Parsi Behzad, Gunn Max R, Winters Jacob V, Maynes Daniel, Crane Nathan B
Department of Mechanical Engineering, Brigham Young University, 350 Engineering Building, Provo, UT 84602, USA.
Micromachines (Basel). 2024 Dec 13;15(12):1491. doi: 10.3390/mi15121491.
Recent advancements in Electrowetting on Dielectric (EWOD) systems, such as simplified fabrication, low-voltage actuation, and the development of more reliable materials, are expanding the potential applications of electrowetting actuators. One application of EWOD actuators is in RF devices to enable dynamic reconfiguration and allow real-time adjustments to frequency and bandwidth. In this paper, a method is introduced to actuate a panel using EWOD forces. In the EWOD system, the velocity of the plate increases by maximizing the actuation force, minimizing the moving mass (droplets and metalized plate), and reducing resistance (contact line drag, fluid drag). However, some of these are competing factors. For instance, the actuation force can be increased by increasing the number of droplets, but this also increases the inertia and the drag force. An analytical model of EWOD actuation is presented to understand system performance tradeoffs. The model is validated with an EWOD experiment, and the data demonstrate less than a 7.8% error between the measured and predicted maximum plate velocities for different voltage inputs. In addition, this study presents a 3D numerical FEM model to analyze the velocity profile and viscous force in the thin droplets, focusing on variations along the droplet's height, which cannot be captured experimentally. The main advantage of the proposed system over previous works is the simple 2D manufacturing process, which allows embedding metalized plates and RF circuit boards, in addition to being compact, portable, and low-cost. In addition, the proposed method does not have any mechanical components, which can increase the system's reliability in a harsh environment.
介电电泳（EWOD）系统的最新进展，如简化制造、低电压驱动以及更可靠材料的开发，正在扩大电润湿致动器的潜在应用。EWOD致动器的一个应用是在射频设备中实现动态重新配置，并允许对频率和带宽进行实时调整。本文介绍了一种使用EWOD力驱动面板的方法。在EWOD系统中，通过最大化驱动力、最小化移动质量（液滴和金属化板）以及降低阻力（接触线阻力、流体阻力）来提高板的速度。然而，其中一些是相互竞争的因素。例如，通过增加液滴数量可以增加驱动力，但这也会增加惯性和阻力。提出了一个EWOD驱动的分析模型来理解系统性能的权衡。该模型通过EWOD实验进行了验证，数据表明对于不同电压输入，测量和预测的最大板速度之间的误差小于7.8%。此外，本研究提出了一个三维数值有限元模型来分析薄液滴中的速度分布和粘性力，重点关注沿液滴高度的变化，这是实验无法捕捉到的。与以前的工作相比，所提出系统的主要优点是简单的二维制造工艺，除了紧凑、便携和低成本外，还允许嵌入金属化板和射频电路板。此外，所提出的方法没有任何机械部件，这可以提高系统在恶劣环境中的可靠性。
