Li Jingmei, Kong Tiantian, Yu Jiazuo, Lee Kit Hang, Tang Yuk Heng, Kwok Ka-Wai, Kim Ji Tae, Shum Ho Cheung
Department of Mechanical Engineering, University of Hong Kong, Pokfulam Road, 999077, Hong Kong.
China Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, Shenzhen University, 518037, China.
Lab Chip. 2019 Jun 7;19(11):1953-1960. doi: 10.1039/c9lc00145j. Epub 2019 May 2.
The rope coiling observed in liquid ink with high viscosity has been exploited in additive printing to fabricate architectures with periodically curled structures and tune their mechanical properties. However, the control over the coiling path relying on mechanical motion restricts the spatiotemporal resolution. We develop an electrically assisted high-resolution technique to manipulate coiling paths of viscous ink and structures of the deposited filament. By spatially programming the voltage applied onto the viscous ink, we show that the switching between different filament structures can be accomplished at single wavelength resolution, facilitating the rapid and accurate construction of sophisticated patterns. Furthermore, translational guiding of the electrocoiling enables rapid printing of filaments with complex structures at a line speed of 10 mm s. With a simplified trajectory of the printing head, large-area and multiscale patterns can be printed at an unprecedented speed; for instance, centimeter-sized architectures constructed from nanofibers with micron-sized curled structures can be completed in a few minutes. By enabling the printing of complex fiber networks with tunable shape and density, our work provides a route towards custom-design of fiber architectures with unique features such as spatially varying mechanical properties.
在高粘度液体油墨中观察到的绳索盘绕现象已被用于增材打印，以制造具有周期性卷曲结构的架构并调整其机械性能。然而，依靠机械运动对盘绕路径的控制限制了时空分辨率。我们开发了一种电辅助高分辨率技术，以操纵粘性油墨的盘绕路径和沉积细丝的结构。通过对施加在粘性油墨上的电压进行空间编程，我们表明可以在单波长分辨率下实现不同细丝结构之间的切换，这有助于快速准确地构建复杂图案。此外，电盘绕的平移引导能够以10毫米/秒的线速度快速打印具有复杂结构的细丝。通过简化打印头的轨迹，可以以前所未有的速度打印大面积和多尺度图案；例如，由具有微米级卷曲结构的纳米纤维构建的厘米级架构可以在几分钟内完成。通过能够打印具有可调形状和密度的复杂纤维网络，我们的工作为定制设计具有独特特征（如空间变化的机械性能）的纤维架构提供了一条途径。
