[Fluidis and Plasmas] Fluid Flow and Mixing Induced by AC Continuous Electrowetting of Liquid Metal
In this work, we proposed a novel design of microfluidic mixer utilizing the amplified Marangoni chaotic advection induced by AC continuous electrowetting of a metal droplet situated in electrolyte solution, due to the linear and quadratic voltage-dependence of flow velocity at small or large voltages, respectively. Unlike previous researchers exploiting the unidirectional surface stress with DC bias at droplet/medium interface for pumping of electrolyte where the resulting flow rate is linearly proportional to the field intensity, dominance of another kind of dipolar flow pattern caused by local Marangoni stress at the drop surface in sufficiently intense AC electric field is demonstrated by both theoretical analysis and experimental observation, which exhibits a quadratic growth trend as a function of the applied voltage. The dipolar shear stress merely appears at larger voltages and greatly enhances the mixing performance by inducing chaotic advection between the neighboring laminar flow. The mixer design developed herein, on the basis of amplified Marangoni chaotic advection around a liquid metal droplet at larger AC voltages, has great potential for chemical reaction and MEMS actuator applications, because of generating high-throughput and excellent mixing performance at the same time.
Qingming Hu 1,2 , Yukun Ren 1,3,* , Weiyu Liu 1 , Xiaoming Chen 1 , Ye Tao 1 , Hongyuan Jiang 1,3,*
School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang 150001, China
School of Mechatronics Engineering, Qiqihar University, Wenhua Street 42, Qiqihar, Heilongjiang 161006, China
State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang 150001, China
Hu, Q.; Ren, Y.; Liu, W.; Chen, X.; Tao, Y.; Jiang, H. Fluid Flow and Mixing Induced by AC Continuous Electrowetting of Liquid Metal Droplet. Preprints 2017, 2017030059 (doi: 10.20944/preprints201703.0059.v1).