A Robust Compact Lens Scanner with Large Tunable Range

This paper reports a compact lens scanner with large tunable range and high stiffness. A tunable range of over $100\ \mu \mathrm{m}$ has been achieved by using a unique serpentine inverted-series-connected (ISC) electrothermal bimorph actuator design, and a high stiffness of 10 N/m is obtained by integrating 36 ISC actuators equally distributed along the perimeter of the central ring-shaped platform. This stiffness is approximately 43 times of that previously reported in [1]. The clear aperture is 1.8 mm in diameter and the diameter of the entire scanner is only 4.4 mm. This MEMS lens scanner can be used as miniature depth scanning engines for confocal or multiphoton endomicroscopic imaging.