Device and method for pressure-driven plug transport and reaction

Abstract

The present invention provides microfabricated substrates and methods of conducting reactions within these substrates. The reactions occur in plugs transported in the flow of a carrier-fluid.

1 . A method of conducting a reaction within at least one plug within a substrate comprising the steps of:
 introducing a carrier-fluid into a first channel of the substrate;   introducing at least two different plug-fluids which are immiscible with the carrier-fluid into the first channel at one or more plug-forming regions; and   applying a force to the first channel to induce a fluid flow in the substrate to form at least one plug that comprise a mixture of the plug-fluids;   wherein the cross section of a plug is substantially the same size as the cross section of the first channel at the plug-forming region.   
     
     
         2 . The method of  claim 1 , further comprising the step of accelerating mixing of the plug-fluids within a plug by flowing the plugs through a channel geometry designed to implement a baker's transformation. 
     
     
         3 . The method of  claim 1 , further comprising the step of accelerating mixing of the plug-fluids within a plug by varying the composition of at least one of the plug fluids or the carrier fluid. 
     
     
         4 . The method of  claim 1 , further comprising the step of accelerating mixing of the plug-fluids within a plug by varying the viscosity of at least one of the plug-fluids or carrier fluid. 
     
     
         5 . The method of  claim 1 , further comprising the step of accelerating mixing of the plug-fluids within a plug by varying the patterns on the channel walls. 
     
     
         6 . The method of  claim 1 , further comprising the step of accelerating mixing of the plug-fluids within a plug by varying the hydrophilic properties of at least a portion of the first channel or of a branch channel. 
     
     
         7 . The method of  claim 1 , further comprising the step of accelerating mixing of the plug-fluids within a plug by varying the electric charge of at least a portion of the first channel or a branch channel. 
     
     
         8 . The method of  claim 1 , further comprising a step of merging at least one plug with a second plug downstream of the plug-forming region in the first channel. 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . A method of accelerating the mixing of at least two plug fluids in at least one plug in a microchannel comprising the steps of:
 introducing a carrier fluid into a microchannel with at least a straight section and a first bend, wherein the bend is defined by a radius of curvature from the centerline of the straight section of the microchannel;   forming at least one plug from at least two plug fluids in the carrier fluid upstream of the first bend, wherein the plug fluids do not completely mix at the time of the forming of the plug, and wherein each of the two plug fluids are different and immiscible with the carrier fluid;   flowing the carrier fluid with the plug through the first bend;   wherein the mixing of plug fluids within the plug is accelerated compared to a similarly formed plug flowing through a straight microchannel.   
     
     
         12 . The method of  claim 11 , wherein the microchannel comprises a second bend downstream of the first bend. 
     
     
         13 . The method of  claim 12 , wherein the first bend has a different radius of curvature than the second bend. 
     
     
         14 . The method of  claim 12 , wherein the first bend has a similar radius of curvature to that of the second bend. 
     
     
         15 . The method of  claim 11 , wherein the microchannel has a first cross-sectional dimension along a first section and a different cross-sectional dimension along a second section. 
     
     
         16 . The method of  claim 11 , wherein the plug fluids do not substantially mix at the time of forming of the plug. 
     
     
         17 . The method of  claim 11 , wherein the carrier fluid comprises a fluorinated compound. 
     
     
         18 . A method comprising the steps of:
 introducing a carrier fluid into a microchannel comprising at least a straight section and a first bend, wherein the bend is defined by a radius of curvature from the centerline of the straight section of the microchannel;   forming at least one plug in the carrier fluid in the microchannel by introducing a first plug fluid through a first inlet located upstream of the first bend and in fluid communication with the microchannel so that the plug forms in the carrier fluid at the junction of the first inlet and the microchannel;   introducing a second plug fluid through a second inlet located downstream of the first inlet, located upstream of the first bend, and in fluid communication with the microchannel so that the second plug fluid is added to the at least one plug to form a plug containing the first and second plug fluids;   allowing the plug containing the first and second plug fluids to travel through the first bend;   wherein the mixing of plug fluids within the plug containing the first and second plug fluids is accelerated compared to a similarly formed plug flowing through a straight microchannel;   wherein the first and second plug fluids are immiscible with the carrier fluid and are different from each other.   
     
     
         19 . (canceled) 
     
     
         20 . (canceled)