Abstract： The entrapment of bacteria near boundary surfaces is of biological and practical importance, yet the underlying physics is not well understood. We demonstrate that it is crucial to include a commonly neglected entropic effect related to the spatial variation of hydrodynamic interactions, through a model that provides analytic explanation of bacterial entrapment in two dimensionless parameters: α₁ the ratio of thermal energy to self-propulsion, and α₂ an intrinsic shape factor. For α₁and α₂ that match an Escherichia coli at room temperature, our model quantitatively reproduces existing experimental observations, including two key features that have not been previously resolved: The bacterial “nose-down” configuration, and the anticorrelation between the pitch angle and the wobbling angle. Furthermore, our model analytically predicts the existence of an entrapment zone in the parameter space defined by {α₁, α₂ }.

主讲人简介：徐辛亮，北京计算科学研究中心研究员，博士生导师。研究领域为统计物理和软凝聚态物理，致力于探索软物质体系丰富的结构性质背后的统计物理基本规律。于2002年在清华大学物理系获得学士学位，2007年在芝加哥大学物理系获得博士学位。随后在麻省理工学院进行博士后工作。自2014年在北京计算科学研究中心工作，主要研究体系包括活性体系、胶体体系。