Frozanpoor Iman, Cooke Michael D, Ambukan Vibin, Gallant Andrew J, Balocco Claudio
Department of Engineering, Durham University, South Rd, Durham DH1 3LE, U.K.
Langmuir. 2021 Jun 1;37(21):6414-6422. doi: 10.1021/acs.langmuir.1c00329. Epub 2021 May 20.
This work develops a technology for actuating droplets of any size without the requirement for high voltages or active control systems, which are typically found in competitive systems. The droplet actuation relies on two microelectrodes separated by a variable gap distance to generate an electrostatic gradient. The physical mechanism for the droplet motion is a combination of liquid dielectrophoresis and electrowetting. Investigating the system behavior as a function of the driving frequency identified the relative contribution of these two mechanisms and the optimum operating conditions. A fixed signal frequency of 0.5 kHz actuated various liquids and contaminants. Droplet actuation was demonstrated on several platforms, including linear, radial-symmetric, and bilateral-symmetric droplet motion. The electrode designs are scalable and can be fabricated on a flexible and optically transparent substrate: these key advancements will enable consumer applications that were previously inaccessible. A self-cleaning platform was also tested under laboratory conditions and on the road. This technology has significant potential in microfluidics and self-cleaning platforms, for example, in the automotive sector to clean body parts, camera covers, and sensors.
这项工作开发了一种驱动任何尺寸液滴的技术，无需高电压或有源控制系统，而这些在竞争系统中通常是必需的。液滴驱动依赖于由可变间隙距离隔开的两个微电极来产生静电梯度。液滴运动的物理机制是液体介电泳和电润湿的组合。研究系统行为作为驱动频率的函数，确定了这两种机制的相对贡献以及最佳操作条件。0.5 kHz的固定信号频率可驱动各种液体和污染物。在包括线性、径向对称和双侧对称液滴运动在内的多个平台上展示了液滴驱动。电极设计具有可扩展性，并且可以在柔性和光学透明基板上制造：这些关键进展将实现以前无法实现的消费应用。还在实验室条件下和道路上测试了自清洁平台。该技术在微流体和自清洁平台方面具有巨大潜力，例如在汽车领域用于清洁车身部件、摄像头盖和传感器。
