采用FDTD法计算复杂微转子所受光力和光力矩

摘要

微转子是微机电系统(MEMS)的一个重要组成部分.为了能够设计、驱动具有复杂形貌的微转子,对其所受的光驱动力矩的光波动模型计算方法进行了研究.使用时域有限差分法分析微转子在光阱中散射光场的电磁场量,根据麦克斯韦尔力学张量方程得到微转子表面所受的力.最后,应用牛顿方程计算出其相应的旋转力矩和转速等信息.用基于此方法编写的模块化Matlab程序分析计算了一个本文设计制造的微转子,并与实验进行了比较,结果与200 r/min相符,表明此方法基本满足复杂形貌微转子驱动力计算要求,对设计微转子有着很好的应用前景.%The microrotor is an important part in a Micro-electro-mechanical System(MEMS).For designing and driving the microrotor,the theoretical arithmetic of a wave optical model is investigated.The Finite-differential Time-domain(FDTD)method is used to analyze the electric and magnetic intensity distributions of the scattered light on the surface of the microrotors,and the Maxwell's stress tensor is employed to calculate the force over the rotor surfaces.Finally,the rotor torque on rotation axis and the rotate speed are obtained base on Newton equation.The calculated results agree with the experiments in rotate speed of 200 r/min,which shows the arithmetic can satisfy the requirements of calculating the light-induced force and torque on a complex microrotor,and can used in microrotor design.