Reconfigurable acoustic multiplexer/demultiplexer using time division

Abstract

Implementing guided-wave technologies in mechanical systems has always been a significant challenge due to losses associated with defects and sharp angles. Inspired by quantum Hall effects in condensed matter physics, mechanical topological insulators (TIs) have recently addressed these issues using efficient and robust signal transport supported by backscattering-immune topological protection. In this Letter, we demonstrate the first mechanical TI-based multiplexer/demultiplexer using acoustic waves. Triangular arrays of circular piezoelectric disks bonded to an aluminum host medium, shunted through external circuits with equivalent negative capacitance, break inversion symmetry and create topologically protected interface states. Combined with programmable switches, the device enables acoustic waves to travel efficiently from an input source to multiple output receivers, or vice versa, via dynamic topological interfaces. The proposed acoustic multiplexer/demultiplexer is envisioned to find application in wave-based devices, as an accompaniment to ubiquitous surface acoustic wave filtering used in communication devices, such as cell phones, radios, and computer peripherals.