Rapid and selective actuation of 3D-printed shape-memory composites via microwave heating

Abstract

Three-dimensional (3D) printing allows the fabrication of complex shapes with high resolutions. However, the printed structures typically have fixed shapes and functions. Four-dimensional printing allows the shapes of 3D-printed structures to be transformed in response to external stimuli. Among the external stimuli, light has unique advantages for remote thermal actuation. However, light absorption in opaque structures occurs only near the sample surface; thus, actuation can be slow. Here, we propose and experimentally demonstrate the rapid and selective actuation of 3D-printed shape-memory polymer (SMP) composites using microwave heating. The SMP composite filaments are prepared using different amounts of graphite flakes. Microwave radiation can penetrate the entire printed structures and induce rapid heating. With sufficient graphite contents, the printed SMP composites are heated above their glass transition temperature within a few seconds. This leads to rapid thermal actuation of the 3D-printed SMP structures. Finally, dual-material 3D printing is demonstrated to induce selective microwave heating and control actuation motion. Our experiments and simulations indicate that microwave heating of SMP composites can be an effective method for the rapid and selective actuation of complex structures.

Fibrous Structures: An Overview of Their Responsiveness to External Stimuli towards Intended Application

“…Among these, the most common SMPs is the dual SMPs [70]. SMPs have potential applications in smart textiles [64], biomedicine [71], self-healing composite systems [72], civil engineering [73], 3D printing [74] and other fields.…”

Self-Healing Polymers Coupling Shape Memory Effect

“…External stimuli such as heat, light, and electromagnetism have been widely employed to expedite the self-healing process between interfaces. Excitingly, these varied external stimuli also serve as ideal means to control the shape programming-recovery process of SMPs. − Here, we primarily delineate several commonly used diverse driving methods of SMPs, and we explore the effects of different driving methods on self-healing behavior.…”