Electrostatic Comb-Drive Actuator with High In-Plane Translational Velocity

Area of Science:

• Opto-mechanical engineering
• Microelectromechanical systems (MEMS)

Background:

• Comb-drive actuators are crucial for micro-scale motion applications.
• Fabrication techniques like deep reactive ion etching (DRIE) on silicon-on-insulator (SOI) enable complex MEMS designs.

Purpose of the Study:

• To design and characterize high-velocity comb-drive actuators with in-plane motion.
• To evaluate the opto-mechanical performance of MEMS devices for optical applications.

Main Methods:

• Fabrication of MEMS actuators using DRIE on SOI substrates with 80 μm etching depth.
• Opto-mechanical characterization using an optical cavity response method to determine travel range.
• Analysis of actuator performance including resonance frequency and spring linearity.

Main Results:

• Two designs achieved peak velocities of 1.48 m/s and 1.18 m/s.
• Record product of travel range and frequency for in-plane MEMS motion under atmospheric pressure.
• Achieved travel ranges of 9.1 µm at 26.1 kHz and 2 µm at 93.5 kHz.

Conclusions:

• The developed MEMS actuators demonstrate high performance for in-plane motion.
• Design choices impact the trade-off between travel range, linearity, and resonance frequency.
• The study validates theoretical predictions with experimental results for MEMS actuator performance.