Large Stroke Microscale Actuators Based on Electrowetting

该奖项的研究目的是检验集总参数模型和基本比例定律可以预测微尺度电润湿致动器所施加的动态力的假设。为了实现这一目标，必须对液滴驱动过程中施加的力进行表征。在这项工作中使用的方法是分别表征静态条件下驱动系统的力和电特性。这些响应将被组合成等效的储能和阻尼效应，类似于传统机械执行器的动力学模型。将使用动态测试对模型进行评估和改进。微尺度的定位和驱动方法受到致动器相对较大的尺寸以及在不损坏小对象的情况下抓住和释放小对象的挑战的限制。当前定位和驱动小对象的方法仅限于小运动和/或需要大尺寸部件。该项目将通过采用从微流体中移动单个液滴的方法，使小液滴能够移动部件。如果成功，这项工作将为定位亚毫米级零件和高速度、高精度地驱动微尺度器件提供新的方法。然而，电润湿只使用容易制造的衬底和电源就可以很容易地驱动很远的距离。这种能力将促进许多微尺度系统的操纵和驱动。它可能特别适合于将由不同工艺和/或材料制成的小部件组装成具有比原位制造更高水平的性能的系统。潜在的应用包括组装能量收集设备、小型机器人和其他微电子机械系统。从这项提议中获得的知识也将有利于电润湿的其他应用，包括低成本的医疗诊断和显示应用。

The research objective of this award is to test the hypothesis that lumped parameter models and basic scaling laws can predict the dynamic forces applied by microscale electrowetting actuators. To realize this goal, the forces applied during droplet actuation must be characterized. The approach used in this work is to separately characterize the force and electrical characteristics of the actuation system under static conditions. These responses will be combined into equivalent energy storage and damping effects that are analogous to dynamic models of conventional mechanical actuators. The models will be evaluated and refined using dynamic testing. Microscale positioning and actuation methods are limited by the relatively large size of the actuators and the challenge of grasping and releasing small objects without damaging them. Current methods of positioning and actuating small objects are limited to small motions and/or require bulky macroscale components. This project will enable the use of small droplets to move parts by adapting methods for moving individual droplets from microfluidics. If successful, this work will provide new methods for positioning sub-millimeter parts and actuating microscale devices with high speed and precision. However, electrowetting can readily actuate large distances using only easily manufactured substrates and an electrical source. This capability will facilitate the manipulation and actuation of many microscale systems. It may be particularly suited for the assembly of small parts made from different processes and/or materials into systems with higher levels of performance than can be achieved through in-situ manufacturing. Potential applications include the assembly of energy harvesting devices, small scale robots, and other microelectromechanical systems. The knowledge from this proposal will also benefit other applications of electrowetting including low cost medical diagnostics and display applications.