4D Printing of Surface Morphing Hydrogels
4D Printing of Surface Morphing Hydrogels
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DOI：
10.1002/admt.202101118
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发表时间：
2021-12
影响因子：
6.8
通讯作者：
Chya‐Yan Liaw;J. Pereyra;A. Abaci;Shen Ji;M. Guvendiren
中科院分区：
文献类型：
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作者：
Chya‐Yan Liaw;J. Pereyra;A. Abaci;Shen Ji;M. Guvendiren
聚合物系统显示自发形成的表面起皱图案是有用的广泛的应用，如衍射光栅，柔性电子，智能粘合剂，光学器件和细胞培养平台。传统的皱纹图案制造技术涉及大量的加工步骤，并对分层图案的制造、在三维和非平面结构上产生皱纹、制造过程的可扩展性以及将皱纹制造过程集成到连续制造过程中施加了重大限制。在这项工作中，报告了表面变形水凝胶的4D打印，可以直接在弯曲和/或3D结构上制造褶皱图案，并具有用户定义和空间控制的图案几何形状和尺寸。成功印刷的关键是调整水凝胶油墨的光聚合时间和部分交联时间。交联剂浓度和印后交联时间之间的相互作用可以控制褶皱形态和图案的特征尺寸。图案对齐是由打印支柱尺寸控制的，打印支柱尺寸是打印喷嘴以直线形式挤出的固体材料的尺寸。为了证明该方法的实用性，制造了可调谐光学器件、用于微芯片的溶剂/湿度传感器和用于控制干细胞形状的细胞培养平台。
Polymeric systems displaying spontaneous formation of surface wrinkling patterns are useful for a wide range of applications, such as diffraction gratings, flexible electronics, smart adhesives, optical devices, and cell culture platforms. Conventional fabrication techniques for wrinkling patterns involves multitude of processing steps and impose significant limitations on fabrication of hierarchical patterns, creating wrinkles on 3D and nonplanar structures, the scalability of the manufacturing process, and the integration of wrinkle fabrication process into a continuous manufacturing process. In this work, 4D printing of surface morphing hydrogels enabling direct fabrication of wrinkling patterns on curved and/or 3D structures with user‐defined and spatially controlled pattern geometry and size is reported. The key to successful printing is to tailor the photopolymerization time and partial crosslinking time of the hydrogel inks. The interplay between crosslinker concentration and postprinting crosslinking time allow for the control over wrinkling morphology and the characteristic size of the patterns. The pattern alignment is controlled by the print strut size—the size of the solid material extruded from the print nozzle in the form of a line. To demonstrate the utility of the approach, tunable optical devices, a solvent/humidity sensor for microchips, and cell culture platforms to control stem cell shape are fabricated.