A micromachined ultrasonic transducer (MUT)-type acoustic metamaterial that achieved acoustic impedance matching between materials with different acoustic impedances was successfully fabricated. The fabricated device consisted of a thin membrane that vibrated when acoustic waves impinged on the surface of the device, along with tapered trench structures located beneath the membrane. The device fabrication process consisted of seven steps, using four silicon wafers. An acoustic evaluation of the system with the fabricated MUT-type acoustic metamaterial showed that the water-to-silicon transmission property was 30% higher than that of a system without the MUT-type acoustic metamaterial. This result confirms that MUT-type acoustic metamaterials are useful for matching the acoustic impedance between materials with different acoustic impedances. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

中文翻译：

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用于阻抗匹配的 MUT 型声学超材料的制备和评估

成功制备了一种微机械超声换能器（MUT）型声学超材料，实现了不同声阻抗材料之间的声阻抗匹配。所制造的装置由薄膜和位于薄膜下方的锥形沟槽结构组成，当声波撞击装置表面时薄膜会振动。该器件制造过程由七个步骤组成，使用四个硅晶圆。对使用所制造的MUT型声学超材料的系统进行的声学评估表明，水硅传输性能比没有使用MUT型声学超材料的系统高30%。这一结果证实了MUT型声学超材料可用于匹配不同声阻抗材料之间的声阻抗。© 2024 日本电气工程师协会和 Wiley periodicals LLC。