4D Printing Via Multispeed Fused Deposition Modeling

4D printing is an advanced technology that aims to endow the additively manufactured objects with time-dependent transformations. Despite the great progress in the last decade, however, there are still some technical barriers for the majority of existing 4D printing techniques including the dependency on customized or expensive 3D printers and the demand of sophisticated chemistry in the preparation of active materials. Herein, an efficient and economical 4D printing approach that adopts multispeed fused deposition modeling (FDM) technique to embed graded built-in strain into flat precursory pattern is proposed, allowing for prompt and talorable shapeshifting upon heat stimulus. Guided by the systematic optimization of FDM processing parameters, it is allowed to directly construct complex 3D structures from flat precursory patterns with flexibility and high fidelity, considerably reducing the built time and process complexity.