Note: an asymmetric flexure mechanism for comb-drive actuators

Area of Science:

• Mechanical Engineering
• Microelectromechanical Systems (MEMS)

Background:

• Traditional electrostatic comb-drive actuators utilize double parallelogram (DP-DP) flexures.
• Existing designs face limitations in stroke length and susceptibility to instability.

Purpose of the Study:

• To introduce and evaluate a novel asymmetric flexure design, the double parallelogram-tilted-beam double parallelogram (DP-TDP) flexure.
• To enhance the stroke capability and stability of electrostatic comb-drive actuators.

Main Methods:

• Design and fabrication of micro-actuators incorporating the DP-TDP flexure.
• Comparative experimental testing against actuators with traditional DP-DP flexures.
• Analysis of kinematic configuration and stiffness ratios.

Main Results:

• The DP-TDP flexure achieved a stroke of 149 μm at 86 V, double the 75 μm (at 45 V) from the DP-DP flexure.
• The new design maintained the same device footprint as the conventional design.
• The DP-TDP flexure demonstrated an improved stiffness ratio, enhancing resistance to sideways instability.

Conclusions:

• The DP-TDP flexure is a superior design for electrostatic comb-drive actuators, offering significantly increased stroke.
• This asymmetric flexure design provides enhanced kinematic performance and stability, crucial for MEMS applications.
• The findings pave the way for more capable and robust micro-actuator systems.