{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T14:11:39Z","timestamp":1789654299474,"version":"4.0.0"},"reference-count":20,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2013,2,27]],"date-time":"2013-02-27T00:00:00Z","timestamp":1361923200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Recently, an acoustic waveguide sensor based on multiple mode conversion of surface acoustic waves at the solid\u2014liquid interfaces has been introduced for the concentration measurement of binary and ternary mixtures, liquid level sensing, investigation of spatial inhomogenities or bubble detection. In this contribution the sound wave propagation within this acoustic waveguide sensor is visualized by Schlieren imaging for continuous and burst operation the first time. In the acoustic waveguide the antisymmetrical zero order Lamb wave mode is excited by a single phase transducer of 1 MHz on thin glass plates of 1 mm thickness. By contact to the investigated liquid Lamb waves propagating on the first plate emit pressure waves into the adjacent liquid, which excites Lamb waves on the second plate, what again causes pressure waves traveling inside the liquid back to the first plate and so on. The Schlieren images prove this multi reflection within the acoustic waveguide, which confirms former considerations and calculations based on the receiver signal. With this knowledge the sensor concepts with the acoustic waveguide sensor can be interpreted in a better manner.<\/jats:p>","DOI":"10.3390\/s130302777","type":"journal-article","created":{"date-parts":[[2013,2,27]],"date-time":"2013-02-27T11:43:57Z","timestamp":1361965437000},"page":"2777-2785","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Multi Reflection of Lamb Wave Emission in an Acoustic Waveguide Sensor"],"prefix":"10.3390","volume":"13","author":[{"given":"Martin","family":"Schmitt","sequence":"first","affiliation":[{"name":"Institute of Sensor and Actuator Technology, Coburg University of Applied Sciences,  Am Hofbrauhaus 1, 96450 Coburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sergei","family":"Olfert","sequence":"additional","affiliation":[{"name":"Measurement Engineering Group, Faculty of Electrical Engineering, Computer Science and Mathematics, University Paderborn, Warburger Str. 100, 33098 Paderborn, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jens","family":"Rautenberg","sequence":"additional","affiliation":[{"name":"Measurement Engineering Group, Faculty of Electrical Engineering, Computer Science and Mathematics, University Paderborn, Warburger Str. 100, 33098 Paderborn, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gerhard","family":"Lindner","sequence":"additional","affiliation":[{"name":"Institute of Sensor and Actuator Technology, Coburg University of Applied Sciences,  Am Hofbrauhaus 1, 96450 Coburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bernd","family":"Henning","sequence":"additional","affiliation":[{"name":"Measurement Engineering Group, Faculty of Electrical Engineering, Computer Science and Mathematics, University Paderborn, Warburger Str. 100, 33098 Paderborn, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5068-8929","authenticated-orcid":false,"given":"Leonhard","family":"Reindl","sequence":"additional","affiliation":[{"name":"Laboratory for Electrical Instrumentation, Department of Microsystems Engineering-IMTEK, University Freiburg, Georges-Kohler-Allee 106, 79110 Freiburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2013,2,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1002\/1616-8984(200105)9:1<105::AID-SEUP105>3.0.CO;2-I","article-title":"Microacoustic sensors for liquid monitoring","volume":"9","author":"Herrmann","year":"2001","journal-title":"Sens. Update"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Ballantine, D.S., White, R.M., Martin, S.J., Ricco, A.J., Zellers, E.T., Frye, G.C., and Wohltjen, H. (1997). Acoustic Wave Sensors Theory, Design, and Physico-Chemical Applications, Academic Press.","DOI":"10.1016\/B978-012077460-9\/50001-0"},{"key":"ref_3","unstructured":"Thompson, W., and Stone, D.C. (1997). Surface-Launched Acoustic Wave Sensors, John Wiley and Sons, Inc."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Lindner, G. (2008). Sensors and actuators based on surface acoustic waves propagating along solid-liquid interfaces. J. Phys. D Appl. Phys.","DOI":"10.1088\/0022-3727\/41\/12\/123002"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1103\/RevModPhys.83.647","article-title":"Microscale acoustofluidics: Microfluidics driven via acoustics and ultrasonics","volume":"83","author":"Friend","year":"2011","journal-title":"Rev. Mod. Phys."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1109\/TUFFC.2010.1388","article-title":"On-line surveillance of lubricants in bearings by means of surface acoustic waves","volume":"57","author":"Lindner","year":"2010","journal-title":"IEEE Trans. Ultrason. Ferroelectr. Freq. Contr."},{"key":"ref_7","unstructured":"Meisenbach, L., Diller, W., Zeng, X., Schmitt, M., Hamperl, C., and Lindner, G. (2011, January 25\u201326). Touch Sensitive Tiles with Surface Acoustic Waves for Sanitary Applications (in German). Berlin, Germany."},{"key":"ref_8","unstructured":"Schmitt, M., Stich, S., Fromm, S., Fischer, F., and Lindner, G. (May, January 1\u2013). Detection and Removal of Droplets on Non-Piezoelectric Substrates via Mode Conversion of Lamb Waves. Waikoloa, HI, USA."},{"key":"ref_9","unstructured":"Lindner, G., Faustmann, H., Krempel, S., M\u00fcnch, M., Rothballer, S., and Singer, F. (May, January 19\u2013). Wave Propagation in an Acoustic Wave Guide Sensor for Liquids Driven by Pulsed Excitation of Surface Acoustic Waves. Honolulu, HI, USA."},{"key":"ref_10","unstructured":"Lindner, G., Faustmann, H., Frankenberger, S., M\u00fcnch, M., Plaum, K., Rothballer, S., and Unterberger, M. (October, January 3\u2013). A Versatile Acoustic Waveguide Sensor for Liquids Based on Multiple Mode Conversion at Solid-Liquid Interfaces. Vancouver, BC, Canada."},{"key":"ref_11","unstructured":"Faustmann, H., M\u00fcnch, M., Markert, W., and Lindner, G. (2008, January 7\u201310). Acoustic Liquid Sensor Based on Lamb Waves on Structural Materials. Dresden, Germany."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"959","DOI":"10.1016\/j.phpro.2010.01.123","article-title":"Measurement of the properties of liquids based on the dispersion of lamb waves in an acoustic waveguide","volume":"3","author":"Faustmann","year":"2010","journal-title":"Phys. Procedia."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Rautenberg, J., Bause, F., and Henning, B. (2011, January 7\u20139). Guided Acoustic Waves for Liquid Property Measurement. N\u00fcrnberg, Germany.","DOI":"10.5162\/sensor11\/a6.1"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"714","DOI":"10.1166\/sl.2011.1599","article-title":"Acoustic on-line monitoring of chemical reactions in liquids with integrated temperatur compensation","volume":"9","author":"Friedrich","year":"2011","journal-title":"Sens. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1063\/1.3703155","article-title":"Measurement of the emission of Lamb waves by a PVDF membrane hydrophone","volume":"1433","author":"Schmitt","year":"2012","journal-title":"AIP Conf. Proc."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Settles, G.S. (2001). Schlieren and Shadowgraph Techniques, Springer.","DOI":"10.1007\/978-3-642-56640-0"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"935","DOI":"10.1016\/j.phpro.2010.01.120","article-title":"A new method of spatial filtering for Schlieren visualization of ultrasound wave fields","volume":"3","author":"Unverzagt","year":"2010","journal-title":"Phys. Procedia."},{"key":"ref_18","first-page":"18","article-title":"Lateral displacement of total reflected ultrasound waves","volume":"2","author":"Schoch","year":"1952","journal-title":"Acoustica"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1109\/T-SU.1977.30919","article-title":"Theory of nonspecular reflection effects for an ultrasonic beam incident on a solid plate in a liquid","volume":"24","author":"Pitts","year":"1977","journal-title":"IEEE Trans. Sonic. Ultrason"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Schmitt, M., Schmidt, K., Tietze, S., and Lindner, G. (2010, January 18\u201319). Detection of Droplets on Non-Piezoelectric Substrates via Mode Conversion of Lamb Waves. N\u00fcrnberg, Germany.","DOI":"10.1109\/ICSENS.2010.5689878"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/13\/3\/2777\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:45:10Z","timestamp":1760219110000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/13\/3\/2777"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,2,27]]},"references-count":20,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2013,3]]}},"alternative-id":["s130302777"],"URL":"https:\/\/doi.org\/10.3390\/s130302777","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2013,2,27]]}}}