{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,2]],"date-time":"2026-05-02T21:05:07Z","timestamp":1777755907925,"version":"3.51.4"},"reference-count":40,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2019,5,4]],"date-time":"2019-05-04T00:00:00Z","timestamp":1556928000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002920","name":"Research Grants Council, University Grants Committee","doi-asserted-by":"publisher","award":["15201416 and 15212417"],"award-info":[{"award-number":["15201416 and 15212417"]}],"id":[{"id":"10.13039\/501100002920","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51635008, 11772113 and 51875492"],"award-info":[{"award-number":["51635008, 11772113 and 51875492"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p> A new breed of nanocomposite-based spray-on sensor is developed for in-situ active structural health monitoring (SHM). The novel nanocomposite sensor is rigorously designed with graphene as the nanofiller and polyvinylpyrrolidone (PVP) as the matrix, fabricated using a simple spray deposition process. Electrical analysis, as well as morphological characterization of the spray-on sensor, was conducted to investigate percolation characteristic, in which the optimal threshold (~0.91%) of the graphene\/PVP sensor was determined. Owing to the uniform and stable conductive network formed by well-dispersed graphene nanosheets in the PVP matrix, the tailor-made spray-on sensor exhibited excellent piezoresistive performance. By virtue of the tunneling effect of the conductive network, the sensor was proven to be capable of perceiving signals of guided ultrasonic waves (GUWs) with ultrahigh frequency up to 500 kHz. Lightweight and flexible, the spray-on nanocomposite sensor demonstrated superior sensitivity, high fidelity, and high signal-to-noise ratio under dynamic strain with ultralow magnitude (of the order of micro-strain) that is comparable with commercial lead zirconate titanate (PZT) wafers. The sensors were further networked to perform damage characterization, and the results indicate significant application potential of the spray-on nanocomposite-based sensor for in-situ active GUW-based SHM.<\/jats:p>","DOI":"10.3390\/s19092077","type":"journal-article","created":{"date-parts":[[2019,5,9]],"date-time":"2019-05-09T11:22:35Z","timestamp":1557400955000},"page":"2077","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["A Spray-on, Nanocomposite-Based Sensor Network for in-Situ Active Structural Health Monitoring"],"prefix":"10.3390","volume":"19","author":[{"given":"Wuxiong","family":"Cao","sequence":"first","affiliation":[{"name":"School of Astronautics, Harbin Institute of Technology, Harbin 150080, China"},{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pengyu","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yaozhong","family":"Liao","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiongbin","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dongyue","family":"Pan","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yehai","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Baojun","family":"Pang","sequence":"additional","affiliation":[{"name":"School of Astronautics, Harbin Institute of Technology, Harbin 150080, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Li-min","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhongqing","family":"Su","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China"},{"name":"The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,5,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1177\/1475921708090566","article-title":"Damage identification of metallic structures using A0 mode of lamb waves","volume":"7","author":"Hu","year":"2008","journal-title":"Struct. 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