Active acoustic switches using 2D granular crystals

Abstract

We employ numerical simulations to study active transistor-like switches made from two-dimensional (2D) granular crystals containing two types of grains with the same size, but different masses. We tune the mass contrast and arrangement of the grains to maximize the width of the frequency band gap in the device. The input signal is applied to a single grain on one side of the device, and the output signal is measured from another grain on the other side of the device. Changing the size of one or many grains tunes the pressure, which controls the vibrational response of the device. Switching between the on and off states is achieved using two mechanisms: 1) pressure-induced switching where the interparticle contact network is the same in the on and off states, and 2) switching through contact breaking. In general, the performance of the acoustic switch, as captured by the gain ratio and switching time between the on and off states, is better for pressure-induced switching. We show that in these acoustic switches the gain ratio between the on and off states can be larger than $10^4$ and the switching time (multiplied by the driving frequency) is comparable to that obtained recently for sonic crystals and less than that for photonic transistor-like switches. Since the self-assembly of grains with different masses into 2D granular crystals is challenging, we describe simulations of circular grains with small circular knobs placed symmetrically around the perimeter mixed with circular grains without knobs. Using umbrella sampling techniques, we show that devices with grains with $3$ knobs most efficiently form the hexagonal crystals that yield the largest band gap.

16 pages, 23 figures

References in corpus (7)

• Continuum limit of amorphous elastic bodies: A finite-size study of low frequency harmonic vibrations
• Crystallization of a quasi-two-dimensional granular fluid
• Hysteresis and competition between disorder and crystallization in sheared and vibrated granular flow
• Slow relaxation in granular compaction
• Tunable Vibrational Band Gaps in One-Dimensional Diatomic Granular Crystals with Three-Particle Unit Cells
• Nucleation in sheared granular matter
• The response of jammed packings to thermal fluctuations

Cited by in corpus (7)

• Turing complete mechanical processor via automated nonlinear system design
• Evolving Programmable Computational Metamaterials
• Self-assembly and non-equilibrium phase coexistence in a binary granular mixture
• Universal Mechanical Polycomputation in Granular Matter
• Evolution of Adaptive Force Chains in Reconfigurable Granular Metamaterials
• Tuning the Size and Stiffness of Inflatable Particles
• Acoustic resonances in a confined set of macroscopic disks