Design and fabrication of novel discrete actuators for microrobotic tasks

This paper reports a compliant monolithic multistable actuator which is able to switch its moving part between several stable positions linearly in one dimensional direction. The number of stable positions can be increased by extending the range of displacement of the moving part. The transition in each step of displacement is made between two adjacent stable positions. Upward and downward steps are made by a specific sequence of moving, opening and closing two internal clamps which are actuated using three subsystems. The principle and the design of each subsystem followed by the microfabrication process and experimental characterization are reported here. The fabricated prototypes of discrete actuator have shown a proper operation. A successful displacement over 12 upward steps, corresponding to 120.67 ± 0.08 μm distance, has been achieved. The mean displacement step consists of 10.06 μm and closely matches the designed one (10 μm).