Variable transmittance optical devices

A window comprising:

• a) a pane having a variable transmittance optical filter disposed on a first side, comprising:
• i a first substantially transparent substrate, comprising a first electrode;
• ii a second substantially transparent substrate comprising a second electrode;
• and
• iii a switching material disposed between, and operatively coupled to, the first and second electrodes, the switching material transitionable from a first light transmittance state to a second light transmittance state with application of voltage to the switching material, and transitionable from the second light transmittance state to the first light transmittance state with application of a non-electrical stimulus;
• b) an electrical system configured to receive power from an energy harvesting power source and provide a voltage to the first and second electrodes of the variable transmittance optical filter;
• and
• c) a first frame surrounding the pane, the first frame configured for slidable mounting within a second frame, the second frame configured for mounting in an existing window opening of a building.

A method for preparing a self-powered variable transmittance optical device, the method comprising:

• a) disposing a layer of switching material on a substantially transparent substrate, the switching material capable of transitioning from a light state to a dark state on exposure to UV radiation and from a dark state to a light state with application of an electric voltage, wherein a first and second electrode are disposed such that the switching material is proximate with the first and second electrodes;
• b) providing an energy-harvesting power source;
• and
• c) providing an electrical system configured to receive power from the energy harvesting power source and to provide power to the first electrode and the second electrode for application of the electric voltage through the first and second electrodes.