Active origami by 4D printing
Active origami by 4D printing
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DOI：
10.1088/0964-1726/23/9/094007
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发表时间：
2014-09-01
影响因子：
4.1
通讯作者：
Dunn, Martin L.
中科院分区：
文献类型：
--
作者：
Ge, Qi;Dunn, Conner K.;Dunn, Martin L.
三维（3D）打印技术的最新进展允许在每层内打印多种材料，从而可以创建具有精确控制的异质微结构的材料和组件。此外，可以打印活性材料，如形状记忆聚合物，以在固体中创建活性微观结构。这些活性材料随后可以以受控的方式被激活，以响应环境刺激而改变固体的形状或结构。这被称为4D打印，第四个维度是打印后随时间变化的形状变化。在本文中，我们将4D打印概念推进到主动折纸的设计和制造中，其中平面自动折叠成复杂的3D组件。在这里，我们用精确打印在弹性体基质上的形状记忆聚合物纤维打印活性复合材料，并将它们用作智能主动铰链，以实现折纸折叠模式。我们建立了一个理论模型，为选择设计参数提供指导，如纤维尺寸，铰链长度，编程应变和温度。利用该模型，我们设计并制造了几个由扁平聚合物片组装而成的活性折纸组件，包括一个盒子、一个金字塔和两个折纸飞机。此外，我们直接打印一个具有活动复合铰链的3D盒子，并对其进行编程，使其具有临时的平面形状，随后根据需要恢复到3D盒子形状。
Recent advances in three dimensional (3D) printing technology that allow multiple materials to be printed within each layer enable the creation of materials and components with precisely controlled heterogeneous microstructures. In addition, active materials, such as shape memory polymers, can be printed to create an active microstructure within a solid. These active materials can subsequently be activated in a controlled manner to change the shape or configuration of the solid in response to an environmental stimulus. This has been termed 4D printing, with the 4th dimension being the time-dependent shape change after the printing. In this paper, we advance the 4D printing concept to the design and fabrication of active origami, where a flat sheet automatically folds into a complicated 3D component. Here we print active composites with shape memory polymer fibers precisely printed in an elastomeric matrix and use them as intelligent active hinges to enable origami folding patterns. We develop a theoretical model to provide guidance in selecting design parameters such as fiber dimensions, hinge length, and programming strains and temperature. Using the model, we design and fabricate several active origami components that assemble from flat polymer sheets, including a box, a pyramid, and two origami airplanes. In addition, we directly print a 3D box with active composite hinges and program it to assume a temporary flat shape that subsequently recovers to the 3D box shape on demand.