LAUSR

Flat glass is clear while frosted glass with a microrough surface appears translucent by light scattering. Motivated by this optical surface scatterer, a transparent soft media with electrically tunable surface roughness could make a low-cost smart window. Recently, a dielectric elastomer actuator with microwrinkled transparent compliant electrodes was proposed to make such a smart window, but its active microwrinkled area occupied only a small fraction of the window device, as it needs room for large-strain unfolding. To solve this issue, this paper first shows transparent-to-translucent switching by a low-strain-induced microwrinkling and the reverse by electric-field-induced unfolding. This is possible by using an electrically tunable optical surface scatterer that consists of a TiO2 nanometric thin film of high modulus and high refractive index that is sandwiched between a nanometric conductive overcoat of transparent conductive polymer, that is, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)...