Physical Chemistry 1, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
Lab Chip. 2014 May 21;14(10):1733-45. doi: 10.1039/c3lc51363g. Epub 2014 Mar 27.
We present microfluidic chip based devices that produce liquid jets with micrometer diameters while operating at very low flow rates. The chip production is based on established soft-lithographical techniques employing a three-layer design protocol. This allows the exact, controlled and reproducible design of critical parts such as nozzles and the production of nozzle arrays. The microfluidic chips reproducibly generate liquid jets exiting at perfect right angles with diameters between 20 μm and 2 μm, and under special circumstances, even down to 0.9 μm. Jet diameter, jet length, and the domain of the jetting/dripping instability can be predicted and controlled based on the theory for liquid jets in the plate-orifice configuration described by Gañán-Calvo et al. Additionally, conditions under which the device produces highly reproducible monodisperse droplets at exact and predictable rates can be achieved. The devices operate under atmospheric and under vacuum conditions making them highly relevant for a wide range of applications, for example, for free-electron lasers. Further, the straightforward integration of additional features such as a jet-in-jet is demonstrated. This device design has the potential to integrate more features based on established microfluidic components and may become a standard device for small liquid jet production.
我们提出了一种基于微流控芯片的装置，该装置能够以非常低的流速产生直径为微米级的液滴。该芯片的制作基于成熟的软光刻技术，采用三层设计方案。这种设计方案能够精确、可控且可重复地设计关键部件，如喷嘴，并制作喷嘴阵列。微流控芯片能够稳定地产生直径在 20μm 到 2μm 之间的液滴，在特殊情况下甚至可以达到 0.9μm。基于 Gañán-Calvo 等人描述的平板-孔口结构中液体射流的理论，可以预测和控制射流直径、射流长度以及射流/滴落不稳定性的范围。此外，还可以实现以精确且可预测的速率产生高度重现性单分散液滴的条件。该装置在大气和真空条件下运行，因此非常适用于各种应用，例如自由电子激光器。此外，还展示了一种基于微流控组件的集成式射流内射流装置。这种装置设计有潜力基于成熟的微流控组件集成更多功能，并可能成为小型液体射流产生的标准装置。
