Additive manufacturing (AM), commonly known as 3D printing, has revolutionized the way complex geometries are designed and fabricated. Building upon this foundation, the emergence of 4D printing—the integration of time as a functional dimension—enables printed structures to change shape or function in response to external stimuli such as heat, moisture, or light. This dynamic behavior has opened new avenues in fields ranging from biomedical devices to aerospace systems. This paper explores the development and implementation of 4D printing techniques using acrylonitrile butadiene styrene (ABS) to fabricate complex, stimuli-responsive structures. By leveraging the intrinsic thermomechanical properties of ABS and carefully programming the printing path, we demonstrate the ability to induce time-dependent shape transformations in static 3D-printed geometries. The study presents a detailed analysis of design strategies, process parameters, and post-processing techniques that enable controlled deformation in response to thermal stimuli. Several prototypes with intricate geometries are fabricated and tested, showcasing reversible and irreversible transformations. The results highlight the feasibility of using conventional FDM-based 3D printers and ABS filaments for creating cost-effective, functional 4D-printed components, opening new possibilities for applications in soft robotics, deployable systems, and adaptive structures.
Kostopoulos et al. (Mon,) studied this question.