Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, Zurich CH-8092, Switzerland.
Laboratory for Multiphase Thermofluidics and Surface Nanoengineering, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, Zurich CH-8092, Switzerland.
Mater Horiz. 2022 Apr 4;9(4):1222-1231. doi: 10.1039/d1mh01993g.
Surface icing is detrimental to applications ranging from transportation to biological systems. Soft elastomeric coatings can engender remarkably low ice adhesion strength, but mechanisms at the microscale and resulting ice extraction outcomes need to be understood. Here we investigate dynamic ice-elastomer interfacial events and show that the ice adhesion strength can actually vary by orders of magnitude due to the shear velocity. We study the detailed deformation fields of the elastomer using confocal traction force microscopy and elucidate the underlying mechanism. The elastomer initially undergoes elastic deformation having a shear velocity dependent threshold, followed by partial relaxation at the onset of slip, where velocity dependent "stick-slip" micropulsations are observed. The results of the work provide important information for the design of soft surfaces with respect to removal of ice, and utility to fields exemplified by adhesion, contact mechanics, and biofouling.
表面结冰会对从交通运输到生物系统等各种应用造成危害。柔软的弹性体涂层可以产生极低的冰附着强度,但需要了解微观尺度的机制和由此产生的冰提取结果。在这里,我们研究了动态冰-弹性体界面事件,并表明冰附着强度实际上可以由于剪切速度而相差几个数量级。我们使用共焦牵引力显微镜研究了弹性体的详细变形场,并阐明了其潜在机制。弹性体最初经历具有剪切速度相关阈值的弹性变形,然后在开始滑动时部分松弛,在那里观察到速度相关的“粘滑”微脉动。这项工作的结果为设计具有除冰功能的软表面提供了重要信息,对粘附、接触力学和生物污垢等领域具有实用价值。