Development of a low cost hybrid Si/PDMS multi-layered pneumatic microvalve

We report on the design and fabrication of a low cost active microvalve with a soft elastomer membrane driven by pneumatic actuation. The valve was made in two separate parts, a fluidic part in biocompatible and optically transparent material (PDMS) and a robust pneumatic interface in silicon, which were assembled together. The main issue of alignment and localized selective bonding of the PDMS parts to preserve the membrane mobility, hence the valving function, is described. In this work we also investigated two types of silicon moulds for PDMS casting, made by KOH anisotropic wet etching or DRIE.