4D printing shape memory polymers for dynamic jewellery and fashionwear

4D printing is a novel approach that enables dynamic functionality in ordinary static object. We used a methacrylated semicrystalline polymer to print objects exhibiting thermally triggered shape memory behaviour. By exploring various molecular weights, it was found that a methacrylated polycaprolactone polymer with a number average molecular weight of 10,000 g mol−1 exhibited the best thermal and mechanical behaviour. The effect of dyes’ addition to the ink formulation on the photopolymerisation and on the printing processes was evaluated. The ink was utilised for demonstrating fabrication of dynamic jewellery and a shoe accessory by Digital Light Processing printing.4D打印（4D printing）是一种可赋予普通静态物体动态功能的新兴技术路径。本研究采用甲基丙烯酸酯化半结晶聚合物进行打印，所得打印件可表现出热触发形状记忆行为。通过探究不同分子量的聚合物材料，研究发现数均分子量为10000 g·mol⁻¹的甲基丙烯酸酯化聚己内酯聚合物展现出最优的热学与力学性能。本研究同时评估了在打印墨水配方中添加染料对光聚合过程及打印工艺的影响。借助数字光处理（Digital Light Processing, DLP）技术，研究团队利用该墨水成功制备了动态首饰与鞋饰样品。