Electrowetting cell and method of manufacturing thereof

Abstract

The electrowetting cell ( 15 ) comprises an outer wall ( 90 ) and an inner wall ( 80 ), said outer wall ( 90 ) being provided with extensions ( 85, 86 ) extending at opposing sides of the inner wall ( 80 ). The cell ( 15 ) is further provided with a membrane ( 45 ) for volume expansion and is sealed through an electroplated layer ( 95 ).

1 . An electrowetting cell comprising a body section provided with a substrate and at least one side wall, which substrate and side wall jointly define a cavity containing electrowetting fluids and further comprising at least one end section securable to the body section, wherein the at least one side wall of the body section comprises an inner wall and an outer wall, wherein a portion of which end section is part of the inner wall, the outer wall securing the end section and the body section by means of extensions extending at a first and a second side of the outer cell over opposed sides of the inner wall.  
     
     
         2 . An electrowetting cell as claimed in  claim 1 , wherein the inner wall comprises a portion of the substrate.  
     
     
         3 . An electrowetting cell as claimed in  claim 2 , wherein the inner wall further comprises a spacer of an electrically insulating material between said portion of the substrate and said portion of the end section.  
     
     
         4 . An electrowetting cell as claimed in  claim 1 , wherein the extension of the outer wall extending at the first side of the inner wall is a clamping body that is attached to the outer wall.  
     
     
         5 . An electrowetting cell as claimed in  claim 4 , wherein the clamping body is attached to the outer wall by means of a metal layer that is grown on the extension and on the outer wall.  
     
     
         6 . An electrowetting cell as claimed in  claim 1 , wherein a first and a second electrode that are in contact with at least one of the electrowetting fluids are defined at opposed sides of the cavity at the substrate and at the end section.  
     
     
         7 . An electrowetting cell as claimed in  claim 6 , wherein the substrate is provided with an aperture, at an end of which said electrode is present.  
     
     
         8 . An electrowetting cell as claimed in  claim 1 , wherein the end section comprises a flexible membrane allowing for volume expansion of the closed cavity.  
     
     
         9 . An electrowetting cell as claimed in  claim 2 , wherein the extension at the second side of the inner wall is attached to the substrate through a metal layer that is grown on both.  
     
     
         10 . An electrowetting cell comprising a body section provided with a substrate and at least one side wall, which substrate and side wall jointly define a cavity containing electrowetting fluids and further comprising at least one end section secured to the body section, wherein the end section is attached to the body section with a metal layer that is applied on a surface of both the end section and the joint section.  
     
     
         11 . An electrowetting cell as claimed in  claim 1 , comprising an overlapping a part of the outer wall and in the inner wall or the substrate or end section, wherein in the overlapping part at least one of the adjacent surfaces comprises a sealant for sealing the overlapping part under pressure.  
     
     
         12 . An electrowetting cell as claimed in  claim 11 , wherein the sealant comprises an organic composite, such as a composite comprising a plastic or rubber.  
     
     
         13 . An electrowetting cell as claimed in  claim 11 , wherein the sealant has electrically conductive properties.  
     
     
         14 . An electrowetting cell as claimed in  claim 11 , wherein the sealant comprises a nickel-PTFE composite, such as niflon.  
     
     
         15 . An electrowetting cell as claimed in  claim 11 , wherein in the sealant is obliged by means of a depositing or growth process.  
     
     
         16 . A method of manufacturing an electrowetting cell comprising a body section provided with a substrate and a side wall having an inner wall and an outer wall, said outer wall being provided with a first and a second extension extending at opposed sides of the inner wall, which substrate and side wall jointly define a cavity containing a first and a second electrowetting fluid, which method comprises the steps of: 
 providing an outer wall and a substrate, resulting in the cavity;    filling the cavity with the first and the second electrowetting fluid;    providing the end section in the cavity such that it is immersed in at least one of the fluids at a desired distance to the substrate, portions of the substrate and the end section and optionally an intermediate spacer forming the inner wall;    securing the end section to the body section in that the first extension of the outer wall is positioned on top of the end section.    
     
     
         17 . A method as claimed in  claim 16 , wherein the extension is a separate clamping body that is connected to the outer wall only after having been positioned on the end section.  
     
     
         18 . A method as claimed in  claim 17 , wherein the clamping body and the outer wall are connected with a metal layer grown on their surfaces.  
     
     
         19 . An image capture device or an image sensor incorporating an electrowetting cell as claimed in  claim 1 .  
     
     
         20 . An optical scanning device comprising an electrowetting cell as claimed in  claim 1 .  
     
     
         21 . A display device incorporating an electrowetting cell as claimed in  claim 1.