[NCTS Physics Research Highlights] Hsuan-Yi Chen & Pik-Yin Lai 'Avalanches and Extreme Value Statistics of a Mesoscale Moving Contact Line', Phys. Rev Lett. 132, 084003 (2024)

• 2024-03-11
• Chen, Jhan Yu 陳詹喻
• Chemical physics, physical chemistry, nanoscience and complex systems Interdisciplinary Research

Avalanches and Extreme Value Statistics of a Mesoscale Moving Contact Line 介觀尺度接觸線的雪崩與極值統計

Caishan Yan, Dongshi Guan, Yin Wang, Pik-Yin Lai*, Hsuan-Yi Chen*, and Penger Tong
Phys. Rev Lett. 132, 084003 (2024) [Editors' Suggestion]
DOI: https://doi.org/10.1103/PhysRevLett.132.084003

The pinning-depinning dynamics of a circular moving contact line (CL) over the rough surface of a micron-sized vertical hanging AFM glass fiber are analyzed.  The capillary force acting on the CL exhibits sawtooth-like fluctuations, with a linear accumulation of force of slope k (stick) followed by a sharp release of force δf, which is proportional to the CL slip length. We find that the local maximal force Fc needed for CL depinning follows the extreme value statistics and the measured δf follows the avalanche dynamics with a power law distribution in good agreement with the Alessandro-Beatrice-Bertotti-Montorsi model. The results provide an accurate statistical description of the CL dynamics at mesoscale, which has important implications to a common class of problems involving stick-slip motion in a random defect or roughness landscape.

我們分析了懸掛 AFM 玻璃纖維粗糙表面上接觸線 (CL) 的黏滑動力學。CL滑動所需的最大力遵循極值統計，測量的 δf 遵循雪崩動力學，其冪律分佈與 Alessandro-Beatrice-Bertotti-Montorsi 模型非常一致。結果提供了介觀尺度的 CL 動力學的準確統計描述，這對於涉及隨機缺陷或粗糙度景觀中的黏滑運動的常見問題具有重要意義。