Direct measurement of three-body interactions

Many-Body Force and Mobility Measurements in Colloidal Systems

We demonstrate a technique for simultaneously measuring each component of the force vectors and mobility tensor of a small collection of colloidal particles based on observing a set of particle trajectories. For a few-body system of micron-sized polymer beads in oil separated by several particle radii, we find that the mobility tensor is well-described by a pairwise Stokeslet model. This stands in contrast to the electrostatic interactions, which were found to deviate significantly from a pairwise model. The measurement technique presented here should be simple to extend to systems of heteroge…

利用光镊直接实验测量多体流体动力学相互作用

Direct experimental measurement of many-body hydrodynamic interactions with optical tweezers

针对多体流体动力学相互作用（HIs）缺乏实验量化框架的问题，本研究设计光镊实验方法，通过平动-转动耦合捕获信号，测量了少体到多体HIs特性，结果与理论及模拟一致，还扩展框架操纵胶体尺度流。

Direct numerical simulations of rigid body dispersions. I. Mobility/Friction tensors of assemblies of spheres

An improved formulation of the Smoothed Profile method is introduced to perform direct numerical simulations of arbitrary rigid body dispersions in a Newtonian host solvent. Previous implementations of the method were restricted to spherical particles, severely limiting the types of systems that could be studied. The validity of the method is carefully examined by computing the friction/mobility tensors for a wide variety of geometries and comparing them to reference values obtained from accurate solutions to the Stokes-Equation.