Dong Erqian, Song Zhongchang, Zhang Yu, Ghaffari Mosanenzadeh Shahrzad, He Qi, Zhao Xuanhe, Fang Nicholas X
Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China.
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China.
Sci Adv. 2020 Oct 30;6(44). doi: 10.1126/sciadv.abb3641. Print 2020 Oct.
To maximize energy transmission from a source through a media, the concept of impedance matching has been established in electrical, acoustic, and optical engineering. However, existing design of acoustic impedance matching, which extends exactly by a quarter wavelength, sets a fundamental limit of narrowband transmission. Here, we report a previously unknown class of bioinspired metagel impedance transformers to overcome this limit. The transformer embeds a two-dimensional metamaterial matrix of steel cylinders into hydrogel. Using experimental data of the biosonar from the Indo-Pacific humpback dolphin, we demonstrate through theoretical analysis that broadband transmission is achieved when the bioinspired acoustic impedance function is introduced. Furthermore, we experimentally show that the metagel device offers efficient implementation in broadband underwater ultrasound detection with the benefit of being soft and tunable. The bioinspired two-dimensional metagel breaks the length-wavelength dependence, which paves a previously unexplored way for designing next-generation broadband impedance matching devices in diverse wave engineering.
为了使能量从源通过介质实现最大化传输，阻抗匹配的概念已在电气、声学和光学工程中确立。然而，现有的声阻抗匹配设计精确地延伸四分之一波长，设定了窄带传输的基本限制。在此，我们报道了一类前所未知的受生物启发的超凝胶阻抗变压器以克服这一限制。该变压器将钢圆柱体的二维超材料矩阵嵌入水凝胶中。利用来自印太驼背豚生物声纳的实验数据，我们通过理论分析证明，引入受生物启发的声阻抗函数时可实现宽带传输。此外，我们通过实验表明，超凝胶装置在宽带水下超声检测中能有效实现，且具有柔软和可调谐的优点。受生物启发的二维超凝胶打破了长度 - 波长依赖性，为在各种波动工程中设计下一代宽带阻抗匹配装置开辟了一条前所未有的途径。
