Magnetoactive Acoustic Metamaterials
Abstract
Acoustic metamaterials with negative constitutive parameters (modulus and/or mass density) have shown great potential in diverse applications ranging from sonic cloaking, abnormal refraction and superlensing, to noise canceling. In conventional acoustic metamaterials, the negative constitutive parameters are engineered via tailored structures with fixed geometries; therefore, the relationships between constitutive parameters and acoustic frequencies are typically fixed to form a 2D phase space once the structures are fabricated. Here, by means of a model system of magnetoactive lattice structures, stimuli‐responsive acoustic metamaterials are demonstrated to be able to extend the 2D phase space to 3D through rapidly and repeatedly switching signs of constitutive parameters with remote magnetic fields. It is shown for the first time that effective modulus can be reversibly switched between positive and negative within controlled frequency regimes through lattice buckling modulated by theoretically predicted magnetic fields. The magnetically triggered negative‐modulus and cavity‐induced negative density are integrated to achieve flexible switching between single‐negative and double‐negative. This strategy opens promising avenues for remote, rapid, and reversible modulation of acoustic transportation, refraction, imaging, and focusing in subwavelength regimes.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 11, 2018
- Source ID
- 10.1002/adma.201706348
Entities
People
- Guoliang Huang
- Kunhao Yu
- Nicholas X. Fang
- Qiming Wang
Organizations
- Air Force Office of Scientific Research
- Massachusetts Institute of Technology
- National Science Foundation
- University of Missouri
- University of Southern California