Microfluidic pump

Abstract

A microfluidic pump is provided for managing fluid flow in disposable assay devices, which provides constant flows even at very low flow rates. Devices utilizing the microfluidic pump, as well as methods for manufacture and performing a microfluidic process are also provided.

1 . A pump, comprising:
 a channel defined by (a) a groove in a first surface of a first substrate, and (b) a second surface of a second substrate; and   an actuator configured to compress a portion of the second substrate into the groove of the first substrate without substantially deforming the groove.   
     
     
         2 . The pump of  claim 1 , wherein the actuator is configured to translate along an axis of the groove. 
     
     
         3 . The pump of  claim 1 , wherein the groove has a height and the height is at least about 10 microns, at least about 20 microns, at least about 30 microns, or at least about 50 microns. 
     
     
         4 . The pump of  claim 1 , wherein the groove has a height and the height is about 1000 microns or less, about 500 microns or less, about 250 microns or less, about 125 microns or less, about 100 microns or less, about 75 microns or less. 
     
     
         5 . The pump of  claim 1 , wherein the first and second substrates are substantially planar. 
     
     
         6 . The pump of  claim 1 , wherein the channel has an inlet and an outlet and a distance between the inlet and the outlet is at least about 1 mm, at least about 2.5 mm, at least about 5 mm, at least about 10 mm, at least about 25 mm. 
     
     
         7 . The pump of  claim 1 , wherein the channel has an inlet and an outlet and a distance between the inlet and the outlet is about 250 mm or less, 100 mm or less, about 75 mm or less, about 50 mm or less, about 25 mm or less. 
     
     
         8 . The pump of  claim 1 , wherein the pump is disposed in fluidic communication with a microfluidic device. 
     
     
         9 . The pump of  claim 8 , wherein the microfluidic device comprises at least one microchannel configured to receive a liquid sample suspected of containing at least one target and the microchannel comprises at least one reagent for use in determining the presence of the at least one target. 
     
     
         10 . The pump of  claim 9 , wherein the pump is configured to produce a gas pressure acting upon a distal gas-liquid interface of the liquid sample when the distal gas-liquid interface of the liquid sample is disposed within the microchannel of the microfluidic device. 
     
     
         11 . The pump of  claim 10 , wherein a proximal gas-liquid interface of the liquid sample is exposed to an ambient atmosphere. 
     
     
         12 . The pump of  claim 10 , wherein the gas pressure acting upon the distal gas-liquid interface of the liquid sample is less than an ambient gas pressure. 
     
     
         13 . The pump of  claim 8 , wherein the first and second substrates are disposed within the microfluidic device. 
     
     
         14 . The pump of  claim 9 , wherein the microchannel of the microfluidic device comprises the liquid sample disposed therein. 
     
     
         15 . The pump of  claim 14 , wherein the liquid sample comprises urine or at least one liquid component of blood. 
     
     
         16 . The pump of  claim 9 , wherein the actuator is configured to provide a rate of flow of the liquid sample within the microchannel of the microfluidic device of at least about 1 nl/s, at least about 5 nl/s, at least about 10 nl/s, at least about 25 nl/s, at least about 50 nl/s, at least about 100 nl/s, at least about 250 nl/s, at least about 500 nl/s at least about 1000 nl/s. 
     
     
         17 . The pump of  claim 9 , wherein the actuator is configured to provide a rate of flow of the liquid sample within the microchannel of the microfluidic device of about 10,000 nl/s or less, about 5,000 nl/s or less, about 2,500 nl/s or less, at least about 1000 nl/s or less. 
     
     
         18 . The pump of  claim 9 , wherein a total volume of liquid sample within the microchannel is about 100 microliters or less, about 50 microliters or less, about 25 microliters or less, about 20 microliters or less. 
     
     
         19 . The pump of  claim 1 , wherein the channel has an uncompressed area and, when compressed by the actuator, the compressed portion of the second substrate occludes at least about 50%, at least about 75%, at least about 90%, at least about 95%, at least about 97.5%, at least about 99%, or essentially all of the uncompressed area of the channel. 
     
     
         20 . The pump of  claim 1 , wherein in the uncompressed state, the groove has a width and the width is at least about 50 microns, at least about 100 microns, at least about 200 microns, at least about 500 microns. 
     
     
         21 . The pump of  claim 20 , wherein, in the compressed state, the width of the groove is at least about 75%, at least about 90%, at least about 95%, at least about 97.5%, at least about 99%, or essentially the same as in the uncompressed state. 
     
     
         22 . The pump of  claim 1 , wherein, in the compressed state, the groove has a width and the width is about 2000 microns or less, about 1500 microns or less, about 1000 microns or less, about 750 microns or less about 600 microns or less. 
     
     
         23 . The pump of  claim 22 , wherein, in the compressed state, the height of the groove is at least about 75%, at least about 90%, at least about 95%, at least about 97.5%, at least about 99%, or essentially the same as in the uncompressed state. 
     
     
         24 . The pump of  claim 1 , wherein, in the uncompressed state, the second substrate has a first thickness overlying the groove and a second thickness spaced apart laterally a first distance from the groove and wherein the second thickness is at least about 110%, at least about 125%, at least about 150%, at least about 175%, or at least about 200% greater than the first thickness. 
     
     
         25 . The pump of  claim 24 , wherein the first distance is at about 50% greater than a width of the groove, about 75% greater than a width of the groove, about 100% greater than a width of the groove, about 200% greater than a width of the groove. 
     
     
         26 - 167 . (canceled)