A static fluid and a second fluid are placed into contact along a microfluidic free interface and allowed to mix by diffusion without convective flow across the interface. In accordance with one embodiment of the present invention, the fluids are static and initially positioned on either side of a closed valve structure in a microfluidic channel having a width that is tightly constrained in at least one dimension. The valve is then opened, and no-slip layers at the sides of the microfluidic channel suppress convective mixing between the two fluids along the resulting interface. Applications for microfluidic free interfaces in accordance with embodiments of the present invention include, but are not limited to, protein crystallization studies, protein solubility studies, determination of properties of fluidics systems, and a variety of biological assays such as diffusive immunoassays, substrate turnover assays, and competitive binding assays.

A medical fluid pneumatic manifold system includes a plurality of pump and valve chambers for controlling a flow of medical fluid, a header including a plurality of pneumatic passageways, each passageway in pneumatic communication with one of the pump or valve chambers, a plurality of electrically actuated pneumatic valves, and a plate defining a plurality of pneumatic apertures, wherein the header and the plurality of electrically actuated pneumatic valves are separately attached to the plate, such that each pneumatic aperture in the plate is placed in pneumatic communication with one of the plurality of pneumatic passageways of the header and one of the electrically actuated pneumatic valves.

A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.

The microfluidic devices and systems disclosed herein reduce sample loss and help decrease sample processing bottlenecks for applications such as next generation sequencing (NGS). The microfluidic devices include a plurality of reaction modules. Each reaction module may comprise one or more reaction circuits. Each reaction circuit may comprise a single reaction flow channel with each reaction circuit connected by a bridge flow channel. Alternatively, each reaction circuit may comprise two or more reaction flow channels connected by two or more bridge flow channels. The combination of any two bridge flow channels and a portion of the two or more reaction flow channels between the any two bridge flow channels defining may define the reaction circuit. The reaction module may be arranged as nodes connected by bridge flow channels or each reaction module may be arranged in a parallel fashion on the microfluidic device.