Micro Motion Amplifiers for Compact Out-of-Plane Actuation

Area of Science:

• Microelectromechanical Systems (MEMS)
• Actuator Technology
• Tactile Interface Development

Background:

• Small-scale actuators are crucial for tactile interfaces but often lack sufficient force and displacement.
• Existing designs may require larger footprints to meet performance demands.

Purpose of the Study:

• To develop 2-mm² out-of-plane microactuators capable of high force and displacement.
• To investigate the use of MEMS-enabled half-scissor amplifiers for amplifying in-plane motion to out-of-plane motion.

Main Methods:

• Fabrication of microactuators using lithographically patterned SU-8 epoxy and polyimide.
• Integration of piezoelectric extensional actuators with micro-scissor mechanisms.
• Characterization of actuator performance by varying micro-scissor angle, flexure thickness, and adhesive type.

Main Results:

• Demonstrated out-of-plane microactuators producing up to 6.3 µm displacement and 16 mN blocking force at 170 V.
• Achieved a high displacement-blocking force product per unit area of up to 50 mN·µm/mm².
• Optimized micro-scissor design, particularly reducing the scissor angle, significantly improved actuator performance.

Conclusions:

• The developed MEMS microactuators offer a compact solution for generating substantial out-of-plane force and displacement.
• The half-scissor amplification mechanism is effective for enhancing actuator performance in small areas.
• The findings pave the way for advanced, high-performance tactile interfaces and other micro-scale applications.