A planar unimorph-based actuator with large vertical displacement capability. I. Experiment.

Area of Science:

• Materials Science
• Mechanical Engineering
• Electrical Engineering

Background:

• Piezoelectric actuators are crucial for precise motion control.
• Existing designs often face limitations in displacement or force output.
• Developing actuators with improved performance is an ongoing research area.

Purpose of the Study:

• To describe a novel piezoelectric actuator design using a planar arrangement of series-connected unimorph elements.
• To present and validate an electromechanical model for predicting actuator performance.
• To investigate methods for enhancing the force output of the actuator.

Main Methods:

• Fabrication of two prototype actuators: one stick-built and one monolithic.
• Mechanical and electrical characterization of the actuators, including displacement versus voltage and displacement versus force measurements.
• Development and application of an electromechanical model for performance prediction.

Main Results:

• The measured performance of the prototype actuators closely matched the predictions of the developed electromechanical model.
• Both stick-built and monolithic actuators successfully produced displacements perpendicular to their plane.
• The addition of stiffeners was shown to significantly increase force output without compromising displacement-voltage characteristics.

Conclusions:

• The described piezoelectric actuator design effectively achieves additive vertical displacements through series-connected unimorph elements.
• The validated electromechanical model provides a reliable tool for predicting and optimizing actuator performance.
• The study confirms that structural modifications, such as adding stiffeners, can enhance force output, offering a pathway for tailored actuator applications.