Variable transmission optical filter based on an actuated origami structure

A variable transmission thin film for visible light is proposed based on a mechanically actuated origami structure coated with metallic nanoparticles. The transmissivity can be tuned continuously from 0 to >90% for unpolarized incident light. Power is only required for switching and is not necessary to maintain the desired transmittance state. The asymmetric metal nanorods create two distinct plasmon resonances. Controlling the orientation of the nanorods with respect to the direction of the incident light changes the optical transmittance. The switching speed is only limited by the mechanical actuation and not by the optical response of the materials. The applicability of the proposed film for smart glass applications is investigated. Good image transmission clarity with minimal distortion is shown.