Development of a 2D Mechanical Resonant Push-Pull Scanning Endoscope

Abstract

In recent years, miniature scanner technologies, including micro-electro-mechanical system (MEMS) scanners, have started to appear on the market. Most miniature scanner technologies utilize MEMS scanner mirrors. However, this approach has many limitations. In the meanwhile, a competing technology called fiber optic resonant scanner (FORS) has also been developed in order to obtain forward image. An off-the-shelf piezoelectric actuator at the base to create transverse vibrations of a resonating optical fiber has shown to be an effective method for generating 1D and 2D laser line scans. We previously developed a 2D micro image display device that utilized MEMS-based waveguide to replace the optical fiber, which can potentially overcome the size limitations of mirror-based display. In this research, an improved waveguide scanner system using a fully integrated MEMS-based push-pull actuator is presented. This prototype features monolithic integration of the waveguide, actuator, and light source, and removes the dependence on external actuators used by the previous design. The transmission efficiency is low and cantilever is slightly under tensile stress due to inherent imperfection in the process imperfection and tooling in fabrication. Nevertheless, 2D light scanning pattern is successfully demonstrated using 1D push-pull actuation.