The next time you buy a cell phone, take a close look at the display panel. If things go the way Qualcomm hopes, that colorful little rectangle could give a whole new meaning to the expression “butterfly effect.” True, the interferometric modulator (IMOD) displays recently introduced by the San Diego–based firm have nothing to do with the unexpectedly strong effect a wing beat can theoretically have on the weather. But the devices do use an array of artificial microstructures to produce the same kind of iridescent colors as are seen on the wings of tropical butterflies. And Qualcomm is betting that its approach will give IMODs several advantages over today’s dominant liquid-crystal-display (LCD) technology.