Design, Fabrication, And Testing Of A C-shape Actuator

SUMMARY This paper describes the design, fabrication, and testing of a microactuator, whose bimorph beams curl up to form a C-shape and reach hundreds of microns from the substrate. The multi-layer C-shape beams were designed by FEM nonlinear analysis and fabricated on a silicon wafer by surface micromachining involving polyimide and metal thin films. The large curvature (i.e., small radius of curvature) is achieved by utilizing the large residual stress difference between thin films. The device is normally curled up, and it opens up by either electrostatic or thermal actuation. The device was operated successfully in liquid as well as in air to their full range between complete curl up and flat positions, demonstrating tip displacements of over two hundred microns.