Research ArticleMATERIALS SCIENCE

Bioinspired metagel with broadband tunable impedance matching

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Science Advances  30 Oct 2020:
Vol. 6, no. 44, eabb3641
DOI: 10.1126/sciadv.abb3641
  • Fig. 1 A design of BMIT based on dolphin’s structure.

    (A) Three-dimensional acoustic impedance distribution of the dolphin’s head and a sectioned tissue sample (photo credit: Zhongchang Song). (B) Acoustic impedance profile of the channel and its fitting curve for obtaining the impedance function of BMIT as γ(x)=γ0+ε[εQγ0]x/L to couple water at x = 0 with PZT at x = −L. (C) Schematic illustration of the two-dimensional metagel structure and the corresponding diameter profile of steel cylinders. (D) Acoustic field comparison between the numerical simulations of BMIT and QIT at the frequency of f0 = 60 kHz. (E) Acoustic field comparison between BMIT and QIT at the frequency of f0 = 120 kHz. (F) Frequency response comparison between the numerical simulations and theoretical solutions of BMIT and QIT.

  • Fig. 2 BMIT capable of overcoming the narrowband limit for impedance matching.

    (A) Dependencies of the transmission powers of the mismatched system, QIT, and BMIT on L/λ, where L/λ corresponds to ω/4ωc, Q = 22.8 is used for the PZT transducer, and the approximate solutions of BMIT from the small reflection and small impedance perturbation theories are also given. (B) Dependencies of the transmission powers of QIT and BMIT on L/λ, where Q = 11.4 and 32.1 correspond to aluminum and steel, respectively.

  • Fig. 3 Experimental measurement of BMIT for broadband transmission.

    (A) Systematic diagram of the experimental setup and the procedure to assemble a hydrogel with a two-dimensional hexagonal array of steel cylinders. (B) Effects of cylinder diameter and compression ratio on acoustic impedance (photo credit: Erqian Dong). (C) Frequency response comparisons between the experimental measurements and numerical simulations of QIT and BMIT, where the top and bottom curves correspond to L = 2.5 and 1.5 cm, respectively.

  • Fig. 4 Broadband impedance matching application of BMIT in underwater ultrasound detection.

    (A) and (B) correspond to L = 2.5 and 1.5 cm, respectively, and “W” and “O” represent steel wall and iron object, respectively. QIT and BMIT are coupled with the echosounder to range the following cases: (I) without object, (II) with an immobile object, and (III) with a swaying object.

Supplementary Materials

  • Supplementary Materials

    Bioinspired metagel with broadband tunable impedance matching

    Erqian Dong, Zhongchang Song, Yu Zhang, Shahrzad Ghaffari Mosanenzadeh, Qi He, Xuanhe Zhao, Nicholas X. Fang

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