# High-velocity laser Doppler vibrometry measurements on an aluminum nitride bimorph wedge resonator

## TL;DR

Researchers developed a MEMS resonator that achieves 50 m/s velocity, a ten-fold improvement, enabling more sensitive inertial sensors for navigation.

## Contribution

Demonstration of a MEMS resonator reaching 50 m/s with nonlinear dynamics and material constraints explored.

## Key findings

- AlN bimorph wedge resonator achieved 50 m/s velocity, ten times higher than conventional MEMS.
- Duffing-type nonlinearities observed at large drive amplitudes in time- and frequency-domain measurements.
- Results show feasibility of operating MEMS at higher velocities for improved inertial sensing.

## Abstract

Recent advances in microelectromechanical systems (MEMS) have advanced inertial sensor technology. For resonant gyroscopes, sensitivity scales with the maximum velocity of the resonating mass, as higher velocities amplify the Coriolis force for faster and more accurate inertial signal detection—critical in navigation applications. Conventional MEMS remain in linear regimes, with velocities typically below 5 m/s. A recent Defense Advanced Research Projects Agency (DARPA) initiative challenges researchers to push resonator speeds toward material fracture limits, targeting up to 200 m/s and exploring regimes dominated by strong nonlinearities. This work investigates velocity limits in piezoelectrically driven mechanical resonators imposed by nonlinear dynamics and material constraints. We experimentally demonstrate an AlN bimorph wedge resonator reaching 50 m/s, achieving a ten-fold improvement over current limits. These results highlight the feasibility of operating MEMS devices at much higher velocities, paving the way for next-generation inertial sensors with increased performance. The resonator operates at a higher-order mode near 1.81 MHz, with clear evidence of Duffing-type nonlinearities at large drive amplitudes, as confirmed in time-domain and frequency-domain measurements.

Zihuan Liu and colleagues reported measurements on a MEMS resonator that reaches a mechanical velocity of 50 m/s, a ten-fold improvement over typical devices. These results show that operating MEMS near limits could enable much more sensitive inertial sensors for navigation.