Large Stroke Vertical PZT Microactuator With High-Speed Rotational Scanning

Area of Science:

• Micro-optics and MEMS (Micro-Electro-Mechanical Systems)
• Piezoelectric materials and devices
• Biomedical imaging technologies

Background:

• Confocal endomicroscopy requires precise scanning mechanisms for real-time cross-sectional imaging.
• Existing microactuators often face limitations in achieving both large displacements and high scanning speeds.
• Thin-film piezoelectric materials offer potential for miniaturized and efficient actuator designs.

Purpose of the Study:

• To present a novel thin-film piezoelectric microactuator integrating active vertical and passive rotational scanning.
• To demonstrate the capability of the microactuator for real-time cross-sectional imaging applications.
• To characterize the performance of the microactuator in terms of displacement, bandwidth, and scanning range.

Main Methods:

• Fabrication of a thin-film lead-zirconate-titanate (PZT) unimorph bending beam microactuator.
• Integration of active vertical translational scanning and passive resonant rotational scanning mechanisms.
• Characterization of actuator performance using voltage-controlled displacement and resonance frequency measurements.

Main Results:

• Achieved nearly 200-μm vertical displacement at 18 V with a bandwidth > 200 Hz.
• Obtained ±5.5° mechanical resonance at 3.8 kHz with ±2 V excitation.
• Demonstrated the combined large translational and high-speed rotational scanning capabilities.

Conclusions:

• The developed piezoelectric microactuator effectively combines large vertical motion with high-speed rotational scanning.
• This novel scanning approach is suitable for enabling real-time cross-sectional imaging in dual-axis confocal endomicroscopes.
• The microactuator represents a significant advancement in miniaturized scanning technologies for biomedical applications.