Modak Chandantaru Dey, Kumar Arvind, Tripathy Abinash, Sen Prosenjit
Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore, Karnataka, 560012, India.
Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia.
Nat Commun. 2020 Aug 28;11(1):4327. doi: 10.1038/s41467-020-18103-6.
Hydrodynamic collapse of a central air-cavity during the recoil phase of droplet impact on a superhydrophobic sieve leads to satellite-free generation of a single droplet through the sieve. Two modes of cavity formation and droplet ejection have been observed and explained. The volume of the generated droplet scales with the pore size. Based on this phenomenon, we propose a drop-on-demand printing technique. Despite significant advancements in inkjet technology, enhancement in mass-loading and particle-size have been limited due to clogging of the printhead nozzle. By replacing the nozzle with a sieve, we demonstrate printing of nanoparticle suspension with 71% mass-loading. Comparatively large particles of 20 μm diameter are dispensed in droplets of ~80 μm diameter. Printing is performed for surface tension as low as 32 mNm and viscosity as high as 33 mPa∙s. In comparison to existing techniques, this way of printing is widely accessible as it is significantly simple and economical.
在液滴冲击超疏水筛网的反冲阶段，中央气腔的流体动力学坍塌导致单个液滴通过筛网无卫星液滴地生成。已观察并解释了两种气腔形成和液滴喷射模式。生成液滴的体积与孔径成比例。基于这一现象，我们提出了一种按需滴印技术。尽管喷墨技术取得了重大进展，但由于打印头喷嘴堵塞，质量负载和颗粒尺寸的提高受到限制。通过用筛网代替喷嘴，我们展示了质量负载为71%的纳米颗粒悬浮液的打印。直径为20μm的相对较大颗粒被分配到直径约80μm的液滴中。对于低至32mN/m的表面张力和高达33mPa·s的粘度进行打印。与现有技术相比，这种打印方式因其显著简单且经济而广泛适用。
