Direct Fused Deposition Modeling 4D Printing and Programming of Thermoresponsive Shape Memory Polymers with Autonomous 2D‐to‐3D Shape Transformations

• Published in: Advanced engineering materials Vol. 25; no. 19
• Main Authors: Hu, Guofeng, Bodaghi, Mahdi
• Format: Journal Article
• Language: English
• Published: 01.10.2023
• Subjects: 4D printing; direct programming; fused deposition modeling; shape memory polymers; shape transformations
• ISSN: 1438-1656; 1527-2648
• DOI: 10.1002/adem.202300334

Herein, direct 4D printing of thermoresponsive shape memory polymers (SMPs) by the fused deposition modeling (FDM) method that enables programing of 2D objects during printing for autonomous 2D‐to‐3D shape transformations via simply heating is focused on. The programming process during printing is investigated through designs and experiments. The capability of programming SMPs during printing is illustrated by prestrain and bending capabilities, which are highly related to printing settings, such as nozzle temperature, print speed, layer height, infill patterns, and ratio of active parts in a bilayer structure. A nearly linear relationship for prestrain and bending parameters is experimentally revealed for different printing factors. Quantitative results are presented to be used as a guidance for designing complex 3D structures via 4D printing of 2D structures. Helix structure, twisting structure, DNA‐like structures, and functional gripper are designed to demonstrate the potential of direct FDM 4D printing for creating complex 3D structures from simple 2D structures with advantages over traditional manufacturing methods. It is shown that, by removing the need for a layer‐by‐layer stacking process to achieve a complex 3D shape, FDM can promote sustainability via 4D printing of autonomous 2D‐to‐3D shape transformer structures with lower materials, time, energy, and longer service life. A novel direct fused deposition modeling (FDM) 4D printing method enables creating complex 3D shape structures from simple 2D flat structures with higher mechanical strength, higher energy efficiency, and better sustainability. FDM 4D printing performs thermomechanical programming, simultaneously leading to a shape change directly right after printing with certain stimuli.