MEMS 3D Scan Mirror with SU-8 Membrane and Flexures for High NA Microscopy

Area of Science:

• Optics and Photonics
• Micro-system Engineering
• Biomedical Imaging

Background:

• Confocal microscopy is crucial for high-resolution biological imaging.
• Existing systems often lack miniaturization and integrated focus control.
• Handheld devices require compact and efficient scanning solutions.

Purpose of the Study:

• To develop a Micro-Electro-Mechanical Systems (MEMS) beam scanner for integration into handheld confocal microscopes.
• To achieve biaxial scanning with simultaneous focus control.
• To enable advanced skin imaging applications.

Main Methods:

• Design and fabrication of a dual-axis gimbal structure with a large-stroke deformable mirror using SU-8 polymer.
• Utilizing SU-8 for both the deformable membrane and torsional hinges.
• Characterization of the opto-mechanical performance.

Main Results:

• Demonstrated biaxial scanning with raster and Lissajous patterns (mechanical scan angles of +/- 1.5 and +/- 3 degrees, respectively).
• Achieved focus control with a maximum deflection of 9 um.
• Successfully integrated a 4 mm diameter mirror into the MEMS device.

Conclusions:

• The developed MEMS beam scanner offers biaxial scanning and focus control capabilities.
• This technology is suitable for integration into handheld confocal microscopes for skin imaging.
• The device advances miniaturized optical systems for biomedical applications.