In electronic-paper displays, the colour of a pixel can be influenced by electrophoretically moving coloured particles in and out of the field of an observer. Apart from colour, also other (optical) properties can be influenced by moving the appropriate particles around with an external field, thereby manipulating their local concentration in a medium. One of the properties that can be tuned that way is the local refractive index, and that in turn can be used to create switchable optical effects.
We aim to uncover the potential of this phenomenon by actively manipulating the refractive index of a system with responsive colloids, aimed at switchable optical components such as lenses and gratings. Such electro-optical components can be used to enhance the functionality of LED light sources in solid state lighting applications.