Patent ID: 8760750

Claim:
A thermally switchable device for use in a building or vehicle for regulating transmission and absorption of solar radiant energy incident on the building or vehicle, the device comprising two absorptive polarizers oriented with respect to each other such that respective polarization directions of the absorptive polarizers are orthogonal; and a thermotropically-actuated liquid crystal positioned between the two absorptive polarizers that transitions between an ordered, twisted nematic state and a disordered, isotropic state at a threshold surface temperature caused by solar heating of the device, wherein the liquid crystal has an insignificant effect on incident solar energy in the isotropic state and acts as a depolarizer in the twisted nematic state to rotate a first polarity of solar radiant energy passing through a first of the absorptive polarizers to a second polarity oriented to pass through a second of the absorptive polarizers.