Static Electrowetting

Several theoretical descriptions have been proposed to describe the electric field-induced change in the macroscopic liquid-solid contact angle in static electrowetting. These are based on thermodynamic, molecular kinetic, electromechanic, and static approaches [2]. Vallet et al. [7] and Kang [9] considered an infinite planar wedge analysis in the three-phase contact line region, as shown in Fig. 4. As the top... 

Electrowetting-on-dielectric (EWOD) Electrowetting on insulator-coated electrodes (EICE) Electrowetting on line electrodes (ELE) Spontaneous electrowetting Static electrowetting... 

Electrowetting, Applications, Fig. 1 Schematic illustration of (a) static electrowetting in which the applied electric field induces a macroscopic change in the contact angle and (b) spontaneous electrowetting in which a thin... 

Electrowetting, Applications, Fig. 2 Schematic depiction of a typical static electrowetting setup for drop actuation in a microfluidic device... 

Practical static electrowetting schemes typically involve the use of a patterned array of multiple electrodes, each of which can be individually controlled, as shown in Fig. 2 note that the use of a wire electrode in contact with the drop in the usual EWOD/EICE setup in Fig. la is impractical due to the moving drop. The drop should also span across two electrodes at any one time to facilitate continual discrete motion [7] the smallest liquid volume that can be manipulated is therefore constrained by the electrode size. 

Other microfluidic components have also been developed using static electrowetting. An electrowetting-actuated valve was proposed by Cheng and Hsiung [10]. A hydrophobic layer comprising plasma-modified poly... 

Electrowetting, Applications, Fig. 4 Drop dispensing or metering from a reservoir using static electrowetting schemes (From Ref. [9])... 

Another interesting electro-optical application that has been developed using static electrowetting is in display technology. This idea was initially proposed in the 1980s by... 

Another interesting electro-optical application that has been developed using static electrowetting is in display technology. This idea was initially proposed in the 1980s by Beni and Hackwood [29] although a demonstrable prototype concept was only produced in 2003 by Hayes and Feenstra [30]. The principle is illustrated in Fig. 10a. A dyed oil drop under a transparent aqueous solution is... 

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