4D printing of shape-changing thermo-responsive textiles

Abstract

This research reviews the state-of-the-art literature on the two-emerging material-driven Additive Manufacturing (AM) strategies, Functionally Graded Additive Manufacturing (FGAM) and 4D Printing (4DP) to recognise, select and implement the appropriate materials, design and fabrication methods to produce shape-changing thermo-responsive textiles. Shapememory polymers (SMPs) are required to provide the active properties required to sense and self-actuate when subjected to an appropriate stimulus over time. The current availability of SMPs for AM in the commercial market is limited and expensive. To ensure a wider uptake of 4DP, the aim of this research is to develop a material selection framework to discover, define and select commercially available thermoplastics as potential SMPs for use in material extrusion (ME) 4DP. The theoretical and practical knowledge to create a thermally actuated dual-state mechanism (DSM) active structure is described at a feasible level for users with different backgrounds and knowledge levels in 4DP. The experiments showed that commercial AM filaments could be used for 4DP, but not all materials exhibit shape memory properties despite belonging to the same material type. The shape recovery performance and repeatability of an SMP would also vary according to the programming condition. The next stage of this research details the development and testing of polymertextile composites using direct ME of PLA filaments on synthetic mesh fabrics. T-peel test results revealed that the compatibility between the printing material and the textile substrate fibre type has a dominant effect on the peel resistance of ME polymer-textile composite. The research demonstrated the use of 4DP as an alternative and novel technique for the 3D manipulation of textile fabrics. The shape transformation studies presented a proof-ofconcept that the accuracy of deformation and the shape-shifting patterns of the thermoresponsive textiles can be controlled by the geometrical dimensions and structural arrangement of the printed SMP structure on the textile substrate. The findings will enable researchers and designers to take advantage of the optimum parameters to discover new shape transformations and to create potential applications in the AM fashion and textile industry.