A piezoelectric ultrasonic linear micromotor using a slotted stator

Area of Science:

• Robotics and Mechatronics
• Biomedical Engineering
• Materials Science

Background:

• Microrobotics and biomedical devices require precise, high-performance actuators.
• Existing ultrasonic motors face challenges in efficiency and miniaturization.
• Novel stator designs are crucial for advancing micro-scale motion control.

Purpose of the Study:

• To propose and design a novel ultrasonic micro linear motor utilizing longitudinal and bending modes.
• To investigate the role of a unique stator slot structure in optimizing motor performance.
• To enhance the suitability of ultrasonic motors for microrobotic and biomedical end-effect applications.

Main Methods:

• Design of a bar-type stator with a length-wise rectangular slot.
• Utilizing finite element analysis (FEA) to determine optimal slot dimensions.
• Experimental fabrication and testing of a prototype ultrasonic micro linear motor.

Main Results:

• The optimized slot design effectively tuned resonance frequencies and reduced unwanted displacement.
• The prototype motor (1.6 g) achieved a maximum velocity of 1.12 m/s and a maximum force of 3.4 N.
• A peak mechanical output power of 1.1 W was recorded, with a power-to-weight ratio of 688 W/kg.

Conclusions:

• The novel ultrasonic micro linear motor design demonstrates significant performance improvements.
• The slot structure is critical for enhancing vibration mode control and reducing coupling displacement.
• This motor shows great potential for advanced microrobotic and biomedical end-effect devices.