Magnetic actuation on digital microfluidic (DMF) platforms may provide a low-cost, less cumbersome alternative for droplet manipulation in comparison to other techniques such as electrowetting-on-dielectric. Precise control of droplets in magnetically driven DMF platforms is achieved using a low-friction surface, magnetically susceptible material/droplet(s), and an applied magnetic field. Superhydrophobic (SH) surfaces offer limited friction for aqueous media as defined by their high water contact angles (WCA) (>150°) and low sliding angles (<10°). The low surface friction of such coatings and materials significantly reduces the force required for droplet transport. Here, we present a study that examines several actuation parameters including the effects of particle and particle-free actuation mechanisms, porous and non-porous SH materials, surface chemistry, droplet speed/acceleration, and the presence of surface energy traps (SETs) on droplet kinematics. Automated actuation was performed using an XY linear stepper gantry, which enabled sequential droplet actuation, mixing, and undocking operations to be performed in series. The results of this study are applied to a quantitative fluorescence-based DNA assay in under 2 min.

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与诸如电介质上电润湿之类的其他技术相比，数字微流体（DMF）平台上的磁驱动可以为液滴操作提供低成本，少麻烦的替代方案。使用低摩擦表面，易受磁性影响的材料/液滴以及所施加的磁场，可以实现磁性驱动DMF平台中液滴的精确控制。超疏水（SH）表面为水性介质提供的摩擦力有限，这取决于其高水接触角（WCA）（> 150°）和低滑动角（<10°）。这种涂层和材料的低表面摩擦力显着降低了液滴运输所需的力。在这里，我们进行了一项研究，研究了几个驱动参数，包括颗粒和无颗粒驱动机制，多孔和无孔SH材料的影响，表面化学，液滴速度/加速度以及液滴运动学上存在表面能阱（SET）。使用XY线性步进机架执行自动驱动，这使连续的液滴驱动，混合和脱壳操作能够串行执行。这项研究的结果将在2分钟内应用于基于荧光的定量DNA分析。

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