Reflectance and fluorescence imaging with a MEMS dual-axes confocal microscope

Abstract

This paper presents a dual-axes confocal microscope based on a two-dimensional (2-D) MicroElectroMechanical system (MEMS) scanner. Dual-axes confocal microscopy provides high resolution in both transverse and axial directions, and is also well-suited for miniaturization and integration into endoscopes for <i>in vivo</i> imaging. The gimbaled MEMS scanner is fabricated on a double silicon-on-insulator (SOI) wafer (a silicon wafer bonded on a SOI wafer) and is actuated by self-aligned, vertical, electrostatic combdrives. The reflecting surface of the scanner is covered with a 10-nm aluminum layer. Reflectance and fluorescence imaging is successfully demonstrated in a breadboard setup. Images with a maximum field of view (FOV) of 340 μm x 420 μm are achieved at 8 frames per second. The transverse resolution is 3.9 μm and 6.7 μm for the horizontal and vertical dimensions, respectively.