Wire-in-a-nozzle as a new droplet-on-demand electrogenerator.
Wire-in-a-nozzle as a new droplet-on-demand electrogenerator.
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DOI：
10.1021/la104855b
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发表时间：
2011-02
期刊：
影响因子：
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通讯作者：
Taras Andrukh;B. Rubin;K. Kornev
中科院分区：
文献类型：
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作者：
Taras Andrukh;B. Rubin;K. Kornev
许多工程应用假定按需产生单个球形液滴。压电液滴和按需热液滴(DOD)仪器不能从同一喷嘴产生大范围尺寸分布的液滴。我们证明，这一挑战可以使用静电产生和毛细作用的原理来解决。一根穿过针头的细导线可以用作液滴发电机(或DOD发电机)。通过施加弱偏置电场，人们可以将一滴液滴从针的边缘输送到自由线的尖端。当液滴向线头移动时，会留下一层薄薄的涂层。这种圆柱形薄膜的毛细压力有助于将液滴与液源隔离：薄膜会自发变薄，断开液滴和液源之间的连接。然后，通过施加短电压脉冲来实现悬挂滴从导线上的脱离。使用针线喷嘴，我们能够产生从50到500μm的单个液滴，并能够将它们以可控的速度沉积在指定的位置。因此，提出的方法为处理国防部应用领域提供了新的机会。
Many engineering applications assume the generation of single spherical droplets on demand. Piezo and thermo droplet-on-demand (DOD) instruments are not able to produce droplets with a broad range of size distributions from the same nozzle. We show that this challenge can be resolved using the principles of electrostatic generation and capillarity. A thin conductive wire threaded through a needle can be used as the droplet electrogenerator (or DOD generator). By applying a weak-bias electric field, one can deliver a drop from the needle edge to the free wire tip. When the drop moves toward the wire tip, it leaves behind a thin coating film. The capillary pressure of this cylindrical film helps isolate the droplet from the liquid source: the film spontaneously thins, breaking the connection between the droplet and the liquid source. The detachment of a pendant drop from the wire is then achieved by applying a short voltage pulse. Using the wire-in-a-needle nozzle, we were able to produce single droplets ranging from 50 to 500 μm, and we were able to deposit them with controlled velocity in a prescribed position. Therefore, the proposed method offers new opportunities in fields dealing with the DOD applications.