Three robust temperature-drift compensation strategies for a MEMS gravimeter

TL;DR

This paper proposes three robust temperature-drift compensation strategies for MEMS gravimeters, enhancing their long-term stability by mitigating thermal effects through material properties and structural design.

Contribution

It introduces three novel mechanisms for temperature compensation in MEMS gravimeters, focusing on material properties and structural adjustments that are robust and self-contained.

Findings

The first mechanism cancels thermal expansion with Young's modulus variation.

The second uses thermal expansion to counteract spring force changes.

The third compensates proof mass displacement via thermal expansion.

Abstract

Gravimeters fabricated with MEMS suffer from temperature-dependent drifts in their long-term stability. We analyze the thermal contributions to the signal, and we propose three mechanisms to mitigate their effects. The first one uses materials that fulfill the condition $\alpha_E=-2 \alpha$, where the thermal expansion is canceled by the temperature variation of the Young's modulus. The second one uses the thermal expansion to introduce a compression that compensates the variation in the force of the spring. In the third one, the expansion compensates the displacement of the proof mass in the sensor, rather than the force. The three mechanisms are robust since they only depend on the temperature of the sensor itself.