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

We demonstrate a MEMS beam scanner capable of biaxial scanning with simultaneous focus control, for integration into a handheld confocal microscope for skin imaging. The device is based on a dual axis gimbal structure with an integrated largestroke deformable mirror. SU-8 polymer is used to construct both the deformable membrane as well as the torsional hinges for biaxial scanning. The 4 mm diameter mirror can perform raster pattern scanning with a range of +/- 1.5 degrees and Lissajous scanning with a range of +/- 3 degrees (mechanical scan angle), and has a maximum deflection of 9 um for focus control. The design, fabrication and characterization of the opto-mechanical performance of the MEMS device are presented in this paper.