Key Laboratory of Chemical Biology (Ministry of Education), Beijing Key Laboratory of Microanalytical Methods & Instrumentation, Department of Chemistry, Tsinghua University, Beijing, 100084, China.
Adv Mater. 2017 Sep;29(34). doi: 10.1002/adma.201701664. Epub 2017 Jun 22.
Materials with microchannels have attracted increasing attention due to their promising perfusability and biomimetic geometry. However, the fabrication of microfibers with more geometrically complex channels in the micro- or nanoscale remains a big challenge. Here, a novel method for generating scalable microfibers with consecutive embedded helical channels is presented using an easily made coaxial microfluidic device. The characteristics of the helical channel can be accurately controlled by simply adjusting the flow rate ratio of the fluids. The mechanism of the helix formation process is theorized with newly proposed heterogenerated rope-coil effect, which enhances the tunability of helical patterns and promotes the comprehension of this abnormal phenomenon. Based on this effect, microfibers with embedded Janus channels and even double helical channels are generated in situ by changing the design of the device. The uniqueness and potential applications of these tubular microfibers are also demonstrated by biomimetic supercoiling structures as well as the perfusable and permeable spiral vessel.
由于其良好的灌注性能和仿生几何形状，具有微通道的材料引起了越来越多的关注。然而，在微纳尺度上制造具有更复杂几何形状通道的微纤维仍然是一个巨大的挑战。在这里，提出了一种使用易于制造的同轴微流控装置生成具有连续嵌入式螺旋通道的可扩展微纤维的新方法。通过简单地调整流体的流速比，可以精确控制螺旋通道的特性。通过新提出的异质绳-线圈效应来理论化螺旋形成过程的机制，该效应增强了螺旋图案的可调性，并促进了对这种异常现象的理解。基于该效应，通过改变装置的设计，可在原位生成具有嵌入式 Janus 通道甚至双螺旋通道的微纤维。仿生超螺旋结构以及可灌注和可渗透的螺旋血管也证明了这些管状微纤维的独特性和潜在应用。
