Investigation on Lifting Angle of Polyimide Self-assembly Surface Micromachined Structure

This study presents a polyimide (PI) self-assembly technique for the development of three-dimensional surface micromachined structures. The effects of the geometric factors and the curing temperature of the PI elastic joints on the lifting angle of such microstructure are investigated. Under the optimized curing condition (380°C), a maximum 74° lifting angle of a 5.2 × 10−11 kg-weight polysilicon microplate can achieved utilizing the large surface-tension force of a single PI joint. The lifting angle of the thermally actuated 3-D microstructures can be demonstrated in nearly directional proportion to the length/width-thickness ratio of PI joint and the temperature difference temperature.