  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.
