4D Printing of Freestanding Liquid Crystal Elastomers via Hybrid Additive Manufacturing
4D Printing of Freestanding Liquid Crystal Elastomers via Hybrid Additive Manufacturing
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DOI：
10.1002/adma.202204890
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发表时间：
2022-08-29
影响因子：
29.4
通讯作者：
Qi, H. Jerry
中科院分区：
文献类型：
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作者：
Peng, Xirui;Wu, Shuai;Qi, H. Jerry
液晶弹性体（LCE）是4D打印活性材料中有吸引力的候选材料，因为它们具有可逆，可编程和快速驱动能力。最近已经在直接墨水书写（DIW）或数字光处理（DLP）上取得了进展，以利用某些致动来打印LCE。然而，由于在构建平台或前一层上打印LCE的限制，实现复杂结构（例如具有大致动的空间晶格）仍然是一个挑战。在本文中，提出了一种通过使用具有高达〜 40%的致动应变的激光辅助DIW来在飞行中4D打印独立LCE的新方法。该工艺进一步与DLP方法混合，用于可选的结构或可移动支撑，以在一步添加工艺中创建主动3D架构。各种物体，包括混合主动晶格，主动张拉整体，具有可调稳定性的致动器和3D空间LCE晶格，可以增材制造。因此，DIW印刷的功能独立式LCE与DLP印刷的支撑结构的组合为包括软机器人、智能结构、有源超材料和智能可穿戴设备在内的应用提供了新的设计自由度和制造能力。
Liquid crystal elastomers (LCE) are appealing candidates among active materials for 4D printing, due to their reversible, programmable and rapid actuation capabilities. Recent progress has been made on direct ink writing (DIW) or Digital Light Processing (DLP) to print LCEs with certain actuation. However, it remains a challenge to achieve complicated structures, such as spatial lattices with large actuation, due to the limitation of printing LCEs on the build platform or the previous layer. Herein, a novel method to 4D print freestanding LCEs on-the-fly by using laser-assisted DIW with an actuation strain up to -40% is proposed. This process is further hybridized with the DLP method for optional structural or removable supports to create active 3D architectures in a one-step additive process. Various objects, including hybrid active lattices, active tensegrity, an actuator with tunable stability, and 3D spatial LCE lattices, can be additively fabricated. The combination of DIW-printed functionally freestanding LCEs with the DLP-printed supporting structures thus provides new design freedom and fabrication capability for applications including soft robotics, smart structures, active metamaterials, and smart wearable devices.