Experimental characterization of a one-dimensional nonreciprocal acoustic metamaterial with anti-parallel diodes

Abstract

Characterization of a newly developed class of passive nonreciprocal acoustic metamaterials is presented in an attempt to quantify their ability of controlling the flow and distribution of acoustic energy in acoustic cavities and systems. The proposed nonreciprocal acoustic metamaterial (NAMM) cell consists of a one-dimensional acoustic cavity provided with piezoelectric flexible boundaries connected to an array of anti-parallel diodes to introduce the nonlinear damping effect that tends to break the reciprocity of the energy flow through the NAMM cell. A comprehensive experimental characterization of prototypes of the NAMM cells is presented here in order to investigate the effect of various anti-parallel diode arrangements on the nonreciprocal behavior of the cell. Furthermore, the experimental characterization aims also at demonstrating the effectiveness of the proposed NAMM in tuning the directivity, flow, and distribution of acoustic energy propagating through the metamaterial.

Non-reciprocal piezoelectric metamaterials with tunable mode shapes

“…The approaches adopted to the break the reciprocity vary from simple passive approaches to the more imaginative active means. Distinct among the passive approaches are those including constitutive nonlinearity (Liang et al, 2009;Gu et al, 2016;Merkel et al, 2018;Petrover and Baz, 2020;Raval et al, 2020), momentum bias (Fleury et al, 2014;Liu et al, 2015;Liu et al, 2019;Wiederhold et al, 2019), and gyroscopic coupling (Attarzadeh et al, 2019). The performance characteristics of the passive NMM are enhanced by providing them with active control capabilities as proposed, for example, by Popa and Cummer (2014), Popa et al (2015), Trainiti and Ruzzene (2016), Nasser et al (2017), Baz 2018 and Baz 2019a), Yi et al (2019), Karkar et al (2019), Zhai et al (2019) and Goldsberry et al, 2019 andGoldsberry et al, 2020. Other interesting active control approaches to break the reciprocity include the use of virtual gyroscopic controllers (Baz, 2018;Raval et al, 2021;Baz, 2022; and by introducing a unique eigen-structure tuning controller (Baz, 2020a, Baz, 2020bZhou and Baz, 2021).…”