Micro/nanofabrication of brittle hydrogels using 3D printed soft ultrafine fiber molds for damage-free demolding
Micro/nanofabrication of brittle hydrogels using 3D printed soft ultrafine fiber molds for damage-free demolding
复制标题
使用 3D 打印的软超细纤维模具对脆性水凝胶进行微/纳米加工，以实现无损伤脱模
DOI：
10.1088/1758-5090/ab57d8
复制
发表时间：
2020-04-01
期刊：
影响因子：
9
通讯作者：
He, Yong
中科院分区：
文献类型：
--
作者：
Lv, Shang;Nie, Jing;He, Yong
水凝胶因其优异的生物相容性而在生物医学领域受到广泛关注。然而，大多数生物水凝胶太脆而不能进行微/纳米制造。一种有效的方法是浇铸成型，但在此过程中，由于过度的脱模应力破坏了脆性水凝胶，因此会出现许多缺陷。在此，我们提出一种全新的无损伤脱模方法和一种柔软的超细纤维模具（SUFM）来取代传统的模具。力学和有限元分析（FEA）表明，SUFM具有明显的优势，特别是当水凝胶和模具之间的接触面积变大。通过称为电流体动力学（EHD）打印的高分辨率3D打印，可以以低成本实现具有各种拓扑结构的SUFM，纤维直径范围从500 nm到100 μ m。微流体和细胞模式的实施作为潜在应用的示范。由于微结构的微小尺度和水凝胶的亲水性，产生显著的毛细效应，可以利用该毛细效应自主地递送液体和细胞，并将细胞均匀地接种到那些超细通道中。这些结果为水凝胶在生物医学设备、组织工程、基于水凝胶的微流体和可穿戴电子设备中的更广泛应用开辟了新的途径;所提出的制造方法也有可能成为脆性材料微/纳米制造的通用技术。
Hydrogels are very popular in biomedical areas for their extraordinary biocompatibility. However, most bio-hydrogels are too brittle to perform micro/nanofabrication. An effective method is cast molding; yet during this process, many defects occur as the excessive demolding stress damages the brittle hydrogels. Here, we propose a brand-new damage-free demolding method and a soft ultrafine fiber mold (SUFM) to replace the traditional mold. Both mechanical and finite element analysis (FEA) reveal that SUFMs have obvious advantages especially when the contact area between hydrogel and mold gets larger. By means of a high-resolution 3D printing called electrohydrodynamic (EHD) printing, SUFMs with various topological structures can be achieved with the fiber diameter ranging from 500 nm to 100 mu m, at a low cost. Microfluidics and cell patterns are implemented as the demonstration for potential applications. Owing to the tiny scale of microstructures and the hydrophilicity of hydrogels, significant capillary effect occurs which can be utilized to deliver liquid and cells autonomously and to seed cells into those ultrafine channels evenly. The results open up a new avenue for a wider use of hydrogels in biomedical devices, tissue engineering, hydrogel-based microfluidics and wearable electronics; the proposed fabrication method also has the potential to become a universal technique for micro/nanofabrication of brittle materials.