{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T18:40:34Z","timestamp":1768588834382,"version":"3.49.0"},"reference-count":33,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2020,6,19]],"date-time":"2020-06-19T00:00:00Z","timestamp":1592524800000},"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>A technique and electronic circuit for contactless electromagnetic interrogation of piezoelectric micro-electromechanical system (MEMS) resonator sensors are proposed. The adopted resonator is an aluminum-nitride (AlN) thin-film piezoelectric-on-silicon (TPoS) disk vibrating in radial contour mode at about 6.3 MHz. The MEMS resonator is operated in one-port configuration and it is connected to a spiral coil, forming the sensor unit. A proximate electronic interrogation unit is electromagnetically coupled through a readout coil to the sensor unit. The proposed technique exploits interleaved excitation and detection phases of the MEMS resonator. A tailored electronic circuit manages the periodic switching between the excitation phase, where it generates the excitation signal driving the readout coil, and the detection phase, where it senses the transient decaying response of the resonator by measuring through a high-impedance amplifier the voltage induced back across the readout coil. This approach advantageously ensures that the readout frequency of the MEMS resonator is first order independent of the interrogation distance between the readout and sensor coils. The reported experimental results show successful contactless readout of the MEMS resonator independently from the interrogation distance over a range of 12 mm, and the application as a resonant sensor for ambient temperature and as a resonant acoustic-load sensor to detect and track the deposition and evaporation processes of water microdroplets on the MEMS resonator surface.<\/jats:p>","DOI":"10.3390\/s20123483","type":"journal-article","created":{"date-parts":[[2020,6,19]],"date-time":"2020-06-19T12:19:55Z","timestamp":1592569195000},"page":"3483","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Technique and Circuit for Contactless Readout of Piezoelectric MEMS Resonator Sensors"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5696-4138","authenticated-orcid":false,"given":"Marco","family":"Ba\u00f9","sequence":"first","affiliation":[{"name":"Department of Information Engineering, University of Brescia, via Branze 38, I25123 Brescia, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3310-7715","authenticated-orcid":false,"given":"Marco","family":"Ferrari","sequence":"additional","affiliation":[{"name":"Department of Information Engineering, University of Brescia, via Branze 38, I25123 Brescia, Italy"},{"name":"INO-CNR, via Branze 45, I25123 Brescia, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7211-6139","authenticated-orcid":false,"given":"Habiba","family":"Begum","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong, China"}]},{"given":"Abid","family":"Ali","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1741-1485","authenticated-orcid":false,"given":"Joshua E.-Y.","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong, China"},{"name":"State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Kowloon, Hong Kong, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3949-9975","authenticated-orcid":false,"given":"Vittorio","family":"Ferrari","sequence":"additional","affiliation":[{"name":"Department of Information Engineering, University of Brescia, via Branze 38, I25123 Brescia, Italy"},{"name":"INO-CNR, via Branze 45, I25123 Brescia, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2020,6,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"013001","DOI":"10.1088\/0960-1317\/22\/1\/013001","article-title":"A review of MEMS oscillators for frequency reference and timing applications","volume":"22","author":"Puers","year":"2012","journal-title":"J. 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