Shi Dachuang, Chen Yun, Yao Yao, Hou Maoxiang, Chen Xin, Gao Jian, He Yunbo, Zhang Guoping, Wong Ching-Ping
State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, Guangdong University of Technology, Guangzhou 510006, China.
School of Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong.
ACS Appl Mater Interfaces. 2020 Sep 16;12(37):42437-42445. doi: 10.1021/acsami.0c13631. Epub 2020 Sep 3.
Underwater gas-bubble manipulation in aqueous environments is of great importance in industry and academia. Although the underwater gas bubble has been proved to be directionally transportable by various structures, transporting gas bubbles in 3D space remains a challenge. In this research, two kinds of tapered pillars, that is, ladderlike and helical ladderlike, were proposed for manipulating gas bubbles. To fabricate such unique structures, an improved alternative coating and etching method was developed. To meet the requirements of underwater gas-bubble transport, a modified gas-bubble slippery technology was also developed to enhance the aerophilic ability. The dynamics of the gas bubble was analyzed using a high-speed camera. The Laplace force that resulted from the geometry gradient was found to play a significant role in tuning the gas-bubble velocity. Through adjustments on the wettability, tilt angle, and geometry of each section of the tapered pillar, tuning the transport velocity from 113.9 ± 10.3 to 309.1 ± 5.8 mm/s becomes possible. On the basis of these findings, the helical ladderlike tapered pillar was fabricated and demonstrated to be able to transport gas bubbles in 3D space. These results may provide a new and systematic way to design and fabricate materials and structures for directional gas-bubble transport in 3D space.
在水环境中对水下气泡进行操控在工业和学术界都具有重要意义。尽管已经证明水下气泡可通过各种结构进行定向传输，但在三维空间中传输气泡仍然是一项挑战。在本研究中，提出了两种锥形柱体，即阶梯状和螺旋阶梯状，用于操控气泡。为了制造这种独特的结构，开发了一种改进的交替涂层和蚀刻方法。为了满足水下气泡传输的要求，还开发了一种改进的气泡滑动技术以增强亲气能力。使用高速相机分析了气泡的动力学。发现由几何梯度产生的拉普拉斯力在调节气泡速度方面起着重要作用。通过调整锥形柱体各部分的润湿性、倾斜角度和几何形状，可以将传输速度从113.9±10.3毫米/秒调节到309.1±5.8毫米/秒。基于这些发现，制造出了螺旋阶梯状锥形柱体，并证明其能够在三维空间中传输气泡。这些结果可能为设计和制造用于三维空间中定向气泡传输的材料和结构提供一种新的系统方法。
