Chameleon Liquid Could Replace LCDs

NewScientist reports on a color-changing liquid that could cheaply replace the color components of standard LCDs. According to researchers at UC Riverside, the liquid 'contains tiny iron oxide particles coated with plastic. It is cheap and easy to make, and could also be used in flexible, rewritable, electronic paper.' From the article: 'The opposing forces of electrostatic repulsion [in the plastic] and magnetic attraction [in the iron oxide] result in the particles arranging themselves into an ordered structure, known as a colloidal 'photonic crystal'. The colloidal crystal reflects light because the spacing between neighboring particles in the structure is equivalent to the wavelength of light. Also, tuning the spacing slightly alters the exact wavelength, or colour, of light that is reflected. This can easily be done by varying the strength of the magnetic field applied to the crystal.