Smart sunglasses for enhanced safety and comfort
Smart devices are those that change their properties in response to stimuli. For example, electrochromic smart devices change colour in response to current or voltage. Electrochromic glass can control the amount of light and heat passing through the material and has found wide application in windows, skylights, cars and museum display cases among others. Current state-of-the-art inorganic-organic (hybrid) nanocomposites used in electrochromic devices still face obstacles related to cost, colouration efficiency and compatibility with plastic substrates, to name but a few. European researchers set out to develop new cost-effective hybrid electrochromic coatings with improved electro-optical properties and durability for all-plastic smart electrochromic devices. In particular, the ‘Nanocomposites with high colouration efficiency for electrochromic smart plastic devices’ (Nanoeffects) project focused on electrochromic films for smart sunglasses. Researchers successfully developed a novel conducting nanocomposite coating that changed its optical properties within seconds of stimulation. It was essentially colourless and transparent in the bleached state (of critical importance to the ophthalmic sector) and compatible with lightweight and impact-resistant plastic substrates. This represents a major breakthrough in smart shading technology. In addition, film preparation relied on highly cost- and energy-efficient processing steps. Commercialisation of Nanoeffects project outcomes, not only for use in sunglasses but for many other applications in which it is desirable to control the degree of visible or infrared light transmitted, has important implications for the European economy as well as the safety and comfort of EU citizens.