MEMS resonant load cells for micro-mechanical test frames: feasibility study and optimal design

Abstract

This paper presents the design, optimization and manufacturing of a novel micro-fabricated load cell based on a double-ended tuning fork. The device geometry and operating voltages are optimized for maximum force resolution and range, subject to a number of manufacturing and electromechanical constraints. All optimizations are enabled by analytical modeling (verified by selected finite elements analyses) coupled with an efficient C++ code based on the particle swarm optimization algorithm. This assessment indicates that force resolutions of ∼0.5-10 nN are feasible in vacuum (∼1-50 mTorr), with force ranges as large as 1 N. Importantly, the optimal design for vacuum operation is independent of the desired range, ensuring versatility. Experimental verifications on a sub-optimal device fabricated using silicon-on-glass technology demonstrate a resolution of ∼23 nN at a vacuum level of ∼50 mTorr. The device demonstrated in this article will be integrated in a hybrid micro-mechanical test frame for unprecedented combinations of force resolution and range, displacement resolution and range, optical (or SEM) access to the sample, versatility and cost.

Protocols for the Optimal Design of Multi‐Functional Cellular Structures: From Hypersonics to Micro‐Architected Materials

“…An economical and versatile device, capable of covering the entire range of force and displacement described above, has been recently introduced by one of the authors (Fig. ) . In the proposed design, the sensor is a micro‐fabricated Silicon double‐ended tuning fork (DETF), whose working principle is the change in natural frequency of vibration in a pair of parallel and connected beams upon application of an external axial force.…”

“…The displacement actuator is a commercially available nano‐stage, while the load cell (inset) is microfabricated. (b) Detail of the microfabricated load cell (From Torrents et al . and Azgin et al …”

Research on Novel CMUTs for Detecting Micro-Pressure with Ultra-High Sensitivity and Linearity

“…Consequently, resonant pressure sensors have emerged as promising candidates for higher-level sensing domains. Among all the sensors, the typical representative device is the silicon micro-resonant MEMS pressure sensor [12].…”

Nano-resonator dynamic behavior based on nonlocal elasticity theory

“…1 One important type of MEMS is resonator which has various applications. 2–6 Due to nonlinear behavior of this device caused by nonlinear electrical force, squeezing film damping, mid-plane stretching, and other geometrical nonlinearities, some complicated phenomena have been seen in the dynamic behavior of resonators. Many studies have been performed to investigate various nonlinear dynamic phenomena such as bending of the frequency–response curve and jump phenomenon in MEMS resonators.…”