Abstract Conventional methods of programmed shape change in polymers are one-way and one-time only. We introduce a new method of combining a bioinspired, hierarchical architecture with the pre-strain generated by extrusion-based 3D printing to encode multiple permanent shapes in thermoplastic polymer shell structures. At high temperature, these structures are multistable and can snap repeatedly between all encoded permanent shapes without reprogramming. At low temperature, the structures are monostable with increased stiffness; the multistability can be switched on and off via temperature. Characterization studies are performed to determine how to control the level of pre-strain and the deflection behavior of the structure to enable finite element modeling for analysis and design. This pre-straining technique may be thought of as a virtual mold: printed structures are initially flat but have multiple permanent shapes encoded. Taking advantage of the geometric freedom of 3D printing, complex geometries, and pre-strain fields may be used to create highly tailored snapping structures. Thermoplastic filaments with added particles may be used to impart additional multifunctionality to the structures, such as magnetic responsiveness, to enable remote actuation. These switchable multistable structures have potential applications in fields including robotics, aerospace, and smart buildings.

中文翻译：

---

在 3D 打印结构中编码多个永久形状

摘要 聚合物程序化形状变化的常规方法是单向和一次性的。我们引入了一种新方法，将仿生的分层结构与基于挤出的 3D 打印产生的预应变相结合，以在热塑性聚合物壳结构中编码多个永久形状。在高温下，这些结构是多稳态的，并且可以在所有编码的永久形状之间重复咬合，而无需重新编程。在低温下，结构是单稳态的，刚度增加；多重稳定性可以通过温度打开和关闭。进行表征研究以确定如何控制预应变水平和结构的偏转行为，以实现用于分析和设计的有限元建模。这种预应变技术可以被认为是一个虚拟的模具：印刷结构最初是平坦的，但有多个永久形状编码。利用 3D 打印的几何自由度，复杂的几何形状和预应变场可用于创建高度定制的捕捉结构。添加了颗粒的热塑性长丝可用于赋予结构额外的多功能性，例如磁响应性，以实现远程驱动。这些可切换的多稳态结构在机器人、航空航天和智能建筑等领域具有潜在应用。添加了颗粒的热塑性长丝可用于赋予结构额外的多功能性，例如磁响应性，以实现远程驱动。这些可切换的多稳态结构在机器人、航空航天和智能建筑等领域具有潜在应用。添加了颗粒的热塑性长丝可用于赋予结构额外的多功能性，例如磁响应性，以实现远程驱动。这些可切换的多稳态结构在机器人、航空航天和智能建筑等领域具有潜在应用。