Bubble-based microvalve and its use in microfluidic chip

Abstract

Provided are a bubble-based microvalve and a microfluidic chip using the microvalve. Also provided are methods of using the microvalve for manipulating fluid in a microfluidic channel by changing the volume and/or location of the gas in the microvalve.

1 . A bubble-based microvalve, which microvalve comprises a gas chamber/channel connected to a fluid channel. 
     
     
         2 . The microvalve of  claim 1 , wherein the gas chamber/channel is directly connected to the fluid channel. 
     
     
         3 . The microvalve of  claim 1 , wherein the gas chamber/channel is indirectly connected to the fluid channel through a connecting channel, a gas-permeable membrane, a gas-permeable plate, or a gas-repellent film. 
     
     
         4 . The microvalve of  claim 1 , further comprising a second gas chamber/channel connected to the fluid channel. 
     
     
         5 . The microvalve of  claim 1 , wherein the gas chamber/channel comprises a drying material, and the drying material is selected from the group consisting of silica gel, calcium chloride, aluminum oxide and magnesium oxide. 
     
     
         6 - 7 . (canceled) 
     
     
         8 . A microfluidic reaction system comprising a microvalve of  claim 1 . 
     
     
         9 . The microfluidic reaction system of  claim 8 , further comprising a reaction chamber. 
     
     
         10 . The microfluidic reaction system of  claim 9 , which comprises multiple reaction chambers and multiple microvalves. 
     
     
         11 . The microfluidic reaction system of  claim 10 , wherein each microvalve is flanked by two adjacent reaction chambers, and wherein the reaction chambers are in fluidic connection with the fluidic channel. 
     
     
         12 - 13 . (canceled) 
     
     
         14 . The microfluidic reaction system of  claim 8 , wherein the size of the connecting channel is adjustable based on at least the following parameters: pressure of injection pump or injector pipette, volume of gas chamber/channel, ambient temperature, ambient humidity, air humidity inside the fluidic channel, angle of the fluidic channel and the connecting channel, surface tension of the fluidic sample, and hydrophobic property of the fluidic channel. 
     
     
         15 - 16 . (canceled) 
     
     
         17 . The microfluidic reaction system of  claim 8 , wherein the gas chambers/channels are connected by an interconnecting channel. 
     
     
         18 . The microfluidic reaction system of  claim 17 , further comprising a means to actuate and/or stop the microvalve. 
     
     
         19 . A microfluidic chip comprising a microfluidic reaction system of  claim 8 . 
     
     
         20 . The microfluidic chip of  claim 19 , further comprising a heating device capable of heating the gas chamber/channel, wherein the heating device comprises a resistance wire, a resistance film or a metal particle. 
     
     
         21 - 22 . (canceled) 
     
     
         23 . The microfluidic chip of  claim 19 , further comprising a cooling device capable of cooling the gas chamber/channel, wherein the cooling device comprises a cooling fluid. 
     
     
         24 . (canceled) 
     
     
         25 . The microfluidic chip of  claim 19 , wherein the microfluidic chip comprises a top layer and a bottom layer. 
     
     
         26 - 27 . (canceled) 
     
     
         28 . The microfluidic chip of  claim 25 , wherein the top layer contains the fluidic channel and the bottom layer contains the gas chamber/channel. 
     
     
         29 . The microfluidic chip of  claim 25 , wherein the microfluidic chip further comprises a gas-permeable membrane, a gas-permeable plate, or a gas-repellent film. 
     
     
         30 - 33 . (canceled) 
     
     
         34 . The microfluidic chip of  claim 29 , wherein the gas-permeable plate comprises pores used for connecting the gas chamber/channel. 
     
     
         35 - 37 . (canceled) 
     
     
         38 . The microfluidic chip of  claim 19 , further comprising an interconnecting channel capable of connecting the gas chambers/channels, wherein the interconnecting channel comprises gas, liquid or mixture of gas and liquid. 
     
     
         39 - 40 . (canceled) 
     
     
         41 . A method for manipulating fluid in a microfluidic channel using a microvalve of  claim 1 , wherein the volume and/or location of the gas in the microvalve is changed. 
     
     
         42 . The method of  claim 41 , wherein the microvalve is actuated by heating, and the gas chamber/channel is placed in a waterbath or in close proximity to a heater, optionally a Pt electrode. 
     
     
         43 . (canceled) 
     
     
         44 . The method of  claim 41 , wherein the microvalve is actuated by cooling, and the cooling is by injecting a cooling fluid into a channel in close proximity to the gas chamber/channel. 
     
     
         45 . (canceled) 
     
     
         46 . The method of  claim 41 , wherein the microvalve is actuated by adding a substance, such as gas, liquid or solid, into the gas chamber/channel. 
     
     
         47 - 49 . (canceled) 
     
     
         50 . The method of  claim 41 , wherein the microvalve is actuated by removing a substance from the gas chamber/channel, and the substance is removed using the second gas channel. 
     
     
         51 . (canceled) 
     
     
         52 . The method of  claim 41 , wherein the microvalve is actuated by exerting force on the gas chamber/channel, and the force leads to deformation of the gas chamber/channel. 
     
     
         53 . (canceled) 
     
     
         54 . The method of  claim 41 , wherein the microvalve is actuated by a low-humidity gas. 
     
     
         55 - 59 . (canceled)