Ultra-Low Resonance Frequency MEMS Gravimeter With Off-Resonance Closed-Loop Control

This paper reports on a MEMS gravimeter that has a closed-loop system to maintain an ultra-low resonance frequency of 1Hz. The low resonance frequency is attained by using a spring that is the resultant of positive mechanical stiffnesses and negative electrical stiffnesses. Voltage-tunability of the electrical stiffness enables ultra-small and tunable total stiffness. To attain a quick response... » read more

A Sub-1 Hz Resonance Frequency Resonator Enabled By Multi-Step Tuning For Micro-Seismometer

We propose a sub-1 Hz resonance frequency MEMS resonator that can be used for seismometers. The low resonance frequency is achieved by an electrically tunable spring with an ultra-small spring constant. Generally, it is difficult to electrically fine-tune the resonance frequency at a near-zero spring constant because the frequency shift per voltage will diverge at the limit of zero spring const... » read more