What is Electrowetting?
Electrowetting is a microfluidic phenomena that is currently enjoying
explosive growth as a driving mechanism for a wide range of fluidic and
Electrowetting involves modifying the surface tension of liquids on a
solid surface using a voltage. By applying a voltage, the wetting properties
of a hydrophobic surface can be modified and the surface becomes increasingly
With Electrowetting displays, the modification of the surface tension
is used to obtain a simple optical switch by contracting a colored oil
film electrically. Without a voltage, the colored oil forms a continuous
film and the color is visible to the consumer. When a voltage is applied
to the display pixel the oil is displaced and the pixel becomes transparent.
When different pixels are independently activated, the display can show
content like an photograph or a video.
We can also use this transmissive pixel as the basis for reflective of
The high switching speed (a few milliseconds) of electrowetting and its
applicability to small (pixel) dimensions means that electrowetting is
ideally suited for application to displays showing video content.