Patent ID: 8816940

Claim:
An apparatus comprising: a substrate layer; a layer of colored fluid on the substrate layer, the layer of colored fluid having a thickness and a color; and a transparent actuator element on the layer of the colored fluid to modulate the thickness of the colored fluid upon being activated by a force such that the colored fluid is changed from a first state to a second state or vice versa, the modulated thickness providing a variable optical density of the colored fluid, wherein the transparent actuator element comprises a structure being a bimorph actuator, wherein, in the first state, the bimorph actuator is morphed, and the thickness of a portion of the colored fluid beneath the bimorph actuator is non-uniform, and wherein, in the second state, the bimorph actuator is flat and substantially in contact with the substrate layer, and the thickness of the portion of the colored fluid beneath the bimorph actuator in the first state is displaced to sides of the bimorph actuator.