Dynamic solar shadings: Redefining the building envelope

Dynamic shading devices, which can respond instantaneously to varying atmospheric conditions, can minimize active energy requirements for both thermal and visual comfort. Movements in dynamic shading devices can be realized either by electrical motors/actuators or smart materials using their self-responsive properties. Actively controlled shading devices are employed in various buildings in different parts of the world, and smart material-based systems are emerging as a passive alternative. We reviewed a few selected applications of active shading devices, highlighting their technologies, user experiences, and limitations, and discussed a few potential strategies and innovations for widespread adoption by overcoming current limitations. A larger number of innovative prototypes of smart material-based shading systems have been built. The employed smart materials include: Electroactive Polymers (EP), Shape Memory Alloys (SMA), Shape Memory Polymers (SMP), and bimetals. We selected a few prototypes from each of these smart materials, presented their working mechanism, and discussed the obstacles to successful commercialization.