The surface of a bubble is a beautiful display of light and movement. Now displays may be made of bubbles.
Created by a research team from three universities - Carnegie Mellon, the University of Tokyo and University of Tsukuba - the bubble displays could be used to make three-dimensional images and duplicate the "look" of textures more realistically than current flat screen technology.
The bubble displays are made from a mixture of water, sugar, glycerin, soap, a surfactant and milk - a combination known as a colloidal liquid.
The scientists used this odd-sounding brew because colloidal liquids make membranes strong enough that they don't pop like soap bubbles do. It's even possible to pass an object through them. Colloidal liquids also show the Tyndall Effect, which refers to the way that some wavelengths of light get scattered more than others, giving bubbles their opalescence.
To make the images, the researchers used ultrasonic sound waves, which change the perfectly smooth surface of the liquid membrane from transparent to reflective or opaque. The control is fine enough that one can change the properties of small parts of the membrane, and thus get an image.