Barman Jitesh, Shao Wan, Tang Biao, Yuan Dong, Groenewold Jan, Zhou Guofu
Guangdong Provincial Key Laboratory of Optical Information Materials and Technology and Institute of Electronic Paper Displays South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China.
Micromachines (Basel). 2019 May 16;10(5):329. doi: 10.3390/mi10050329.
Electric field-based smart wetting manipulation is one of the extensively used techniques in modern surface science and engineering, especially in microfluidics and optofluidics applications. Liquid dielectrophoresis (LDEP) is a technique involving the manipulation of dielectric liquid motion via the polarization effect using a non-homogeneous electric field. The LDEP technique was mainly dedicated to the actuation of dielectric and aqueous liquids in microfluidics systems. Recently, a new concept called dielectrowetting was demonstrated by which the wettability of a dielectric liquid droplet can be reversibly manipulated via a highly localized LDEP force at the three-phase contact line of the droplet. Although dielectrowetting is principally very different from electrowetting on dielectrics (EWOD), it has the capability to spread a dielectric droplet into a thin liquid film with the application of sufficiently high voltage, overcoming the contact-angle saturation encountered in EWOD. The strength of dielectrowetting depends on the ratio of the penetration depth of the electric field inside the dielectric liquid and the difference between the dielectric constants of the liquid and its ambient medium. Since the introduction of the dielectrowetting technique, significant progress in the field encompassing various real-life applications was demonstrated in recent decades. In this paper, we review and discuss the governing forces and basic principles of LDEP, the mechanism of interface localization of LDEP for dielectrowetting, related phenomenon, and their recent applications, with an outlook on the future research.
基于电场的智能润湿操控是现代表面科学与工程中广泛应用的技术之一，尤其在微流体和光流体应用领域。液体介电泳（LDEP）是一种利用非均匀电场通过极化效应来操控介电液体运动的技术。LDEP技术主要用于微流体系统中介电液体和水性液体的驱动。最近，一种名为介电润湿的新概念被提出，通过这种概念，介电液滴的润湿性可以在液滴的三相接触线处通过高度局部化的LDEP力进行可逆操控。尽管介电润湿在原理上与介电质上电润湿（EWOD）有很大不同，但在施加足够高电压时，它有能力将介电液滴铺展成薄液膜，克服了EWOD中遇到的接触角饱和问题。介电润湿的强度取决于电场在介电液体内的穿透深度与液体及其周围介质介电常数之差的比值。自介电润湿技术问世以来，近几十年来在涵盖各种实际应用的领域取得了显著进展。在本文中，我们回顾并讨论了LDEP的支配力和基本原理、用于介电润湿的LDEP界面定位机制、相关现象及其近期应用，并对未来研究进行了展望。
