"Nilsson","year":"2015","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.compscitech.2013.08.006","article-title":"Electroactive bio-composite actuators based on cellulose acetate nanofibers with specially chopped polyaniline nanoparticles through electrospinning","volume":"87","author":"Hong","year":"2013","journal-title":"Compos. Sci. Technol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1383","DOI":"10.1002\/mame.201600234","article-title":"Durable, washable, and flexible conductive PET fabrics designed by fiber interfacial molecular engineering","volume":"301","author":"Liu","year":"2016","journal-title":"Macromol. Mater. Eng."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"16815","DOI":"10.1039\/C8RA02567C","article-title":"Graphene-based surface heater for de-icing applications","volume":"8","author":"Karim","year":"2018","journal-title":"RSC Adv."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"9591","DOI":"10.1007\/s10853-019-03519-3","article-title":"Electrically conductive highly elastic polyamide\/lycra fabric treated with PEDOT:PSS and polyurethane","volume":"54","author":"Tadesse","year":"2019","journal-title":"J. Mater. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"8423","DOI":"10.1109\/JSEN.2020.2982742","article-title":"Effect of multi-walled carbon nanotubes on analytical parameters of laccase-based biosensors received by soft plasma polymerization technique","volume":"20","author":"Szymon","year":"2020","journal-title":"IEEE Sens. J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"859","DOI":"10.1038\/nmat2834","article-title":"Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers","volume":"9","author":"Mannsfeld","year":"2010","journal-title":"Nat. Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1570","DOI":"10.1039\/C8NR08589G","article-title":"An ultra-stretchable, highly sensitive and biocompatible capacitive strain sensor from an ionic nanocomposite for on-skin monitoring","volume":"11","author":"Xu","year":"2019","journal-title":"Nanoscale"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"5845","DOI":"10.1039\/C7TC01169E","article-title":"Resistive electronic skin","volume":"5","author":"Jason","year":"2017","journal-title":"J. Mater. Chem. C"},{"key":"ref_15","first-page":"575","article-title":"Fabrication of metal nanowire based stretchable mesh electrode for wearable heater application","volume":"14","author":"Kim","year":"2018","journal-title":"Small"},{"key":"ref_16","first-page":"1940","article-title":"Self-powered and self-functional cotton sock using piezoelectric and triboelectric hybrid mechanism for healthcare and sports monitoring","volume":"13","author":"Zhu","year":"2019","journal-title":"ACS Nano"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"15855","DOI":"10.1021\/acsami.8b02564","article-title":"Piezoelectric polyacrylonitrile nanofiber film-based dual-function self-powered flexible sensor","volume":"10","author":"Zhao","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3964","DOI":"10.1021\/acsnano.8b01557","article-title":"Skin-inspired hierarchical polymer architectures with gradient stiffness for spacer-free, ultrathin, and highly sensitive triboelectric sensors","volume":"12","author":"Ha","year":"2018","journal-title":"ACS Nano"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1800703","DOI":"10.1002\/admt.201800703","article-title":"Fabrication of large-area bimodal sensors by all-inkjet-printing","volume":"4","author":"Wu","year":"2019","journal-title":"Adv. Mater. Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"728","DOI":"10.1109\/5.867687","article-title":"Rationale and challenges for optical interconnects to electronic chips","volume":"88","author":"Miller","year":"2000","journal-title":"Proc. IEEE"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"899","DOI":"10.1038\/nmat3711","article-title":"User-interactive electronic skin for instantaneous pressure visualization","volume":"12","author":"Wang","year":"2013","journal-title":"Nat. Mater."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"10244","DOI":"10.1002\/adma.201603160","article-title":"Highly stretchable, strain sensing hydrogel optical fibers","volume":"28","author":"Guo","year":"2016","journal-title":"Adv. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"12939","DOI":"10.1364\/OE.26.012939","article-title":"Strain, temperature, moisture, and transverse force sensing using fused polymer optical fibers","volume":"26","author":"Frizera","year":"2018","journal-title":"Opt. Express"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1007\/s00779-010-0303-y","article-title":"Fiber optic sensors for wearable applications","volume":"15","author":"Rantala","year":"2011","journal-title":"Pers. Ubiquitous Comput."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"71020","DOI":"10.1109\/ACCESS.2018.2881463","article-title":"A transparent strain sensor based on PDMS-embedded conductive fabric for wearable sensing applications","volume":"4","author":"Nag","year":"2018","journal-title":"IEEE Access"},{"key":"ref_26","unstructured":"Optical Society of America (2017). In a First for Wearable Optics, Researchers Develop Stretchy Fiber to Capture Body Motion, Optical Society of America."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Tong, L. (2018). Micro\/Nanofibre optical sensors: Challenges and prospects. Sensors, 18.","DOI":"10.3390\/s18030903"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Wu, Y., Yao, B., Yu, C., and Rao, Y. (2018). Optical graphene gas sensors based on microfibers: A review. Sensors, 18.","DOI":"10.3390\/s18040941"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"3578","DOI":"10.1364\/OE.22.003578","article-title":"Highly sensitive force sensor based on optical microfiber asymmetrical fabry-perot interferometer","volume":"22","author":"Gong","year":"2014","journal-title":"Opt. Express"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"5631","DOI":"10.1016\/j.ijleo.2016.03.082","article-title":"Locally pressed etched optical fiber with PDMS coating for a sensor application","volume":"127","author":"Kacik","year":"2016","journal-title":"Optik"},{"key":"ref_31","first-page":"126","article-title":"Surface plasmon resonance-based optical fiber embedded in PDMS for temperature sensing","volume":"12","year":"2017","journal-title":"IEEE J. Sel. Top. Quantum Electron."},{"key":"ref_32","first-page":"77500","article-title":"Chemical sensor using polymer coated tapered optical fibers","volume":"7750","author":"Dai","year":"2010","journal-title":"Int. Soc. Opt. Photonics"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Wang, D., Sheng, B., Peng, L., Huang, Y., and Ni, Z. (2019). Flexible and optical fiber sensors composited by graphene and pdms for motion detection. Polymers, 11.","DOI":"10.3390\/polym11091433"},{"key":"ref_34","unstructured":"Zhao, C., Hou, L., Xu, B., Chen, H., and Wang, D. (2018, January 16\u201319). High-sensitivity hydraulic pressure sensor realized with PDMS film-based Fabry-Perot interferometer. Proceedings of the 17th International Conference on Optical Communications and Networks, Zhuhai, China."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1364\/OPEX.12.001025","article-title":"Single-mode guiding properties of subwavelength-diameter silica and silicon wire waveguides","volume":"12","author":"Tong","year":"2004","journal-title":"Opt. Express"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.mssp.2018.03.022","article-title":"Heterogeneous SnO2\/ZnO nanoparticulate film: Facile synthesis and humidity sensing capability","volume":"81","author":"Ismail","year":"2018","journal-title":"Mater. Sci. Semicond. Process."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1016\/j.matlet.2017.09.040","article-title":"Enhanced humidity sensing performance using Sn-Doped ZnO nanorod Array\/SnO2 nanowire heteronetwork fabricated via two-step solution immersion","volume":"210","author":"Ismail","year":"2018","journal-title":"Mater. Lett."},{"key":"ref_38","unstructured":"Lin, C., He, J., Jiang, S., Liu, X., Zhao, D., and Zhang, D. (November, January 29). Humidity sensing characteristics of tin oxide thin film gas sensors varying with the operating voltage. Proceedings of the IEEE 11th International Conference on Solid-State and Integrated Circuit Technology, Xian, China."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"91","DOI":"10.4028\/www.scientific.net\/JNanoR.4.91","article-title":"Synthesis and characterization of tin oxide nanoparticle for humidity sensor applications","volume":"4","author":"Krishnakumar","year":"2008","journal-title":"J. Nano Res."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.snb.2018.10.054","article-title":"Humic acid nanosheets decorated by tin oxide nanoparticles and there humidity sensing behavior","volume":"280","author":"Duraia","year":"2019","journal-title":"Sens. Actuators"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.snb.2016.04.045","article-title":"High sensitivity humidity sensor based on cladding-etched optical fiber and lossy mode resonances","volume":"233","author":"Ascorbe","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_42","first-page":"3466","article-title":"Conductive core-shell aramid nanofibrils: Compromising conductivity with mechanical robustness for organic wearable sensing","volume":"11","author":"Xiang","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"4463","DOI":"10.1021\/am509087u","article-title":"Highly stretchable and sensitive unidirectional strain sensor via laser carbonization","volume":"7","author":"Rahimi","year":"2015","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"25563","DOI":"10.1021\/acsami.6b09188","article-title":"Ultrasensitive cracking-assisted strain sensors based on silver nanowires\/graphene hybrid particles","volume":"8","author":"Chen","year":"2016","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1905527","DOI":"10.1002\/adma.201905527","article-title":"Sensitive wearable temperature sensor with seamless monolithic integration","volume":"32","author":"Shin","year":"2020","journal-title":"Adv. Mater."},{"key":"ref_46","first-page":"366","article-title":"Solution-processed tin oxide-pedot:pss interconnecting layers for efficient inverted and conventional tandem polymer solar cells","volume":"3","author":"Rasi","year":"2019","journal-title":"Sol. RRL"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1040","DOI":"10.3788\/co.20191205.1040","article-title":"Perovskite solar cells based on a spray-coating tin oxide film","volume":"12","author":"Wang","year":"2019","journal-title":"Chin. Opt."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"085220","DOI":"10.1063\/1.5104333","article-title":"Fluorine doped tin oxide as an alternative of indium tin oxide for bottom electrode of semi-transparent organic photovoltaic devices","volume":"9","author":"Way","year":"2019","journal-title":"AIP Adv."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1016\/j.snb.2010.03.049","article-title":"A humidity sensor based on a hetero-core optical fiber","volume":"147","author":"Akita","year":"2010","journal-title":"Sens. Actuators B Chem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.sna.2012.10.041","article-title":"Novel optical fiber humidity sensor based on a no-core fiber structure","volume":"190","author":"Xia","year":"2013","journal-title":"Sens. Actuator A Phys."},{"key":"ref_51","unstructured":"Shuai, L., Meng, H., Rui, X., Deng, S., Wang, X., Jiao, T., Tan, C., and Huang, X. (2017, January 7\u201310). Humidity sensor based on core-offset fiber mach-zehnder interferometer coated graphene oxide film. Proceedings of the 2017 16th International Conference on Optical Communications and Networks (ICOCN), Wuzhen, China."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/22\/7437\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:28:04Z","timestamp":1760167684000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/22\/7437"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,11,9]]},"references-count":51,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2021,11]]}},"alternative-id":["s21227437"],"URL":"https:\/\/doi.org\/10.3390\/s21227437","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,11,9]]}}}