Microfluidic Device

Abstract

The invention relates to a microfluidic device including a chamber having a fluid inlet, a fluid outlet and a sealable port. In some embodiments, the fluid inlet and the fluid outlet may be positioned to direct fluid flowing from the fluid inlet to the fluid outlet through the chamber. Various embodiments may include a sealable port which may be aligned with the chamber to allow material to be placed directly into, or removed from, the chamber from the exterior of the device when the sealable port is open, and to inhibit and/or prevent fluid escaping through the sealable port when the port is sealed.

1 . A microfluidic device comprising a chamber having a fluid inlet, a fluid outlet and a sealable port, wherein the fluid inlet and the fluid outlet are positioned to direct fluid flowing from the fluid inlet to the fluid outlet through the chamber, and wherein the sealable port is aligned with the chamber to allow material to be placed directly into, or removed from, the chamber from the exterior of the device when the sealable port is open, and to prevent fluid escaping through the sealable port when the port is sealed. 
     
     
         2 . The device of  claim 1 , further comprising an interconnect system which comprises:
 a first component having a conduit to carry fluid to the fluid inlet or away from the fluid outlet, wherein the first component is formed of a deformable material, and   a second component having a projecting portion, wherein a conduit passes through the projecting portion and the second component;   wherein the conduit of the first component is aligned with the conduit of the second component, wherein the projecting portion of the second component deforms an area of the first component surrounding the conduit therein so as to create a seal around the contiguous conduits of the first and second components, thus preventing any fluid from escaping as it flows from one conduit to the other conduit, and wherein the second component is for connecting the conduit therein to an external fluid source or sink.   
     
     
         3 . The device of  claim 2 , comprising an interconnect system for each of the fluid inlet and fluid outlet. 
     
     
         4 . The device of  claim 2 , wherein the interconnect system or systems each further comprises a guide positioned on the first component around the conduit therein and which mates with the projecting portion of the second component to align the conduit of the first component with the conduit of the second component. 
     
     
         5 . The device of  claim 1 , wherein the base of the chamber is formed from a substrate for supporting biological material. 
     
     
         6 . The device of  claim 5 , wherein the substrate is a standard glass or polystyrene microscopy slide or culture plate and the chamber is formed on at least a portion of the substrate. 
     
     
         7 . The device of  claim 5 , wherein the substrate is detachable from the device. 
     
     
         8 . The device of  claim 1  wherein the device is used for culturing cells. 
     
     
         9 . The device of  claim 1 , further comprising a housing. 
     
     
         10 . The device of  claim 1 , wherein the fluid inlet and the fluid outlet are positioned on opposite sides of the chamber. 
     
     
         11 . The device of  claim 1 , wherein the fluid inlet and the fluid outlet are positioned so that a material containment portion of the chamber is substantially unaffected by the flow of fluid through the chamber. 
     
     
         12 . The device of  claim 1 , wherein the fluid inlet and/or the fluid outlet each form at least about 20% of the area of one side of the chamber. 
     
     
         13 . The device of  claim 1 , wherein the fluid inlet and the fluid outlet are aligned with the top of the chamber. 
     
     
         14 . The device of  claim 1 , wherein the fluid inlet and fluid outlet comprise one or more flow restrictors. 
     
     
         15 . The device of  claim 1 , further comprising a conduit to carry fluid to the fluid inlet and a conduit to carry fluid away from the fluid outlet, wherein each conduit contains one or more flow dividers. 
     
     
         16 . The device of  claim 1 , wherein the sealable port forms a lid of the chamber. 
     
     
         17 . The device of  claim 1 , wherein the fluid is a liquid and the sealable port comprises a gas permeable membrane to allow gas such as oxygen to pass into the chamber. 
     
     
         18 . The device of  claim 1 , wherein the device further comprises a heater. 
     
     
         19 . The device of  claim 1 , wherein the device further comprises a sensor. 
     
     
         20 . The use of the device of  claim 1  for culturing cells or performing cell-based assays. 
     
     
         21 . An interconnect system for sealably connecting two fluid carrying conduits, the system comprising:
 a first component having a conduit and being formed of a deformable material; and   a second component having a projecting portion, wherein a conduit passes through the projecting portion and the first component;   wherein, in use, the conduit of the first component is aligned with the conduit of the second component and a force is applied to the second component so that the projecting portion deforms an area of the first component surrounding the conduit therein so as to create a seal around the contiguous conduits of the first and second components, thus preventing any fluid from escaping as it flows from one conduit to the other conduit.   
     
     
         22 . The interconnect system of  claim 21 , for connecting a conduit in a microfluidic device to an external fluid carrying conduit. 
     
     
         23 . The interconnect system of  claim 21  wherein the interconnect system further comprises a guide positioned on the first component around the conduit therein and which mates with the projecting portion of the second component to align the conduit of the first component with the conduit of the second component. 
     
     
         24 . A microfluidic device comprising a chamber having a fluid inlet, a fluid outlet and a substrate for supporting biological material, the fluid inlet and the fluid outlet being positioned to direct fluid flowing from the fluid inlet to the fluid outlet through the chamber, and wherein the substrate forms the base of the chamber. 
     
     
         25 . The device of  claim 24 , wherein the substrate is a standard glass or polystyrene microscopy slide or culture plate and the chamber is formed on at least a portion of the substrate. 
     
     
         26 . The device of  claim 24  wherein the substrate is detachable from the device. 
     
     
         27 . The device of  claim 24 , further comprising an interconnect system which comprises: a first component having a conduit therethrough to carry fluid to the fluid inlet or away from the fluid outlet, wherein the first component is formed of a deformable material, and a second component having a projecting portion, wherein a conduit passes through the projecting portion and the second component;
 wherein the conduit of the first component is aligned with the conduit of the second component, wherein the projecting portion of the second component deforms an area of the first component surrounding the conduit therein so as to create a seal around the contiguous conduits of the first and second components, thus preventing any fluid from escaping as it flows from one conduit to the other conduit, and wherein the second component is for connecting the conduit therein to an external fluid source or sink.   
     
     
         28 . The device of  claim 27 , comprising an interconnect system for each of the fluid inlet and fluid outlet. 
     
     
         29 . The device of  claim 27  wherein the interconnect system or systems each further comprises a guide positioned on the first component around the conduit therein and which mates with the projecting portion of the second component to align the conduit of the first component with the conduit of the second component. 
     
     
         30 . A method of fabricating a microfluidic chip, the method comprising the steps of:—
 a) forming a mould defining features of the microfluidic chip; 
 b) pouring a curable polymer into the mould; 
 c) curing the polymer to form a cured polymer sheet; 
 d) releasing the cured polymer sheet from the mould; 
 e) forming a membrane having a base layer and a overlying cured polymer layer; 
 f) bonding the cured polymer sheet to the membrane; and 
 g) removing the base layer of the membrane to release the microfluidic chip. 
 
     
     
         31 . The method of  claim 30 , wherein the same curable polymer is used in steps b) and e). 
     
     
         32 . The method of  claim 30  wherein the polymer is polydimethylsiloxane (PDMS). 
     
     
         33 . The method of  claim 30 , wherein step a) is carried out by a milling process. 
     
     
         34 . The method of  claim 30  wherein the PDMS in step b) is a 10:1 base to curing agent mixture. 
     
     
         35 . The method of  claim 30  wherein a covering sheet is clamped on top of the mould prior to the curing process. 
     
     
         36 . The method of  claim 30  wherein the base layer of the membrane is a silanised silicon wafer and the overlying curable polymer layer is a PDMS layer. 
     
     
         37 . The method of  claim 36 , wherein the PDMS layer is spin coated on the silanised wafer at 500 rpm for 50 seconds to obtain a thickness of substantially 120 micrometres. 
     
     
         38 . The method of  claim 30  wherein the cured polymer is bonded to the membrane by plasma bonding. 
     
     
         39 . The method of  claim 30  wherein a microfluidic chamber is formed in the microfluidic chip following step g). 
     
     
         40 . The method of  claim 30  wherein the PDMS is cured in an oven at 80° C. for one hour.