We present a microfluidic nozzle device for the controlled continuous solution blow spinning of ultrafine fibers. The device is fabricated by soft lithography techniques and is based on the principle of a gas dynamic virtual nozzle for precise three-dimensional gas focusing of the spinning solution. Uniform fibers with virtually endless length can be produced in a continuous process while having accurate control over the fiber diameter. The nozzle device is used to produce ultrafine fibers of perfluorinated copolymers and of polycaprolactone, which are collected and drawn on a rotating cylinder. Hydrodynamics and mass balance quantitatively predict the fiber diameter, which is only a function of flow rate and air pressure, with a small correction accounting for viscous dissipation during jet formation, which slightly reduces the jet velocity. Because of the simplicity of the setup, the precise control of the fiber diameter, the positional stability of the exiting ultrafine fiber and the potential to implement arrays of parallel channels for high throughput, this methodology offers significant benefits compared to existing solution-based fiber production methods.

中文翻译：

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用于精确控制直径的超细纤维溶液吹纺的微流体喷嘴装置†

我们提出了一种用于超细纤维的受控连续溶液吹纺的微流体喷嘴装置。该设备是通过软光刻技术制造的，并且基于气体动态虚拟喷嘴的原理，可对纺丝溶液进行精确的三维气体聚焦。可以连续过程生产几乎无限长的均匀纤维，同时可以精确控制纤维直径。喷嘴装置用于生产全氟共聚物和聚己内酯的超细纤维，将其收集并拉到旋转的圆筒上。流体力学和质量平衡定量地预测了纤维直径，该直径仅是流速和气压的函数，对射流形成过程中的粘性耗散进行了较小的校正，从而稍微降低了射流速度。