介电湿润芯片上液滴从静止到运动的机理

Mechanism of Droplets from Stationary to Moving on Electrowetting-on-dielectric Chips

针对介电湿润芯片上液滴在电场作用下的运动过程,对液滴从静止到运动的机理进行了研究。根据电磁极化原理并结合克劳修斯-莫索提方程对固液接触面的极化机理进行了研究,在极化性与介电常数之间建立了一个连接。应用COMSOL Multiphysics多物理场仿真软件对芯片中的电场进行建模和数值仿真,分析了芯片中电场强度和麦克斯韦应力张量对液滴受力的影响,建立了液滴内部流体静压力差公式,分析了液滴的运动过程和机理。最后,通过实验验证了液滴的运动过程。

Aiming at the problems that the moving processes of droplets on electrowetting-on-dielectric chips under electric fields,the mechanism of droplet moving from stillness to motion was studied.Based on the principle of electromagnetic polarization and Clausius-Mosotti equation,the polarization mechanism of solid-liquid interface was analyzed,and the connection between polarization and dielectric constant was established.Then,the electric field was modeled and simulated by means of COMSOL Multiphysics software.The influences of electric field intensity and Maxwell stress tensor on the forces of droplet in the chips were analyzed.In addition,the equation of hydrostatic pressure difference inside the droplets was obtained,and the moving processes and mechanism of droplets were analyzed.Finally,the moving processes of droplet were verified by experiments.