A High-Resolution Resonant MEMS Strain Gauge


An investigation into the development of a high-resolution micro-strain gauge is discussed here. The design presented is a resonant sensor in the form of a double-ended tuning fork (DETF) that employs MEMS technology to achieve maximum sensitivity at a high bandwidth.

System issues such as anchor design and tuning fork matching are discussed, but the primary focus of this project is to maximize the sensitivity of the sensor. The behavior of the sensor was modeled using Timoshenko beam theory in order to determine the influence that certain design parameters have on sensitivity. The Mathematica software package was used to simplify and then to numerically solve the system of differential equations that governs the vibration of the tuning fork tines.

The product of this analysis was a set of plots that graphically demonstrate how the natural frequency of the tines is affected by axial strain. From these frequency versus strain graphs, the effect that the material properties, tine dimensions, mode number, and degree of strain have on the sensitivity were determined.

The most significant results of the investigation are that the sensitivity is inversely proportional to the width of the tines, and the decrease in sensitivity as strain increases is proportional to the length of the tines. In general, smaller is better. Additionally, higher modes of vibration were found to lead to an increase in sensitivity.

Publication date: 
December 31, 2000
Publication type: 
Master's Thesis
Wolfson, M. A. (2000). A High-resolution Resonant MEMS Strain Gauge: Research Project. United States: University of California, Berkeley.

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