Single-crystal silicon actuator arrays for micro manipulation tasks

Arrays of electrostatic MEMS actuators have been fabricated using a modified, multi-layer SCREAM (S_ingle-C_rystal R_eactive E_tching and M_etallization) process. The devices consist of released, torsionally suspended grids with high aspect ratio single-crystal silicon (SCS) tips. They can be used to generate a force field for the manipulation of small, flat objects. Calculations and experiments show that the actuator array is strong enough to move macroscopic parts. An individual actuator can generate a force of approximately 10 μN and a displacement of 5 μm. Monolithic arrays have been built reaching a size of up to 10 cm² , with up to 15000 individual single-crystal silicon actuators on one chip. We investigate micro actuators for manipulation tasks, and discuss important issues and trade-offs in design, processing and fabrication. We describe manipulation experiments in which small, flat objects where lifted and moved. We conclude with an outlook on applications of programmable actuator arrays to more elaborate micro manipulation tasks and give an outline on how they can be used for transporting, positioning, sorting, and assembly of small parts