{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T04:59:44Z","timestamp":1785301184011,"version":"3.55.0"},"reference-count":25,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T00:00:00Z","timestamp":1784851200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key Research and Development Project of China","award":["2023YFF0720900"],"award-info":[{"award-number":["2023YFF0720900"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>To address the need for bubble detection in industrial silicone sealing rings, this paper presents a compact non-invasive ultrasonic monitoring system based on a capacitive micromachined ultrasonic transducer (CMUT) array, aiming to overcome the limitations of conventional X-ray inspection in terms of safety, portability, and real-time in situ monitoring. The system comprises two 8.8 mm \u00d7 8.8 mm CMUT arrays with associated transmitting and receiving circuitry. The silicone thickness is determined using the time-of-flight (TOF) method, while bubble size is quantitatively estimated by combining received signal amplitude analysis, which characterizes bubble-induced attenuation, with correlation function evaluation. Experimental measurements on industrial-grade silicone samples and finite element simulations demonstrate that the system achieves a spatial resolution of 0.5 mm and effectively captures attenuation variations caused by bubbles. The integrated strategy of TOF, amplitude analysis, and correlation assessment ensures reliable non-destructive evaluation. Compared with X-ray inspection, the proposed system is safer, more portable, and suitable for real-time on-site monitoring, thereby significantly improving quality control efficiency in silicone manufacturing. This study provides a novel CMUT-array-based solution for quantitative bubble detection in silicone media, offering both high resolution and practical application potential.<\/jats:p>","DOI":"10.3390\/mi17080882","type":"journal-article","created":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T13:53:26Z","timestamp":1784901206000},"page":"882","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Safe and Portable CMUT Array Ultrasonic System for Bubble Sizing in Industrial Silicone Sealing Rings"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9897-1718","authenticated-orcid":false,"given":"Changde","family":"He","sequence":"first","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-3283-6438","authenticated-orcid":false,"given":"Shuo","family":"Liu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-0098-7050","authenticated-orcid":false,"given":"Hanchi","family":"Chai","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-6992-2529","authenticated-orcid":false,"given":"Dandan","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chengrui","family":"Liu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8187-7503","authenticated-orcid":false,"given":"Wanjia","family":"Gao","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuhua","family":"Yang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0968-6953","authenticated-orcid":false,"given":"Licheng","family":"Jia","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6879-8862","authenticated-orcid":false,"given":"Guojun","family":"Zhang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3441-9286","authenticated-orcid":false,"given":"Renxin","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6572-2045","authenticated-orcid":false,"given":"Jiangong","family":"Cui","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1762-9246","authenticated-orcid":false,"given":"Wendong","family":"Zhang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Extreme 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