Patent ID: 11867320
Assignee: NATIONAL RESEARCH COUNCIL OF CANADA
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F  B | IPC B  F

Claim 0:
1. A polymeric microfluidic valve comprising:
a plastic substrate;
a resilient deformable elastomeric membrane extending across the substrate, the substrate and membrane defining a valve region separating at least two microfluidic channels in a microfluidic device;
a valve seat in the valve region on one of the membrane and the substrate, the valve seat having an adhesion-controlled surface where the membrane and the substrate contact when the valve is closed; and
a control fluid chamber separated and sealed from the microfluidic channels by the membrane,, where:
the adhesion-controlled surface is provided with a relief pattern of microstructures that provide a plurality of separated top meeting surfaces and recessed surfaces, the top meeting surfaces collectively having a cumulative surface area less than 90% of an area spanned by the adhesion-controlled surface, and having fluid-filled voids between the top meeting surfaces when the valve is closed, the relief pattern being an open pattern in that the fluid-filled voids are inter-connected across the valve seat between opposite ends of the valve seat in the microchannel;
the relief pattern is provided either on the valve seat or the membrane or substrate facing the valve seat; and
the fluid-filled voids reduce adhesion between the membrane and the substrate in the spanned area compared to 1-adhesion if no microstructures were present in the spanned area and compared to 2-adhesion if the membrane and the substrate were in conformal contact over all available surfaces including the top meeting surfaces and the recessed surfaces.