Multi-material 4D printing to realize two-phase morphing in self-actuating structures

4D printing has garnered significant attention within the field of engineering due to its capacity to introduce novel functionalities in printed structures through shape-morphing. Nevertheless, there persist challenges in the design and fabrication of intricate structures, primarily stemming from the intricate task of controlling variables that impact morphing characteristics. In order to surmount these hurdles, the approach of multi-material 4D printing is employed, underpinned by parametric studies, to actualize complex structures through a two-phase morphing process. This study specifically investigates the utilization of acrylonitrile butadiene styrene (ABS) and polycarbonate/ABS. The distinction in glass transition temperatures within these materials enables the realization of two distinct morphing phases. The research delves into the impact of structural parameters on morphing properties. Finite element analyses are subsequently conducted, leveraging the insights gained from parametric studies, to facilitate the accurate prediction of a diverse array of shape alterations in response to temperature fluctuations. Several structural models are both simulated and fabricated to experimentally validate the precise forecasting of desired morphing phases. The culmination of this study manifests in the design and fabrication of multiple multi-material structures, exemplifying both their functionality and intricate geometric complexity.