{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T11:07:04Z","timestamp":1790075224217,"version":"4.0.1"},"reference-count":69,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T00:00:00Z","timestamp":1789948800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key R&D Program of China","doi-asserted-by":"publisher","award":["2022YFC2503900"],"award-info":[{"award-number":["2022YFC2503900"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Ministry of Science and Technology of China","id":[{"id":"https:\/\/ror.org\/02kv4zf79","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Sleep-related breathing disorders, particularly the obstructive sleep apnea syndrome, lead to an urgent demand for continuous, comfortable, and accurate monitoring technologies. However, conventional polysomnography is limited by complex procedures, poor wearing comfort, and restricted suitability for long-term monitoring. Owing to their skin-like mechanical performance, high biocompatibility, high ionic conductivity, and excellent tissue compatibility, hydrogels have emerged as promising materials for flexible bioelectronic devices. Recent multimodal hydrogel-based sensors enable simultaneous acquisition of mechanical, thermohygrometric, and electrophysiological signals, providing new opportunities for comprehensive sleep respiratory monitoring. This review systematically discusses the mechanisms for acquiring and analyzing multimodal physiological signals, including respiratory motion, respiratory airflow, auxiliary physiological signals, and AI-assisted sleep respiratory state recognition. Furthermore, structural design strategies, including single-layer, multilayer, biomimetic, and integrated architectures, are reviewed to clarify how structural configurations facilitate multimodal signal acquisition, signal interference suppression, and sensing performance optimization. This review provides valuable references for the future development of high-performance wearable multimodal hydrogel-based sensors toward sleep respiratory monitoring.<\/jats:p>","DOI":"10.3390\/s26185980","type":"journal-article","created":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T10:21:48Z","timestamp":1790072508000},"page":"5980","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Multimodal Hydrogel-Based Sensors for Sleep Respiratory Monitoring: Signal Sensing Mechanisms and Structural Design Strategies"],"prefix":"10.3390","volume":"26","author":[{"given":"Yuanfeng","family":"Sun","sequence":"first","affiliation":[{"name":"Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liangchao","family":"Li","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Sichuan University, Chengdu 610065, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuan","family":"Shi","sequence":"additional","affiliation":[{"name":"Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jian","family":"Jiao","sequence":"additional","affiliation":[{"name":"Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5534-333X","authenticated-orcid":false,"given":"Taomei","family":"Li","sequence":"additional","affiliation":[{"name":"Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiangdong","family":"Tang","sequence":"additional","affiliation":[{"name":"Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu 610041, China"},{"name":"Mental Health Center, West China Hospital, Sichuan University, Chengdu 610041, China"},{"name":"National Center for Mental Disorders, West China Hospital, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2820-7973","authenticated-orcid":false,"given":"Yihao","family":"Long","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Sichuan University, Chengdu 610065, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7402-9194","authenticated-orcid":false,"given":"Liang","family":"He","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Sichuan University, Chengdu 610065, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jingfei","family":"Xu","sequence":"additional","affiliation":[{"name":"Rehabilitation Medicine Center, West China Hospital, Sichuan University, Chengdu 610041, China"},{"name":"Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lan","family":"Zhang","sequence":"additional","affiliation":[{"name":"Mental Health Center, West China Hospital, Sichuan University, Chengdu 610041, China"},{"name":"National Center for Mental Disorders, West China Hospital, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1038\/s41392-023-01496-3","article-title":"Pathophysiological mechanisms and therapeutic approaches in obstructive sleep apnea syndrome","volume":"8","author":"Lv","year":"2023","journal-title":"Signal Transduct. 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