Electrochromic devices on polyester foil

We report on a new flexible electrochromic foil device with sufficient optical modulation range, dynamics, and durability for practical uses. The device incorporates a film of W oxide made by sputtering in the presence of hydrogen, another film of Ni–V oxide made by sputtering and postdeposition treatment in ozone, and a polymer laminate. Applications as variable-transmittance visors in motorcycle helmets are discussed.