Method of fabricating liquid film, method of arranging nano particles and substrate having liquid thin film fabricated using the same

Abstract

A method of fabricating a liquid film is provided. The method comprises the steps of applying hydrophilic liquid onto a substrate with an electrode formed thereunder, covering the hydrophilic liquid with a protection film comprising hydrophobic liquid, dispersing surfactant for reducing the surface tension between the hydrophilic liquid and the protection film, and applying voltage to the hydrophilic liquid and the electrode to wet the substrate with the hydrophilic liquid. With the surfactant and the electro-wetting principle, a contact angle between the hydrophilic liquid and the substrate is controlled. The liquid film having a uniform thickness in nano size is thus formed on the substrate. The protection film prevents the evaporation of the liquid film in the air to thereby secure the stability of the liquid film.

1 . A method of fabricating a liquid film comprising the steps of:
 applying hydrophilic liquid onto a substrate with an electrode formed thereunder;   covering the hydrophilic liquid with a protection film comprising hydrophobic liquid;   dispersing surfactant for reducing the surface tension between the hydrophilic liquid and the protection film; and   applying voltage to the hydrophilic liquid and the electrode to wet the substrate with the hydrophilic liquid.   
     
     
         2 . The method of fabricating a liquid film according to  claim 1 , wherein the surfactant is amphiphilic polymer having oleophilic group and hydrophilic group. 
     
     
         3 . The method of fabricating a liquid film according to  claim 2 , wherein the hydrophilic group of the surfactant and the hydrophilic liquid applied with voltage have polarities opposite to each other. 
     
     
         4 . The method of fabricating a liquid film according to  claim 1 , wherein the hydrophobic liquid is nonvolatile. 
     
     
         5 . The method of fabricating a liquid film according to  claim 1 , further comprising the step of heating the hydrophilic liquid to regulate the thickness thereof after the voltage-applying step. 
     
     
         6 . The method of fabricating a liquid film according to  claim 5 , wherein the hydrophobic liquid has the higher boiling point and the lower vapor pressure relative to those of the hydrophilic liquid. 
     
     
         7 . A method of arranging nano particles comprising the steps of:
 applying hydrophilic liquid containing the nano particles onto a substrate with an electrode formed thereunder;   covering the hydrophilic liquid with a protection film comprising hydrophobic liquid;   dispersing surfactant for reducing the surface tension between the hydrophilic liquid and the protection film; and   applying voltage to the hydrophilic liquid and the electrode to disperse the nano particles on the substrate.   
     
     
         8 . The method of arranging nano particles according to  claim 7 , wherein the surfactant is amphiphilic polymer having oleophilic group and hydrophilic group. 
     
     
         9 . The method of arranging nano particles according to  claim 8 , wherein the hydrophilic group of the surfactant and the hydrophilic liquid applied with voltage have polarities opposite to each other. 
     
     
         10 . The method of arranging nano particles according to  claim 7 , wherein the hydrophobic liquid is nonvolatile. 
     
     
         11 . The method of arranging nano particles according to  claim 7 , further comprising the step of heating the hydrophilic liquid to regulate the density of the nano particles after the voltage-applying step. 
     
     
         12 . The method of arranging nano particles according to  claim 11 , wherein the hydrophobic liquid has the higher boiling point and the lower vapor pressure relative to those of the hydrophilic liquid. 
     
     
         13 . The method of arranging nano particles according to  claim 12 , wherein the nano particle has a magnetic property. 
     
     
         14 . The method of arranging nano particles according to  claim 13 , further comprising the step of applying a magnetic filed between both ends of the hydrophilic liquid to arrange the nano particles parallel in the same orientation. 
     
     
         15 . The method of arranging nano particles according to  claim 14 , further comprising the step of curing the hydrophilic liquid after the nano particles-arranging step.