High aspect ratio microleverages based on silicon-on-insulator wafer

To amplify the moving distance of microactuators, high aspect ratio two-stage microleverages were designed and theoretically analyzed. The micro structures were simulated with finite element method (FEM) to predict the performance precisely and investigate the factors affecting the microleverages. It is shown that dimensions of flexible beams and the stiffness of output systems significantly influence the amplification factor of microleverages. This mechanism amplifies tiny displacement via elastic deformation of the flexible beams instead of rotation pins. The designed microleverages incorporated with electrothermal microactuators were fabricated on a silicon-on-insulator (SOI) wafer with deep reactive ion etching (DRIE) technology, and successfully released in 40% HF solution at room temperature. The microdevices were tested on a probe station, and the measured displacement and amplification factor are 36 μm and 18.9 respectively under applied voltage of 14 V and well coincide with the simulated results.