椭球粒子受光诱导介电泳的数值模型

基于分子动力学提出了一种光诱导介电泳控制椭球粒子运动的数值模型.研究了光电芯片中椭球粒子承受的光诱导介电泳和斯托克斯阻力,采用Runge-Kutta方法计算不同长宽比粒子的自转速度.采用COM SOL有限元计算电场,借助Velocity-Verlet算法模拟了粒子受介电泳的运动轨迹.仿真结果表明,粒子长宽比越大,转速越快;在28,30μm位置处的椭球粒子,受正介电泳力向光斑运动,且沿着电场强度梯度方向行进,最高速度可达到312μm/s.以上仿真的转动速度和运动轨迹都与实验保持了较好的一致性.

Numerical Model for Ellipsoid Experiencing Optically Induced Dielectrophoresis

Based on the method of molecular dynamics， a numerical model was presented to simulate the behavior of such a ellipsoid experiencing optically induced dielectrophoresis (ODEP). The ODEP and Stokes force exerted on the ellipsoid were studied， and the Runge-Kutta method was used to calculate the self-rotation speed regarding different aspect ratio of ellipsoid. The electric field was solved by using COMSOL software， and the trajectory of the ellipsoid experiencing ODEP was simulated on the basis of the Velocity-Verlet algorithm. The simulation results indicated that the greater particle aspect ratio， the faster the speed. The ellipsoid at 28， 30μm location was controlled by the positive ODEP， which could move towards the light pattern along the gradient of the electric field magnitude， and the maximum speed could reach 312μm/s. The simulations results of the rotation speed and the trajectory are consistent with those in the experiment.