Electrowetting display

Abstract

The present invention comprises construction of a display from display elements that are actuated using the physical principle of electrowetting. In one embodiment, pores within porous silicon are filled with an ionic and an optically reflective electronic conductor, and actuated by application of an electric potential across the pore. An image is then formed on an array of such pores by applying an appropriate voltage to each pore of the array to create an optical image in the light reflected off the electronic conductors. Such a display may be constructed to have very high resolution, making it desirable for creating real-time holographic images, or for creating high-resolution mask images for use in photolithography.

1 . A method of operating a display comprising: 
 applying a voltage across an electrowetting display element;    migrating an ionic fluid within the display element between an electronic conductive fluid and a display element wall;    migrating a reflective electronic conductive fluid within the electrowetting display element in a direction opposite the ionic fluid migration; and    reflecting light off the reflective electronic conductive fluid to create an optical image.    
     
     
         2 . The method of  claim 1  wherein the ionic fluid is saltwater.  
     
     
         3 . The method of  claim 1  wherein the reflective electronic conductive fluid is mercury.  
     
     
         4 . The method of  claim 1  further comprising generating light that is reflected off the reflective electronic conductive liquid.  
     
     
         5 . The method of  claim 1 , wherein the electrowetting display element is formed in porous silicon.  
     
     
         6 . A method of forming a holographic image, comprising: 
 applying a voltage across an electrowetting display element within a display, the electrowetting display elements forming a display having a matrix of elements with at least 1000 lines of pores per millimeter;    migrating an ionic fluid within the display element between an electronic conductive fluid and a display element wall;    migrating a reflective electronic conductive fluid within the electrowetting display element in a direction opposite the ionic fluid migration; and    reflecting light off the reflective electronic conductive fluid to create an optical image.    
     
     
         7 . The method of forming a holographic image of  claim 6 , wherein the matrix of electrowetting display elements is formed in porous silicon.  
     
     
         8 . The method of forming a holographic image of  claim 7 , wherein an interior surface of the display element pores of the porous silicon is oxidized to increase surface resistance.  
     
     
         9 . The method of forming a holographic image of  claim 6 , wherein the ionic fluid is saltwater.  
     
     
         10 . The method of forming a holographic image of  claim 6 , wherein the reflective electronic conductive fluid is mercury.  
     
     
         11 . The method of forming a holographic image of  claim 6 , further comprising generating light that is reflected off the reflective electronic conductive liquid.  
     
     
         12 . A method of fabricating a display comprising: 
 fabricating a substrate of insulating material with at least one flat surface;    forming a matrix of pores extending from the flat surface into the substrate;    injecting an ionic conductive liquid and a reflective electronic conductive liquid into each of the pores in the matrix of pores;    capping each pore of the matrix of pores with a transparent conductive cap.    
     
     
         13 . The method of fabricating a display of  claim 12 , wherein the transparent conductive cap comprises Indium tin oxide.  
     
     
         14 . The method of fabricating a display of  claim 12 , wherein the ionic conductive liquid comprises a saltwater solution.  
     
     
         15 . The method of fabricating a display of  claim 12 , wherein the reflective electronic conductive liquid comprises mercury.  
     
     
         16 . The method of fabricating a display of  claim 12 , wherein the substrate comprises porous silicon.  
     
     
         17 . The method of fabricating a display of  claim 16 , wherein the porous silicon comprises greater than 1000 lines per millimeter of pores.  
     
     
         18 . The method of fabricating a display of  claim 16 , further comprising oxidizing an inner surface of the pores in the porous silicon substrate.  
     
     
         19 . The method of fabricating a display of  claim 12 , further comprising forming actuating conductors operable to electrically couple the pores to receive an actuation signal.  
     
     
         20 . The method of fabricating a display of  claim 19 , further comprising electrically coupling the pores to electronic control circuitry via the actuating conductors.