Design, prototyping, and evaluation of a concept for a shape-changing smart material building surface tile

Abstract

Abstract A design concept for shape-changing smart material tiles for applications in environmentally responsive building facades is presented. In particular, the application considered is a tile that would change the shape of the building surface to favorably affect the interaction with solar irradiance. A lab-scale prototype system for smart material tiles composed of 3D printed thermally responsive shape memory polymer (SMP) and utilizing localized thermal material activation and uniform pressure actuation is examined. Tests utilizing the prototype tile are used to create and validate a computational (finite element) representation of the adaptive surface tile system. Toward developing this computational representation, a strategy is presented to determine and validate the material parameters for the 3D printed SMP by matching the tile shape predicted by the numerical model to the tile shape measured experimentally. This numerical representation was then implemented into a computational approach to explore the design space for this adaptive tile to have an effect on the solar irradiance on a building surface. More specifically, a series of numerical examples are considered that determine the location and size of material activation that minimize the area of the tile exposed to solar irradiance. Results indicate that the adaptive tile can change the surface of a structure to considerably improve the structure’s interaction with solar irradiance. Additionally, the importance of the control strategy for a multi-tile system was displayed, particularly with respect to the capability to significantly reduce the energy cost and affect the solar irradiance to a higher degree by accounting for neighboring tile interaction.