Time- and space-variant wave transmission in helicoidal phononic crystals

TL;DR

This paper introduces a tunable wave transmission mechanism in helicoidal phononic crystals, enabling dynamic control of wave mixing and dispersion, with potential applications resembling an acoustic transistor.

Contribution

It presents a novel, shape-inspired design for dynamically tunable wave control in 1D helicoidal phononic crystals, demonstrating wave mixing and controllable dispersion.

Findings

Numerical demonstration of wave mixing and dispersion control.

Dynamic tuning of contact stiffness via torsional movements.

Proposal of an acoustic device functioning like a transistor.

Abstract

We present a dynamically tunable mechanism of wave transmission in 1D helicoidal phononic crystals in a shape similar to DNA structures. These helicoidal architectures allow slanted nonlinear contact among cylin- drical constituents, and the relative torsional movements can dynamically tune the contact stiffness between neighboring cylinders. This results in cross-talking between in-plane torsional and out-of-plane longitudinal waves. We numerically demonstrate their versatile wave mixing and controllable dispersion behavior in both wavenumber and frequency domains. Based on this principle, a suggestion towards an acoustic configuration bearing parallels to a transistor is further proposed, in which longitudinal waves can be switched on/off through torsional waves.