Active aerosols.

We report the dynamics and control of the orientational and positional order of ensembles of gold nanorods suspended in air at standard temperature and pressure using externally applied electric fields, demonstrating an active aerosol. Light filter, valve and gradient responses are shown, establishing active aerosols as a unique type of optical element we term component-less optics.

VO-based switchable radiator for spacecraft thermal control.

Direct calorimetric measurements of a solid state passive switchable radiator for spacecraft thermal control have been performed in a simulated space environment. Dynamic emissivity control is provided by the thermochromic phase change in a multilayer VO thin film based resonant absorber. The measured radiated power difference between 300 K and 373 K was 480 W/m corresponding to a 7× difference in radiative cooling power.