Parametric Design of Fixed-Geometry Microvalves: The Tesser Valve

Abstract

A parametric description of two existing types of planar fixed-geometry micropump valves, the nozzle-diffuser and the Tesla-type, can be accomplished with surprisingly few parameters. The planform shape for the former requires only four parameters and the latter only five. Following this observation, a new valve type, the Tesser valve, was created having features of both the Tesla-type and nozzle-diffuser that required only two additional parameters, for a total of seven. Our overall goal is to utilize formal optimization techniques and computational fluid dynamics (CFD) with a experimental testing program to achieve valve efficiency that would be very difficult if not impossible to determine empirically. In this study we utilized two-dimensional computations that revealed a strong dependence of diodicity on Reynolds number in the range common for current micropump designs. The study also showed that the Tesser valve was superior at low Reynolds number 10 < Re < 100, and the Tesla-type valve superior at higher Reynolds number 100 < Re < 2000.