Electrostatic repulsive out-of-plane actuator using conductive substrate

Area of Science:

• Microelectromechanical Systems (MEMS)
• Actuator Technology
• Nanotechnology

Background:

• Existing two-layer and three-layer electrostatic repulsive out-of-plane actuators have limitations in fabrication requirements and fill factor.
• Optimizing actuator performance, specifically driving force and theoretical stroke, is crucial for advanced applications like deformable mirrors.

Purpose of the Study:

• To propose and theoretically model a pseudo-three-layer electrostatic repulsive out-of-plane actuator.
• To evaluate the performance of the proposed actuator against existing two-layer and three-layer designs.
• To experimentally validate the enhanced performance of the pseudo-three-layer configuration in a deformable mirror.

Main Methods:

• Development of a theoretical model for the pseudo-three-layer actuator.
• Numerical calculation using Schwarz-Christoffel mapping to solve the theoretical model.
• Experimental operation of a 19-element deformable mirror in both two-layer and pseudo-three-layer modes.

Main Results:

• Theoretical and simulated results indicate superior driving force and theoretical stroke for the pseudo-three-layer actuator compared to two-layer and three-layer designs.
• The pseudo-three-layer configuration is compatible with parallel-plate and existing repulsive actuator structures.
• Experimental results show a larger displacement (0-4.5 μm) in pseudo-three-layer mode compared to two-layer mode for a DC driving voltage of 0-100 V.

Conclusions:

• The pseudo-three-layer electrostatic repulsive out-of-plane actuator offers significant performance improvements.
• This design provides a practical enhancement for micro-actuator applications, particularly in deformable mirrors.
• The compatibility and enhanced displacement make it a promising alternative for advanced optical and MEMS systems.