Electochromic

•When electric current is applied, opacity changes between

–Opaque

–Transparent state

•Requires no electrical current to maintain current phase

•Electricity begins at the edge and works in slowly, can take a few seconds to several minutes depending on size

•Maintains some visibility for outside contact even in its opaque state

•Used in rearview mirrors, windows protecting displays of art from UV and even interior light damage

•Recently developing electrochromic glass that is reflective rather than absorptive to make a mirror-like surface

•Also developing electochromic displays which would be 30 micrometers thick (1/3 of human hair) using nano-crystaline films layered to serve individual functions (contrast, color etc).  Runs on around  1 volt of energy, but cannot display more than change in color yet