That’s not a farfetched idea, insists Frank Shiu, deputy division director of Taiwan’s Industrial Technology Research Institute’s (ITRI) Display Technology Center. Shiu is working with using electrowetting displays as window glass. This technology relies on transparent honeycombs of glass or plastic that contain droplets of colored liquid in each compartment. Electronics on the edges of the display control the behavior of the droplets, contracting them down so they are nearly invisible, or expanding them to cover their compartment with color; researchers around the world are working on the technology with an eye on the e-book market.
Shiu and his team have a ways to go before electrowetting technology starts replacing ordinary window glass. In particular, they’ve got to figure out how to make it cheaper, right now, adding the necessary electrodes and pigment to window glass costs about US$10 for 39 cm2 inches; that means glass for an average window would cost around $200. And that doesn't include the cost of the control electronics or the solar cells that would power the systems.
ITRI estimates that the price can come down to $60 for 1 m2 as the manufacturing process improves, for the materials involved aren’t particularly expensive. Shiu envisions these windows replacing shades and blinds, with early versions custom made to match room décor, and later versions able to display images, for example, details about products in store windows.
Tekla S. Perry is a senior editor at IEEE Spectrum. Based in Palo Alto, Calif., she's been covering the people, companies, and technology that make Silicon Valley a special place for more than 40 years. An IEEE member, she holds a bachelor's degree in journalism from Michigan State University.