Electrowetting

The electrowetting of mercury and other liquids on variably charged surfaces was probably first explained by Gabriel Lippmann in 1875[1] and was certainly observed much earlier.

[2] The term electrowetting was first introduced in 1981 by G. Beni and S. Hackwood to describe an effect proposed for designing a new type of display device for which they received a patent.

Brown in 1980 and later funded in 1984–1988 under NSF Grants 8760730 & 8822197,[4] employing insulating dielectric and hydrophobic layer(s) (EWOD), immiscible fluids, DC or RF power; and mass arrays of miniature interleaved (saw tooth) electrodes with large or matching indium tin oxide (ITO) electrodes to digitally relocate nano droplets in linear, circular, and directed paths, pump or mix fluids, fill reservoirs, and control fluid flow electronically or optically.

Silver at the NIH, EWOD-based electrowetting was disclosed for single and immiscible fluids to move, separate, hold, and seal arrays of digital PCR sub-samples.

[18] The electrowetting effect has been defined as "the change in solid-electrolyte contact angle due to an applied potential difference between the solid and the electrolyte".

While it is possible to obtain a detailed numerical model of electrowetting by considering the precise shape of the electrical fringing field and how it affects the local droplet curvature, such solutions are mathematically and computationally complex.

It was recently shown by Klarman et al.[21] that contact angle saturation can be explained as a universal effect- regardless of materials used – if electrowetting is observed as a global phenomenon affected by the detailed geometry of the system.

Taking advantage of the negligible contact line pinning at the liquid-liquid interface, the droplet response in EWOLF can be electrically addressed with enhanced degree of switchability and reversibility compared to the conventional EWOD.

Moreover, the infiltration of liquid lubricant phase in the porous membrane also efficiently enhances the viscous energy dissipation, suppressing the droplet oscillation and leading to fast response without sacrificing the desired electrowetting reversibility.

By optically modulating the number of carriers in the space-charge region of the semiconductor, the contact angle of a liquid droplet can be altered in a continuous way.

These fluoropolymers coat the necessary conductive electrode, typically made of aluminum foil or indium tin oxide (ITO), to create the desired electrowetting properties.

[34] The previous hosts of the electrowetting meeting are: Mons (1999), Eindhoven (2000), Grenoble (2002), Blaubeuren (2004), Rochester (2006), Los Angeles (2008), Pohang (2010), Athens (2012), Cincinnati (2014), Taipei (2016).