Devices having selectively permeable barriers are provided with a substrate, a first layer overlaying at least a portion of the substrate, and a second layer overlaying at least a portion of the first layer. The first layer has at least one first pore and the second layer has at least one second pore. At least a portion of the first and/or second layers are movable with respect to each other between an open condition and a closed condition in response to a change in an environmental factor. In the open condition, the first and second pores are substantially aligned to allow fluid communication between the substrate and the outside environment. In the closed condition, the first and second pores are substantially misaligned to prevent fluid communication between the substrate and the outside environment.
