MEMS Based Dual-axes Confocal Reflectance Handheld Microscope for in vivo Imaging

We demonstrate a dual-axes confocal reflectance microscope in a 10-mm diameter handheld package. Miniaturization is achieved by using a barbell-shaped, gimbaled, two-dimensional MEMS scanner that is actuated by self-aligned vertical comb actuators. The maximum DC optical scan angles are plusmn3.3deg on the inner axis and plusmn1.0deg on the outer axis, and the corresponding resonance frequencies are 3.54 kHz and 1.1 kHz. The imaging rate is 30 frames/second, and the microscope achieves full-width-half-maximum (FWHM) transverse and axial resolutions of 8 mum and 10 mum, respectively