Bilayer microvalve arrays for pneumatic and fluidic applications

Abstract

A strained bilayer film with reinforcing members is used to open and close gas flow outlets in a microvalve array. The bottom layer of the bilayer film is compressive and the top layer is tensile. Reinforcing members are made from compressive material that accomplishes the dual objectives of reducing potential defects at the interface between the anchor region and the free region of the actuator, and controlling the stresses along the edges of the strained bilayer to avoid curling as the actuator unrolls from its normal coiled configuration in response to an applied voltage. Because of the configuration, the strained bilayer film occupies a minimal amount of space compared to other systems when the valve is opened, and it permits a higher density of microvalves to be utilized. Optional supports are provided over gas flow channel openings to increase the area over which the voltage is applied, increasing electrostatic stability of the actuators in maintaining their unrolled state for a variety of uses. Such uses include, but are not limited to, pneumatic manifolds or other practical uses that involve transmission of air or fluids, including for lab-on-a-chip applications, as well as for providing air flow channels for a configurable tactile tablet to provide the visually impaired with a tactile representation of shapes and designs, to name some examples.