This paper investigates the entire process of 4D printing of shape memory alloys (SMAs), characterized by pre-programming of the future responsive shape of a deformable structure during its 3D forming. Taking an inchworm-inspired crawling robot as an application case, we propose a system prototype composed of two deformable SMA structures, i.e. a curved sheet and a spring coil. From the behavioral synergism of these two antagonistically configured structures, the initial and responsive shapes of each binary structure were collaboratively designed. The feature shapes of different structures were then pairwise combined to generate the robot’s gait, which was realized through the alternating activations of the two components. We also investigated the processing strategy and methods of the presented structures with small feature sizes and unique configurations, based on the optimal 3D printing process of selective laser melting of nickel–titanium alloys. The experimental results verified the design expectations and demonstrated the performance stability of the SMA structures under multiple testing cycles. This research confirmed the possible use of hard materials to create customized smart structures with high levels of flexibility and deformation control, providing new ideas for further development of intelligent, flexible robots.

本文研究了形状记忆合金（SMA）的4D打印的整个过程，其特征是对可变形结构的3D成型过程中未来响应形状的预编程。以受蠕虫感染的爬行机器人为应用案例，我们提出了一个系统原型，该系统原型由两个可变形的SMA结构组成，即弯曲板和弹簧线圈。从这两个对立配置的结构的行为协同作用，共同设计了每个二元结构的初始形状和响应形状。然后将不同结构的特征形状成对组合以生成机器人的步态，这是通过两个组件的交替激活来实现的。我们还基于镍钛合金选择性激光熔融的最佳3D打印工艺，研究了具有小特征尺寸和独特配置的结构的加工策略和方法。实验结果验证了设计预期，并证明了SMA结构在多个测试周期下的性能稳定性。这项研究证实了可能使用硬质材料来创建具有高度灵活性和变形控制能力的定制智能结构，为进一步开发智能，灵活的机器人提供了新思路。实验结果验证了设计预期，并证明了SMA结构在多个测试周期下的性能稳定性。这项研究证实了可能使用硬质材料来创建具有高度灵活性和变形控制能力的定制智能结构，为进一步开发智能，灵活的机器人提供了新思路。实验结果验证了设计预期，并证明了SMA结构在多个测试周期下的性能稳定性。这项研究证实了可能使用硬质材料来创建具有高度灵活性和变形控制能力的定制智能结构，为进一步开发智能，灵活的机器人提供了新思路。