Y.H. Yeong, A. Milionis, I.S. Bayer, E. Loth
University of Virginia, United States
pp. 476 - 479
Keywords: receding angle, superhydrophobic, microscopic
Receding angles have been shown to have great significance when designing a superhydrophobic surface for applications involving self-cleaning. Although apparent receding angles under dynamic conditions have been well studied, the microscopic receding contact line dynamics are not well understood. Therefore, we present to the best of our knowledge, a first experimental investigation to measure the microscopic receding contact line dynamics of superhydrophobic surfaces with textured pillar and irregular surface features at micron length scales and at microsecond temporal resolution. A drop was set in motion on these surfaces so that its three-phase receding contact line dynamics could be recorded using a high speed camera fitted with high magnification optics for analysis. Results revealed that the receding line progressed from the lower edge of a pillar, across the length of the pillar top before “snapping” to advance to the adjacent pillar, creating a “slide-snap” motion. This is in contrast to the “stick-slip” motion that was reported in previous studies.