Shape-Morphing Polymers – Fabrication through Blending and 3D Printing

The ability to program a stimuli-responsive shape-change into a material is of significant interest for remotely deployable devices and sensors across a range of industries, such as aerospace, packaging, and medicine. Polymers are the ideal platform for designing shape-morphing materials due to their inherent elasticity and extensibility. This talk will discuss the fabrication of shape-morphing polymer by combining elastomers and molecular crystals. This decoupling of the material components provides wide latitude in material selection. Two main types of systems will be discussed. The first is shape memory polymers where crystals are used to immobilize stretched chains imparts a stimuli-responsive shape memory effect. The second are reversible actuators where the dilation/contraction of the molecular additive through a phase transition drives reversible deformation of the surrounding elastomer. In layered systems this can produce large-range motion through bending and twisting. Efforts to 3D print shape-morphing polymer articles will be discussed using extrusion based printers. In addition to net-shape manufacturing, the external fields applied to the polymer through shear and extensional impart orientation, resulting in anisotropic properties that are used to directly program the macroscopic shape morphing behavior.