Mobile phase gradient generation microfluidic device

A microfluidic device for separating the components of a fluid sample, the microfluidic device comprising:

• (a) a gradient-generation means for generating a gradient of a selected mobile-phase component in a mobile phase by the use of pressure driven flow comprising
• (i) a substrate having a microchannel formed in a surface thereof, wherein the microchannel has an upstream terminus and a downstream terminus,
• (ii) a cover plate arranged over the substrate surface, wherein the cover plate, in combination with the microchannel, forms a mobile-phase holding conduit having a length defined by the upstream terminus and the downstream terminus,
• (iii) a plurality of inlet ports arranged along the length of the mobile-phase holding conduit, and
• (iv) an outlet port located downstream from the inlet ports of the mobile-phase holding conduit;
• (b) a separation conduit for separating the components of a fluid sample according to a specific component property;
• and
• (c) a mechanical switching structure for introducing the mobile phase from the gradient-generation means into the separation conduit.

A microfluidic device for separating the components of a fluid sample, the microfluidic device comprising:

• a substrate having a microchannel formed in a surface thereof;
• a cover plate arranged over the substrate surface, such that the cover plate, in combination with the microchannel, defines a separation conduit for separating the components of the fluid sample according to a specific component property, wherein the separation conduit has an inlet port and an outlet port;
• and
• an integrated mobile-phase source comprising a microconduit having a length defined by an upstream terminus and a downstream terminus, the microconduit containing a mobile phase that exhibits a gradient of a selected mobile-phase component along the length of the microconduit, wherein the gradient is generated by the use of a mechanical switching structure to provide pressure driven flow,
• wherein the integrated mobile-phase source is arranged to allow the mobile phase to be transported through the inlet port into the separation conduit and out of the outlet port.

A microfluidic device for producing a flow of mobile phase:

• (a) mobile-phase source comprising
• (i) a mobile-phase holding microconduit having a length defined by an upstream terminus and a downstream terminus, and an outlet port located at the downstream terminus, and
• (ii) a mobile phase, contained in the mobile-phase holding microconduit, that exhibits differing concentrations of selected mobile-phase component along the length of the mobile-phase holding microconduit, wherein the differing concentrations are generated by the use of pressure driven flow;
• and
• (b) a mechanical switching structure for pressurizing the microconduit to force the mobile phase within the microconduit to flow toward the downstream terminus along the length of the microconduit and out the outlet port.

A microfluidic device for producing a flow of mobile phase, the microfluidic device comprising:

• (a) a means for producing different concentrations of a selected mobile-phase component in different locations within a mobile phase by the use of pressure driven flow, comprising
• (i) a mobile-phase-holding microconduit having a length defined by an upstream terminus and a downstream terminus,
• (ii) an outlet port located at the downstream terminus of the mobile-phase holding microconduit, and
• (iii) at least one inlet port in fluid communication with the mobile-phase holding microconduit upstream from the outlet port;
• (b) a plurality of mobile-phase sources each containing a mobile phase, wherein each mobile phase contains a different concentration of a selected mobile-phase component;
• (c) a means for introducing plugs of mobile phase from the mobile-phase sources through the at least one inlet port into the mobile-phase holding conduit such that the plugs are arranged in a predetermined order along the length of the mobile-phase holding conduit;
• and
• (d) a mechanical switching structure for pressurizing the microconduit to force the mobile phase within the microconduit to flow toward the downstream terminus along the length of the microconduit and out the single outlet port.