Prototyping of 4D-printed self-shaping building skin in architecture: Design, fabrication, and investigation of a two-way shape memory composite (TWSMC) façade panel

The article seeks to demonstrate the potential architectural utility of reversible 4D-printed material for flexible climate adaptation of building. This work presents the engineered design, fabrication, and performative effectiveness of a responsive façade morphing with the use of thermo-responsive shape-memory composites (SMCs). Load-free bidirectional motion of an SMC is configured by combining programmed shape-memory alloy (SMA) fibers and 3D-printed shape-memory polymer (SMP) matrix. Different thermomechanical properties were tested and applied to make building shape change possible according to the variation of outside temperature. For design experiments, the SMC models were fabricated and deployed over the exterior surface of a test building scale model. To help architectural communities better understand responsive material phenomena for building design application, the self-shaping material performance was modeled and evaluated through digital simulation, using theoretical constitutive equations and physical observation of the test building model. The findings reveal merits and opportunities of the smart material use and 4D-printed adaptive architecture, as well as several limitations in current technology and material development for building applications.