This paper presents an electrical actuation scheme of dielectric droplet by negative liquid dielectrophoresis. A general model of lumped parameter electromechanics for evaluating the electromechanical force acting on the droplets is established. The model reveals the influence of actuation voltage, device geometry, and dielectric parameter on the actuation force for both conductive and dielectric medium. Using this model, we compare the actuation forces for four liquid combinations in the parallel-plate geometry and predict the low voltage actuation of dielectric droplets by negative dielectrophoresis. Parallel experimental results demonstrate such electric actuation of dielectric droplets, including droplet transport, splitting, merging, and dispending. All these dielectric droplet manipulations are achieved at voltages < 100 V_rms. The frequency dependence of droplet actuation velocity in aqueous solution is discussed and the existence of surfactant molecules is believed to play an important role by realigning with the AC electric field. Finally, we present coplanar manipulation of oil and water droplets and formation of oil-in-water emulsion droplet by applying the same low voltage.

中文翻译：

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负液体介电泳对介电液滴的电驱动

本文提出了一种通过负液体介电泳对介电液滴进行电驱动的方案。建立了用于评估作用在液滴上的机电力的集总参数机电模型。该模型揭示了驱动电压、器件几何形状和介电参数对导电和介电介质的驱动力的影响。使用该模型，我们比较了平行板几何形状中四种液体组合的驱动力，并通过负介电泳预测介电液滴的低压驱动。平行实验结果证明了介电液滴的这种电驱动，包括液滴传输、分裂、合并和分配。所有这些介电液滴操作都是在 < 100 V 的电压下实现的_有效值。讨论了水溶液中液滴驱动速度的频率依赖性，并且认为表面活性剂分子的存在通过与交流电场重新排列而发挥重要作用。最后，我们提出了通过施加相同的低电压对油滴和水滴进行共面操纵以及水包油乳液滴的形成。