Cellular shape micromachined actuator ribbons.

Area of Science:

• Microelectromechanical Systems (MEMS)
• Electrostatic Actuation
• Nanotechnology

Background:

• Traditional MEMS electrostatic actuators have limitations in force and displacement.
• Scaling challenges hinder the performance of existing microactuator designs.

Purpose of the Study:

• To introduce a new class of MEMS electrostatic actuators with enhanced force and displacement capabilities.
• To demonstrate the potential of 2D arrays for additive force and displacement in microactuators.

Main Methods:

• Design and fabrication of micromachined electrostatic actuators with submicron high aspect ratio transduction gaps.
• Arrangement of microscale actuator cells into two-dimensional arrays (up to 7600 cells).
• Characterization of actuator performance, including displacement, force, bending moment, and energy density.

Main Results:

• Demonstrated out-of-plane displacement up to 678 µm at 46 V.
• Achieved axial force of approximately 0.08 N (~8 gram-force) with 800 kPa of electrostatic stress.
• Reported energy density up to 1.42 mJ/cm³ for actuators (50 µm thick, 1-4 mm dimensions).

Conclusions:

• The novel 2D array configuration significantly enhances the force and displacement output of MEMS electrostatic actuators.
• This technology offers unprecedented performance for microscale actuation, opening new application possibilities.