Photonic Ink Changes Color On Command

An anonymous reader submits "According to Nature's report : "A new ink changes colour at the flick of a switch." It now named Photonic Ink, or P-Ink. "P-Ink's iridescent colours depend upon a process called diffraction." "To make the colour of the ink tunable" the team led by Geoffrey Ozin "packs a polymer gel between its stacked spheres" which can change size "when it is soaked in solvent and shrinks when it dries". In addition, it "conducts electricity", and "altering the voltage tunes the ink's colour smoothly through the spectrum." more detail also can found on Advanced Materials."