A C-shaped hinge for displacement magnification in MEMS rotational structures

Area of Science:

• Micro-Electro-Mechanical Systems (MEMS)
• Mechanical Engineering
• Materials Science

Background:

• MEMS rotational structures are crucial components in various sensors and devices.
• Enhancing displacement and sensitivity in MEMS rotational structures is an ongoing research objective.
• Traditional designs like the lancet structure have limitations in achieved movement.

Purpose of the Study:

• To design, analyze, fabricate, and characterize two distinct MEMS rotational structures.
• To introduce and evaluate a novel symmetrical C-shaped structure with a tilted arm.
• To compare the performance of the novel C-shaped structure against a classical lancet structure.

Main Methods:

• Utilized thermal actuators for actuation in both MEMS structures.
• Employed Design of Experiments (DOE) for geometrical parameter optimization.
• Performed analytical modeling (Castigliano's second theorem) and Finite Element Method (FEM) simulations.
• Fabricated structures using Silicon-On-Insulator (SOI) wafers, bulk micromachining, and Deep Reactive Ion Etching (DRIE).
• Conducted experimental characterization to validate simulation and analytical results.

Main Results:

• The novel C-shaped MEMS rotational structure demonstrated a 28% improvement in delivered displacement compared to the lancet structure.
• Analytical modeling and FEM simulations showed good agreement with each other for the C-shaped structure's behavior.
• Experimental results closely matched the predictions from numerical analysis, confirming device performance.

Conclusions:

• The proposed C-shaped MEMS rotational structure effectively enhances displacement through its curved beam mechanism.
• The optimized C-shaped structure offers superior performance compared to the traditional lancet design.
• These MEMS rotational structures hold significant potential for applications requiring maximized displacement and enhanced sensitivity, such as accelerometers, gyroscopes, and resonators.