Fluid Transfer Apparatus

Abstract

The invention relates to an apparatus for transporting a fluid, an object to be transported, in the vertical or horizontal direction. More particularly, the apparatus of the present invention has a surface formed into a pattern recursively alternating in a fluid transfer direction such that the surface of the apparatus has a contact angle different from that of the fluid, and the transportation of the fluid is controlled by the hydrodynamic force generated by the difference of the contact angles.

1 . An apparatus for transferring a fluid, an object to be transferred, the apparatus comprising a surface having surface sections formed into a pattern recursively alternating in a fluid transfer direction such that the surface sections have different contact angles with the fluid, wherein the fluid transport is controlled by the hydrodynamic force generated by the difference of the contact angles. 
     
     
         2 . The apparatus according to  claim 1 , wherein the surface sections composed by the local variation of contact angles with the fluid have a fluid sliding angle ranging between 0° and 5°. 
     
     
         3 . The apparatus according to  claim 2 , wherein the surface is formed with repeated pattern having a toothed form with continuously changed contact angle on the tooth surface. 
     
     
         4 . The apparatus according to  claim 2 , wherein the surface is an inner surface of a tube, which includes closed type surface bands connected at opposite ends or helical surface sections recursively alternating with each other, wherein the bands or the helical surface sections respectively have different contact angles with the fluid. 
     
     
         5 . The apparatus according to  claim 4 , wherein a step is formed between the bands or the surface sections having different contact angles. 
     
     
         6 . The apparatus according to  claim 5 , wherein the surface section having a high contact angle with the fluid has a curvature. 
     
     
         7 . The apparatus according to  claim 4 , wherein the tube has a diameter ranging between 100 μm and 2000 μm. 
     
     
         8 . The apparatus according to  claim 7 , wherein the width of the band or helical surface section has a range of 0.0001 to 5 times the diameter of the tube. 
     
     
         9 . The apparatus according to  claim 8 , wherein the width of the surface section having a high contact angle with the fluid is smaller than that of the surface section having a low contact angle with the fluid. 
     
     
         10 . The apparatus according to  claim 7 , wherein the helical surface section has a dihedral angle of a range between 20° and 70° along the helical axis. 
     
     
         11 . The apparatus according to  claim 6 , wherein the height of the bands or helical surfaces protruding along the center of the tube has a range of 0.0001 to 0.01 times the diameter of the tube. 
     
     
         12 . The apparatus according to  claim 1 , wherein the fluid is water. 
     
     
         13 . The apparatus according to  claim 12 , wherein the surface having different contact angles with the fluid includes a hydrophobic surface and a super-hydrophobic surface. 
     
     
         14 . The apparatus according to  claim 13 , wherein the hydrophobic surface and the super-hydrophobic surface respectively are a polymer surface. 
     
     
         15 . The apparatus according to  claim 14 , wherein the superhydrophobic surface is formed by directly irradiating ultrafast laser beams onto the polymer surface or replication by utilizing other solid mold having alternative hydrodynamic surface properties. 
     
     
         16 . The apparatus according to  claim 15 , wherein the polymer surface is a poly(dimethylsiloxane) (PDMS) surface.