Fluid analysis with fluid seal system

Abstract

In one example in accordance with the present disclosure, a fluid analysis system is described. The fluid analysis system includes an inlet channel to an analysis chamber. The analysis chamber is to receive a fluid sample to be analyzed. The fluid analysis system also includes a fluid branch having a fluidic junction along the inlet channel and a gas chamber to house a volume of trapped gas, the gas chamber being in fluid communication with the fluid branch. The fluid analysis system also includes a sealing fluid delivery system to fill the fluid branch with a sealing fluid and a heater adjacent the gas chamber to heat the gas chamber such that the trapped gas expands to push the sealing fluid into the inlet channel to seal the analysis chamber.

1 . A fluid analysis system, comprising:
 an inlet channel to an analysis chamber, wherein the analysis chamber is to receive a fluid sample to be analyzed;   a fluid branch having a fluidic junction along the inlet channel;   a gas chamber to house a volume of trapped gas, the gas chamber being in fluid communication with the fluid branch;   a sealing fluid delivery system to fill the fluid branch with a sealing fluid; and   a heater adjacent the gas chamber to heat the gas chamber such that the trapped gas expands to push the sealing fluid into the inlet channel to seal the analysis chamber.   
     
     
         2 . The fluid analysis system of  claim 1 , further comprising a first capillary break at the fluidic junction to prevent the sealing fluid from entering the inlet channel prior to heating the gas chamber. 
     
     
         3 . The fluid analysis system of  claim 2 , further comprising a second capillary break in the fluid branch upstream of the gas chamber to prevent backflow of the sealing fluid through the fluid branch. 
     
     
         4 . The fluid analysis system of  claim 3 , wherein the second capillary break has a smaller opening than the first capillary break. 
     
     
         5 . The fluid analysis system of  claim 3 , wherein the second capillary break has different characteristics as compared to the first capillary break. 
     
     
         6 . The fluid analysis system of  claim 5 , wherein a characteristic that is different between the second capillary break and the first capillary break is selected from the group consisting of:
 a length;   a width;   a capillary break gap;   a holding pressure; and   a hydrophobicity.   
     
     
         7 . The fluid analysis system of  claim 1 , further comprising a gas chamber capillary break to prevent the sealing fluid from entering the gas chamber. 
     
     
         8 . The fluid analysis system of  claim 1 , wherein the sealing fluid has a lower vapor pressure than the fluid sample and is immiscible with the fluid sample. 
     
     
         9 . The fluid analysis system of  claim 1 , further comprising a number of actuators to transport the sealing fluid and the fluid sample throughout the fluid analysis system. 
     
     
         10 . A method, comprising:
 introducing a sealing fluid through a fluid branch to a fluidic junction with an inlet channel of an analysis chamber;   introducing a fluid sample into the analysis chamber via the inlet channel;   heating trapped gas in a gas chamber that is in fluid communication with the fluid branch; and   via expansion of the trapped gas in the gas chamber, transporting the sealing fluid into a body of the inlet channel to seal the analysis chamber and prevent evaporation from the analysis chamber.   
     
     
         11 . The method of  claim 10 , wherein the sealing fluid is selected from the group consisting of:
 silicon oil;   mineral oil;   hexadecane;   a hydrofluoroether-based fluid; and   a fluorocarbon-based fluid.   
     
     
         12 . The method of  claim 10 , further comprising preventing:
 the sealing fluid from entering the body of the inlet channel until the gas chamber is heated;   flow of the sealing fluid into the gas chamber; and   backflow of the sealing fluid through the fluid branch.   
     
     
         13 . A fluid analysis system, comprising:
 an analysis chamber having an inlet channel and an outlet channel;   a first fluid branch having a fluidic junction along the inlet channel;   a second fluid branch having a fluidic junction along the outlet channel;   a first gas chamber in fluid communication with the first fluid branch;   a second gas chamber in fluid communication with the second fluid branch;   a sealing fluid delivery system to fill the first fluid branch and second fluid branch with a sealing fluid; and   a heating system to heat the first gas chamber and the second gas chamber such that trapped gas expands to push the sealing fluid into the inlet channel and outlet channel.   
     
     
         14 . The fluid analysis system of  claim 13 , wherein the first gas chamber and first fluid branch have different properties than the second gas chamber and second fluid branch, respectively. 
     
     
         15 . The fluid analysis system of  claim 13 , wherein the sealing fluid delivery system comprises a shared sealing reservoir between the first fluid branch and the second fluid branch.