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

Claim 16:
17. A normally closed 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 is on the valve seat, or a meeting surface of the valve seat; and
the fluid-filled voids reduce adhesion between the membrane and the substrate in the spanned area, said adhesion reduction sufficient to permit initial opening times that are at least twice as fast as with a valve having no relief pattern of microstructures.