Devices and methods for fluid mixing

A microdevice for mixing fluids, comprising:

• a substrate containing a first mixing feature that terminates at a first opening on a surface of the substrate and is in fluid communication with a substrate inlet and an optional substrate outlet;
• a cover plate containing a second mixing feature that terminates at a second opening on a surface of the cover plate and is in fluid communication with a cover plate inlet and a cover plate outlet;
• and
• a means for producing relative sliding motion between the substrate and cover plate surfaces,
• wherein the substrate and cover plate surfaces are maintained in fluid-tight contact with each other such that relative sliding motion between the first and second mixing features induces fluid mixing through the first and second feature openings when fluid is present in the mixing features, and at least one mixing feature has a volume less than or equal to about 100 μL.

A method for mixing fluids, comprising the steps of:

• (a) filling a first mixing feature in a substrate with a first fluid, wherein the first mixing feature terminates at a first opening on a substrate surface;
• (b) filling a second mixing feature in a cover plate with a second fluid, wherein the second feature terminates at a second opening on a cover plate surface;
• and
• (c) producing relative sliding motion between the substrate and cover plate surfaces while maintaining the surfaces in fluid-tight contact with each other to induce mixing of the first and second fluids through the first and second openings.