Position Feedback-Control of an Electrothermal Microactuator Using Resistivity Self-Sensing Technique

Area of Science:

• Materials Science
• Mechanical Engineering
• Control Systems

Background:

• Microactuators require precise control for closed-loop systems.
• Traditional systems often involve complex structures for actuation and sensing.
• Smart materials offer potential for integrated sensing and actuation.

Purpose of the Study:

• To develop a position feedback-control system for nickel electrothermal microactuators.
• To implement a resistivity self-sensing technique for concurrent actuation and sensing.
• To simplify microactuator structures through integrated self-sensing.

Main Methods:

• Utilized nickel electrothermal microactuators.
• Implemented a resistivity self-sensing technique based on Joule heating.
• Developed a closed-loop control system using resistance change as the control parameter.

Main Results:

• Successfully demonstrated the self-sensing feedback control system.
• Achieved a tip displacement error of less than 3 µm over a 60 µm span.
• Showcased robustness against ambient temperature changes, with rapid repositioning within 5 seconds.

Conclusions:

• The resistivity self-sensing technique enables simple, integrated actuation and sensing in microactuators.
• The developed feedback control system offers high precision and rapid response.
• This approach simplifies microactuator design and enhances performance in closed-loop applications.