Electrowetting: Mixing Water And Electricity

Introduction to Electrowetting

Gabriel Lippmann first published his work on electrocapillarity, the basis of modern electrowetting on dielectric, in 1875¹. Lippmann observed that the meniscus of mercury in a capillary tube could be modified with the application of a small electric potential.² It was found that the same process could not be performed with water as, upon application of a potential difference across electrodes submerged in water, electrolysis occurs.

The advancement of electrowetting came with the introduction of a dielectric material to separate the water from one of the electrodes³. A water droplet is disposed on, for example, a dielectric film and, on application of a voltage across the droplet and film, flattening of the water droplet occurs. The below figure shows a schematic diagram of an electrowetting on dielectric setup.