Behavior of Electrothermal Actuator Analyzed by Polynomial Point Interpolation Collocation Method

Area of Science:

• Computational mechanics
• Microactuator analysis
• Electrothermal-thermomechanical coupling

Background:

• V-shaped microactuators are crucial components in microelectromechanical systems (MEMS).
• Accurate analysis of their coupled electrothermal and thermomechanical behavior is essential for performance optimization.
• Existing methods may face challenges in efficiently handling the complex physics involved.

Purpose of the Study:

• To present a novel implementation of the Polynomial Point Interpolation Collocation Method (PPCM) for analyzing V-shaped microactuators.
• To validate the PPCM's capability in predicting the coupled electrothermal and thermomechanical responses.
• To assess the accuracy of PPCM against Finite Element Method (FEM) and experimental data.

Main Methods:

• Discretization of heat transfer and structural mechanics governing equations using PPCM.
• Fully coupled solution of the discrete electrothermal system via an incremental load method.
• Solving the discrete mechanical equation incorporating natural boundary conditions to compute displacement.

Main Results:

• The MQ radial basis function demonstrates good convergence with parameters pa=1 and pq=1.8.
• PPCM shows less than 1 °C temperature difference compared to FEM under a 6 V voltage.
• PPCM exhibits approximately 10% error (20 °C discrepancy) with experimental temperature data.
• Displacement error between PPCM and FEM is as low as 2 μm under a 12 V applied voltage.

Conclusions:

• The Polynomial Point Interpolation Collocation Method (PPCM) is a validated and effective numerical technique.
• PPCM accurately predicts the coupled electrothermal and thermomechanical behavior of V-shaped microactuators.
• The method shows promising potential for analyzing the driving characteristics of microactuators with high accuracy.