A passive check valve using microspheres for low pressure and low flow rate applications

A check valve using microspheres to resist fluid flow for low pressure and low flow applications is presented. The microvalve is fabricated using polydimethylsiloxane (PDMS) and uses polystyrene (PS) microspheres as fluid flow resistance elements. Experiments were performed with applied pressures of 0.2 kPa - 3 kPa. With Re<;1 the microvalve exhibited a minimum diodicity of 9.9 and a maximum diodicity of 26.7. This represents a significant increase in diodicity for microvalves in low Reynold´s number flow. The presented microvalve shows strong potential to rectify flow in reciprocating micropumps.