Adaptive Thermochromic Windows from Active Plasmonic Elastomers

Architectural windows that smartly regulate the indoor solar irradiation are promised to economize the building energy consumption. Here, we demonstrate a method for adaptive, broadband, and highly efficient solar modulation for energy-efficient smart windows through active plasmonics in reconfigurable structures. We develop a kirigami-inspired elastomer containing plasmonic vanadium dioxide (VO2) nanoparticles, in which the geometrical transition and the temperature-dependent localized surface plasmon resonance (LSPR) present dominant controls in ultraviolet-visible and near-infrared regions, respectively. The active LSPR control, via stretch-induced local dielectric changes is mitigated on reconfigurable metamaterials because of their unique strain distributions. This method demonstrated a desirable property in energy-efficient smart windows facilitating improved solar energy modulation (37.7%), surpassing the best-reported modulation in passive and transparent VO2 thermochromism systems. This first attempt to integrate the plasmonics and reconfigurable structures may inspire developments in smart windows, building energy economization, as well as fundamental studies of plasmonic controls in metastructures.