Localized Topological States beyond Fano Resonances via Counter-Propagating Wave Mode Conversion in Piezoelectric Microelectromechanical Devices

TL;DR

This paper introduces a novel MEMS device that uses topological wave mode interference in piezoelectric materials to enhance localized sensing capabilities beyond traditional Fano resonance methods.

Contribution

The work demonstrates a new MEMS design utilizing counter-propagating topological wave modes in AlScN to improve localized sensing and stability in frequency sources.

Findings

Successful implementation of topological wave mode interference in MEMS

Enhanced localization sensitivity for micro-scale parameters

Potential applications in stable frequency sources

Abstract

A variety of scientific fields like proteomics and spintronics have created a new demand for on-chip devices capable of sensing parameters localized within a few tens of micrometers. Nano and microelectromechanical systems (NEMS/MEMS) are extensively employed for monitoring parameters that exert uniform forces over hundreds of micrometers or more, such as acceleration, pressure, and magnetic fields. However, they can show significantly degraded sensing performance when targeting more localized parameters, like the mass of a single cell. To address this challenge, we present a new MEMS device that leverages the destructive interference of two topological radiofrequency (RF) counter-propagating wave modes along a piezoelectric Aluminum Scandium Nitride (AlScN) Su-Schrieffer-Heeger (SSH) interface. The reported MEMS device opens up opportunities for further purposes, including achieving more stable frequency sources for communication and timing applications.