Development of a MEMS microvalve array for fluid flow control

A microelectromechanical system (MEMS) microvalve array for fluid flow cont rol is described. The device consists of a parallel array of surface-microm achined binary microvalves working cooperatively to achieve precision flow control on a macroscopic level, Flow rate across the microvalve array is pr oportional to the number of microvalves open, yielding a scalable high-prec ision fluidic control system. Device design and fabrication, using a one-level polycrystalline silicon su rface-micromachining process combined with a single anisotropic bulk etchin g process are detailed, Performance measurements on fabricated devices conf irm feasibility of the fluidic control concept and robustness of the electr omechanical design, Air-flow rates of 150 ml/min for a pressure differentia l of 10 kPa were demonstrated. Linear how control was achieved over a wide range of operating flow rates. A continuum fluidic model based on incompressible low Regnolds number flow theory was implemented using a finite-difference approximation. The model a ccurately predicted the effect of microvalve diaphragm compliance on flow r ate. Excellent agreement between theoretical predictions and experimental d ata was obtained over the entire range of flow conditions tested experiment ally. [351].