COLORED CONDUCTIVE FLUIDS FOR ELECTROWETTING AND ELECTROFLUIDIC TECHNOLOGIES

摘要

Colored conductive fluids for electrowetting or electrofluidic devices, and the devices themselves, are disclosed. The colored conductive fluid includes a polar solvent and a colorant selected from a pigment and/or a dye. The polar solvent has (a) a dynamic viscosity of 0.1 cP to 1000 cP at 25° C., (b) a surface tension of 25 dynes/cm to 90 dynes/cm at 25° C., and (c) an electrowetting relative response of 20% to 80%. The colored conductive fluid itself can have an electrical conductivity from 0.1μS/cm to 3,000μS/cm and can have no greater than 500 total ppm of monatomic ions with ionic radii smaller than 2.0Åand polyatomic ions with ionic radii smaller than 1.45Å. The colored conductive fluid should not cause electrical breakdown of a dielectric in the device in which it is employed. An agent for controlling electrical conductivity can optionally be added to the colored conductive fluid.