Filler Fluids for Droplet Operations

Abstract

The present invention relates to filler fluids for droplet operations. According to one embodiment of this aspect, a droplet microactuator including an opaque filler fluid and a transparent droplet thereon is provided. The droplet microactuator may further include a first substrate comprising electrodes configured to effect electrowetting mediated droplet operations on a surface of the first substrate; a second substrate spaced apart from the surface of the first substrate by a distance sufficient to define an interior volume between the first substrate and second substrate; and wherein the droplet and the filler fluid are in the interior volume, and wherein the droplet is surrounded by the filler fluid and arranged with respect to the electrodes in a manner which permits electrowetting mediated droplet operations to be effected on the droplet using the electrodes.

We claim: 
     
         1 . A droplet microactuator comprising an opaque filler fluid and a transparent droplet thereon. 
     
     
         2 . The droplet microactuator of  claim 1  further comprising:
 (a) a first substrate comprising electrodes configured to effect electrowetting mediated droplet operations on a surface of the first substrate; 
 (b) a second substrate spaced apart from the surface of the first substrate by a distance sufficient to define an interior volume between the first substrate and second substrate; and 
 (c) wherein the droplet and the filler fluid are in the interior volume, and wherein the droplet is surrounded by the filler fluid and arranged with respect to the electrodes in a manner which permits electrowetting mediated droplet operations to be effected on the droplet using the electrodes. 
 
     
     
         3 . The droplet microactuator of  claim 1  wherein the filler fluid comprises an oil. 
     
     
         4 . The droplet microactuator of  claim 1  wherein the filler fluid comprises a surfactant. 
     
     
         5 . The droplet microactuator of  claim 1  wherein the filler fluid comprises an oil and a surfactant. 
     
     
         6 . The droplet microactuator of  claim 1  wherein the filler fluid comprises one or more silicone oils. 
     
     
         7 . The droplet microactuator of  claim 1  wherein the filler fluid comprises one or more fluorosilicone oils. 
     
     
         8 . The droplet microactuator of  claim 1  wherein the filler fluid comprises one or more hydrocarbons. 
     
     
         9 . The droplet microactuator of  claim 1  wherein the filler fluid comprises one or more alkanes. 
     
     
         10 . The droplet microactuator of  claim 1  wherein the filler fluid comprises a component selected from the group consisting of decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane. 
     
     
         11 . The droplet microactuator of  claim 1  wherein the filler fluid comprises a component selected from the group consisting of aromatic alkanes. 
     
     
         12 . The droplet microactuator of  claim 1  wherein the filler fluid comprises a mineral oil. 
     
     
         13 . The droplet microactuator of  claim 1  wherein the filler fluid comprises a paraffin oil. 
     
     
         14 . The droplet microactuator of  claim 1  wherein the filler fluid is solid at room temperature of about 25° C. 
     
     
         15 . The droplet microactuator of  claim 1  further comprising a second filler fluid surrounding or in contact with the filler fluid. 
     
     
         16 . The droplet microactuator of  claim 4  wherein the surfactant comprises nonionic low hydrophile-lipophile balanced (HLB) surfactant. 
     
     
         17 . The droplet microactuator of  claim 16  wherein the HLB is less than about 10. 
     
     
         18 . The droplet microactuator of  claim 16  wherein the HLB is less than about 5. 
     
     
         19 . The droplet microactuator of  claim 4  wherein the surfactant is a nonionic low HLB surfactant or a nonionic lipophilic surfactant. 
     
     
         20 . The droplet microactuator of  claim 4  wherein the droplet comprises whole blood and the surfactant has an HLB which is less than about 2. 
     
     
         21 . The droplet microactuator of  claim 5  wherein the oil comprises a silicone oil and the surfactant comprises nonionic lipophilic surfactant 
     
     
         22 . The droplet microactuator of  claim 5  wherein the surfactant is provided in an amount which ranges from about 0.001 to about 10% w/w. 
     
     
         23 . The droplet microactuator of  claim 5  wherein the surfactant is provided in an amount which ranges from about 0.001 to about 1% w/w. 
     
     
         24 . The droplet microactuator of  claim 5  wherein the surfactant is provided in an amount which ranges from about 0.001 to about 0.1% w/w. 
     
     
         25 . The droplet microactuator of  claim 5  wherein the filler fluid comprises silicone oil and the surfactant is nonionic lipophilic surfactant in an amount which ranges from about 0.001 to about 10% w/w. 
     
     
         26 . The droplet microactuator of  claim 5  wherein the filler fluid comprises silicone oil and the surfactant is nonionic lipophilic surfactant in an amount which ranges from about 0.001 to about 1% w/w. 
     
     
         27 . The droplet microactuator of  claim 5  wherein the filler fluid comprises silicone oil and the surfactant is nonionic lipophilic surfactant in an amount which ranges from about 0.001 to about 0.1% w/w. 
     
     
         28 . A droplet microactuator comprising:
 (a) a first substrate comprising electrodes configured to effect electrowetting mediated droplet operations on a surface of the first substrate;   (b) a second substrate spaced apart from the surface of the first substrate by a distance sufficient to define an interior volume between the first substrate and the second substrate; and   (c) a transparent droplet and an opaque filler fluid in the interior volume, wherein the droplet is surrounded by the filler fluid and fills the interior volume surrounding the droplet, and the droplet arranged with respect to the electrodes in a manner which permits electrowetting mediated splitting, merging, or dispensing of the droplet using the electrodes, wherein the filler fluid comprises an oil and a surfactant.   
     
     
         29 . The droplet microactuator of  claim 28  wherein the droplet has a discoid shape.