Physics of Complex Fluids, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
Phys Rev Lett. 2018 May 25;120(21):214502. doi: 10.1103/PhysRevLett.120.214502.
We show that electrowetting (EW) with structured electrodes significantly modifies the distribution of drops condensing onto flat hydrophobic surfaces by aligning the drops and by enhancing coalescence. Numerical calculations demonstrate that drop alignment and coalescence are governed by the drop-size-dependent electrostatic energy landscape that is imposed by the electrode pattern and the applied voltage. Such EW-controlled migration and coalescence of condensate drops significantly alter the statistical characteristics of the ensemble of droplets. The evolution of the drop size distribution displays self-similar characteristics that significantly deviate from classical breath figures on homogeneous surfaces once the electrically induced coalescence cascades set in beyond a certain critical drop size. The resulting reduced surface coverage, coupled with earlier drop shedding under EW, enhances the net heat transfer.
我们表明，通过使液滴对齐并增强聚并，具有结构化电极的电润湿（EW）显著改变了冷凝到疏水平面上的液滴的分布。数值计算表明，液滴的对准和聚并受由电极图案和所施加电压施加的与液滴尺寸相关的静电能量景观控制。EW 控制的凝结液滴的迁移和聚并显著改变了液滴总体的统计特性。一旦电诱导聚并级联在超过某个临界液滴尺寸后开始，尺寸分布的演化显示出自相似特征，与同质表面上的经典呼吸图案显著偏离。由此产生的表面覆盖率降低，再加上 EW 下较早的液滴脱落，增强了净热传递。
