面向微系统的介电泳力微纳粒子操控研究

Microparticles manipulation based on dielectrophoresis in microsystem

微系统中低浓度微纳粒子的操控技术亟需改进和完善,介电泳(dielectrophoresis)在这一领域具有很大的潜力.以介电泳基本原理分析为基础,推导了介电泳力的复数表达式.综合分析了影响传统介电泳力和行波介电泳力的主要因素,并建立星型电极和平行电极阵列的二维理论模型,分别作为传统介电泳力和行波介电泳力的微纳粒子操控结构.设置相应的边界条件,利用实部、虚部耦合求解的方法,仿真计算两种电极上的介电泳力分布规律,为实验提供参数依据.以传统介电泳力为基础,利用星型电极进行微纳粒子收集实验;以行波介电泳力为基础,利用平行电极阵列进行微纳粒子的提升与定向驱动实验.对比分析可知,实验与理论以及仿真分析具有较好的一致性.结果表明,微系统中利用介电泳力能够有效地对微纳粒子进行相关操控.

Dielectrophoresis （DEP） has a high potential in the manipulation of low concentration microparticles in microsystem, which is an urgent project. The complex DEP expression was induced based on the basic DEP theory. The main factor of the conventional DEP force and the traveling wave DEP force was analyzed and 2D analytical model with star electrodes as well as parallel electrodes were founded in order to act as the manipulation construction of them. Boundary conditions were set and the real part and imaginary part were coupled to compute the DEP force. The DEP distribution of the two electrodes was simulated numerically in order to obtain the parameters for the experiment. Based on the conventional DEP force, the star electrodes were used to collect microparticles and based on the travelling wave DEP force, the parallel electrodes were used for microparticles lift and directional driving, respectively. Comparing the experimental results with theoretical and simulation analysis, they had a good agreement. The results show that DEP force can be used to manipulate microparticles effectively in microsystem.