Axial beam scanning in multiphoton microscopy with MEMS-based actuator.

Area of Science:

• Biomedical Engineering
• Optical Microscopy
• Materials Science

Background:

• Multiphoton microscopy is a powerful technique for deep tissue imaging.
• Current limitations include restricted axial scanning capabilities and bulky instrumentation.
• Microelectromechanical systems (MEMS) offer miniaturization and precise motion control.

Purpose of the Study:

• To develop and demonstrate a remotely located MEMS actuator for axial beam scanning in multiphoton microscopy.
• To integrate this actuator with a 2D MEMS mirror for comprehensive 3D scanning.
• To evaluate the performance of the system for endomicroscopy applications.

Main Methods:

• Fabrication and integration of a MEMS actuator capable of >400 μm translation.
• Utilized a 2D MEMS mirror for lateral scanning (horizontal and vertical planes).
• Collected multiphoton excited fluorescence images at 5 frames per second.

Main Results:

• Achieved axial beam scanning over >400 μm range.
• Acquired images with fields-of-view up to 270 × 270 μm².
• Observed axial resolution between 4.5 and 7 μm.
• Demonstrated endomicroscopic imaging with >200 μm depth in the vertical plane.

Conclusions:

• The developed MEMS actuator provides effective axial scanning for multiphoton microscopy.
• The compact system is suitable for endomicroscopy, enabling deep tissue visualization.
• This technology enhances the capabilities of miniaturized optical imaging systems.