{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T06:45:31Z","timestamp":1782801931418,"version":"3.54.5"},"reference-count":19,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,6,27]],"date-time":"2026-06-27T00:00:00Z","timestamp":1782518400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>The present work explores the modelling and design of Interface Acoustic Wave (IAW)-based delay lines in SiO2\/ZnO (4 \u00b5m)\/SU-8\/SiO2 multilayer stacks and demonstrates that, by properly tailoring the acoustic wavelength and the SU-8 layer thickness, IAW delay lines can achieve performances comparable to, and in some cases superior to, those of conventional Surface Acoustic Wave (SAW) delay lines based on SiO2\/ZnO (4 \u00b5m) structures. In particular, the proposed devices exhibited untuned insertion losses down to 12 dB, propagation losses as low as 0.052 dB\/\u03bb, and electromechanical coupling coefficients K2 approaching 4%, exceeding those calculated for the corresponding SAW devices. The obtained results support the feasibility of compact, high-performance, and potentially packageless acoustic-wave devices for future telecommunications and sensing applications, especially in harsh or contamination-prone environments.<\/jats:p>","DOI":"10.3390\/mi17070781","type":"journal-article","created":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T05:58:04Z","timestamp":1782799084000},"page":"781","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Design of Low-Loss Acoustic Delay Lines Enabled by Dual-Mode Interface Acoustic Waves in SiO2\/ZnO\/IDT\/SU-8\/SiO2 Structures"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8363-2972","authenticated-orcid":false,"given":"Cinzia","family":"Caliendo","sequence":"first","affiliation":[{"name":"Institute for Photonics and Nanotechnology, National Research Council of Italy, IFN-CNR, Via del Fosso del Cavaliere 100, 00133 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Farouk","family":"Laidoudi","sequence":"additional","affiliation":[{"name":"Research Center in Industrial Technologies (CRTI), P.O. Box 64, Cheraga, Algiers 16014, Algeria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1261-9700","authenticated-orcid":false,"given":"Fabio Lo","family":"Castro","sequence":"additional","affiliation":[{"name":"Institute of Marine Engineering, National Research Council of Italy, CNR-INM\u2014Section of Acoustics and Sensors \u201cO.M. Corbino\u201d, Via del Fosso del Cavaliere 100, 00133 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Hashimoto, K. (2000). Surface Acoustic Wave Devices in Telecommunications, Springer.","DOI":"10.1007\/978-3-662-04223-6"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Ballantine, D., White, R.M., Martin, S.J., Ricco, A.J., Zellers, E., Frye, G., and Wohltjen, H. (1996). Acoustic Wave Sensors: Theory, Design and Physico-Chemical Applications, Elsevier.","DOI":"10.1016\/B978-012077460-9\/50001-0"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1109\/58.9325","article-title":"Propagation of boundary acoustic waves along a ZnO layer between two materials","volume":"35","author":"Irino","year":"1988","journal-title":"IEEE Trans. Ultrason. Ferroelectr. Freq. Control"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Caliendo, C., Benetti, M., Cannat\u00e0, D., Laidoudi, F., and Petrone, G. (2025). Interface Acoustic Waves in 128\u00b0 YX-LiNbO3\/SU-8\/Overcoat Structures. Micromachines, 16.","DOI":"10.3390\/mi16010099"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Caliendo, C., Benetti, M., Cannat\u00e0, D., and Laidoudi, F. (2025). Insight into the Propagation of Interface Acoustic Waves in Rotated YXLiNbO3\/ SU-8\/Si Structures. Micromachines, 16.","DOI":"10.3390\/mi16080861"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Caliendo, C., Benetti, M., Cannat\u00e0, D., and Laidoudi, F. (2026). Propagation of Upward and Downward Interface Acoustic Waves in Fused Silica\/ZnO\/SU-8\/Fused Silica-Based Structures. Sensors, 26.","DOI":"10.3390\/s26010139"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Caliendo, C., Benetti, M., Cannat\u00e0, D., Laidoudi, F., and Petrone, G. (2024). Experimental and Theoretical Analysis of Rayleigh and Leaky-Sezawa Waves Propagating in ZnO\/Fused Silica Substrates. Micromachines, 15.","DOI":"10.20944\/preprints202406.1804.v1"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Caliendo, C., Benetti, M., Cannat\u00e0, D., and Laidoudi, F. (2024). Acoustoelectric Effect due to an In-Depth Inhomogeneous Conductivity Change in ZnO\/Fused Silica Substrates. 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