High-Energy Density Micro-Machined Cellular Arrays of Electrostatic Actuators

This work presents micro-machined electrostatic actuator arrays capable of producing relatively large forces and wide displacement ranges. The actuators are comprised of a flexible silicon skeleton (mesh) with a network of trench refilling polysilicon electrodes electrically insulated and separated from the silicon walls by submicron air-gaps. The array architecture provides flexibility and large displacement by adding displacements from individual cells, while submicron gaps lead to relatively large actuation forces. Out of plane displacement of up to 230μm with actuation force of 0.3mN at the actuator tip has been measured for a 450 cell (1.05mm × 0.475mm) fabricated array with 90V actuation voltage.