电纺直写纳米纤维在图案化基底的定位沉积

为进一步提高单根电纺丝纳米纤维的定位沉积和形貌控制水平,基于近场静电纺丝技术,研究了单根直写纳米纤维在无图案硅基底的沉积行为;仿真分析了图案化硅基底上方的空间电场分布;采用图案化硅基底作为收集板,实验考察了微图案形状、收集运动速度等因素对单根纳米纤维定位沉积的影响规律。实验结果显示,电纺直写技术具有良好的定位精度,可将直径为100～800 nm的纳米纤维精确定位于直径仅为1.6μm的圆形微图案阵列上表面;收集板运动速度较小时,受电场力影响纳米纤维沉积轨迹将朝微图案偏移7μm;收集板运动速度进一步减小时,纳米纤维在基底微图案附近或上表面产生聚集;长条形微图案对纳米纤维沉积过程具有良好的引导与约束作用。得到的结果表明,基于近场静电纺丝的直写技术可较好地实现单根纳米纤维在图案化硅基底的精确定位沉积。

Position deposition of electrospinning direct-writing nanofiber on pattern substrate

In order to improve the position deposition and morphology controlling of a single electrospun nanofiber in industrial applications,an electrospinning Direct-writing (DW) technology was studied further. Firstly, the DW technology based on the Near-Field Electrospinning (NFES) was utilized to investigate the deposition behavior of a single DW nanofiber on the flat silicon substrate. Then, the electrical field distribution above the patterned silicon substrate was simulated. Finally, patterned silicon substrate was used as a collector, and the effect of pattern structure and the motion speed of the collector on the position deposition of single DW nanofiber was analyzed.Experimental results demonstrate that the DW nanofiber with the diameter ranges from 100 nm to 800 nm can be deposited precisely on the top surface of a circle micro-pattern array with a diameter of 1.6 μm. When motion speed of the collector is lower than the electrospinning speed, the deposition location of DW nanofiber would deviate from the motion track and move from the pattern in 7 μm due to the electric field force. If the motion speed of the collector decreases further, more nanofiber would congregate around the micro pattern or on the top surface of pattern. The strip pattern plays an excellent guiding and restricting role on the deposition of single DW nanofiber. It is concluded that the DW technology based on NFES can provide a simple way for the precise position of single nanofibers on patterned silicon substrates.