Design, fabrication, and dynamics of an electromagnetic vertical microactuator for endomicroscopy

Advanced microscopy techniques can permit imaging beneath the tissue surface in hollow organs where cancer can begin. This work examines the design, modeling, fabrication and control process for an electromagnetic z-displacement, or into-tissue, scanning microactuator based on semiconductor fabrication methods. Dynamic modeling and control of the microactuator allows it to perform large vertical displacements despite nonlinearities of thick-film magnetic material behavior and closely-spaced dynamic modes from the compliant actuator structures. Nearly single frequency oscillation of >100 μm vertical displacement at 15 V is achieved by implementing an open-loop input linearization control signal. Nearly pure vertical motion of the microstage prevents the focal point of actuator lens from deviating from an axial laser path, necessary to capture images with high resolution.