Linas Svilainis , Valdas Eidukynas , Luca De Marchi , Andrius Chaziachmetovas
{"title":"利用垂直压电元件阵列改进空气耦合超声转导","authors":"Linas Svilainis , Valdas Eidukynas , Luca De Marchi , Andrius Chaziachmetovas","doi":"10.1016/j.sna.2025.117178","DOIUrl":null,"url":null,"abstract":"<div><div>Novel transducer construction is proposed: array of PVDF film strips placed parallel to each other with air gaps between. Films are oriented in such way that strip extension (31 mode) is aligned with emission direction. Transduction is improved by providing better acoustic impedance match to air and increased displacement of emitting surface. Two distinct operation modes are presented: i) emission from the gaps ii) emission from membrane attached to the edges at array top with lower edges backed.</div><div>In gap emission mode, the transduction efficiency is increased because of two mechanisms. The pressure produced by the expansion of the individual films is concentrated into narrow gap. Also, emission of edges due to height extension. Height extension (31 mode) is much higher than thickness expansion (33 mode) if film height is larger than film thickness. Low, 500 Rayl, equivalent acoustic impedance of gap emission is achieved at film thickness 10 μm and gap with 50 μm.</div><div>In membrane emission mode, only extension (31 mode) is used, pressure emitted is increased due to large membrane displacement and better match to air. Equivalent acoustic impedance is 500 kRayl at PVDF film thickness 40 μm and 200 μm air gap. Displacement is maximized if PVDF film with large transverse piezoelectric coefficient d<sub>31</sub> is used.</div><div>Experimental measurements are presented. Transmission sensitivity peak for gap emission was 155 mPa/V, for membrane emission mode it was 320 mPa/V. Impressive, more than 270 % fractional bandwidth was confirmed experimentally.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"396 ","pages":"Article 117178"},"PeriodicalIF":4.9000,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Air-coupled ultrasound transduction improvement using vertical piezoelements’ array\",\"authors\":\"Linas Svilainis , Valdas Eidukynas , Luca De Marchi , Andrius Chaziachmetovas\",\"doi\":\"10.1016/j.sna.2025.117178\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Novel transducer construction is proposed: array of PVDF film strips placed parallel to each other with air gaps between. Films are oriented in such way that strip extension (31 mode) is aligned with emission direction. Transduction is improved by providing better acoustic impedance match to air and increased displacement of emitting surface. Two distinct operation modes are presented: i) emission from the gaps ii) emission from membrane attached to the edges at array top with lower edges backed.</div><div>In gap emission mode, the transduction efficiency is increased because of two mechanisms. The pressure produced by the expansion of the individual films is concentrated into narrow gap. Also, emission of edges due to height extension. Height extension (31 mode) is much higher than thickness expansion (33 mode) if film height is larger than film thickness. Low, 500 Rayl, equivalent acoustic impedance of gap emission is achieved at film thickness 10 μm and gap with 50 μm.</div><div>In membrane emission mode, only extension (31 mode) is used, pressure emitted is increased due to large membrane displacement and better match to air. Equivalent acoustic impedance is 500 kRayl at PVDF film thickness 40 μm and 200 μm air gap. Displacement is maximized if PVDF film with large transverse piezoelectric coefficient d<sub>31</sub> is used.</div><div>Experimental measurements are presented. Transmission sensitivity peak for gap emission was 155 mPa/V, for membrane emission mode it was 320 mPa/V. Impressive, more than 270 % fractional bandwidth was confirmed experimentally.</div></div>\",\"PeriodicalId\":21689,\"journal\":{\"name\":\"Sensors and Actuators A-physical\",\"volume\":\"396 \",\"pages\":\"Article 117178\"},\"PeriodicalIF\":4.9000,\"publicationDate\":\"2025-10-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Sensors and Actuators A-physical\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0924424725009847\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENGINEERING, ELECTRICAL & ELECTRONIC\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Sensors and Actuators A-physical","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0924424725009847","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
Air-coupled ultrasound transduction improvement using vertical piezoelements’ array
Novel transducer construction is proposed: array of PVDF film strips placed parallel to each other with air gaps between. Films are oriented in such way that strip extension (31 mode) is aligned with emission direction. Transduction is improved by providing better acoustic impedance match to air and increased displacement of emitting surface. Two distinct operation modes are presented: i) emission from the gaps ii) emission from membrane attached to the edges at array top with lower edges backed.
In gap emission mode, the transduction efficiency is increased because of two mechanisms. The pressure produced by the expansion of the individual films is concentrated into narrow gap. Also, emission of edges due to height extension. Height extension (31 mode) is much higher than thickness expansion (33 mode) if film height is larger than film thickness. Low, 500 Rayl, equivalent acoustic impedance of gap emission is achieved at film thickness 10 μm and gap with 50 μm.
In membrane emission mode, only extension (31 mode) is used, pressure emitted is increased due to large membrane displacement and better match to air. Equivalent acoustic impedance is 500 kRayl at PVDF film thickness 40 μm and 200 μm air gap. Displacement is maximized if PVDF film with large transverse piezoelectric coefficient d31 is used.
Experimental measurements are presented. Transmission sensitivity peak for gap emission was 155 mPa/V, for membrane emission mode it was 320 mPa/V. Impressive, more than 270 % fractional bandwidth was confirmed experimentally.
期刊介绍:
Sensors and Actuators A: Physical brings together multidisciplinary interests in one journal entirely devoted to disseminating information on all aspects of research and development of solid-state devices for transducing physical signals. Sensors and Actuators A: Physical regularly publishes original papers, letters to the Editors and from time to time invited review articles within the following device areas:
• Fundamentals and Physics, such as: classification of effects, physical effects, measurement theory, modelling of sensors, measurement standards, measurement errors, units and constants, time and frequency measurement. Modeling papers should bring new modeling techniques to the field and be supported by experimental results.
• Materials and their Processing, such as: piezoelectric materials, polymers, metal oxides, III-V and II-VI semiconductors, thick and thin films, optical glass fibres, amorphous, polycrystalline and monocrystalline silicon.
• Optoelectronic sensors, such as: photovoltaic diodes, photoconductors, photodiodes, phototransistors, positron-sensitive photodetectors, optoisolators, photodiode arrays, charge-coupled devices, light-emitting diodes, injection lasers and liquid-crystal displays.
• Mechanical sensors, such as: metallic, thin-film and semiconductor strain gauges, diffused silicon pressure sensors, silicon accelerometers, solid-state displacement transducers, piezo junction devices, piezoelectric field-effect transducers (PiFETs), tunnel-diode strain sensors, surface acoustic wave devices, silicon micromechanical switches, solid-state flow meters and electronic flow controllers.
Etc...