Electrowetting: a convenient way to switchable wettability patterns

摘要: Electrowetting is a versatile tool to reduce the apparent contact angle of partially wetting conductive liquids by several tens degrees via an externally applied voltage. We studied various fundamental and aspects equilibrium liquid surface morphologies both theoretically experimentally. Our theoretical analysis showed that profiles on homogeneous surfaces display diverging curvature in vicinity three phase line. The asymptotic at line equal Young's angle, independent With respect morphology surface, variations achieved electrowetting are equivalent those varying chemical nature substrates, except for electric field-induced distortions region close Experimentally, we (global) microstructure substrates with stripe-shaped electrodes. As local reduced increasing voltage, droplets elongate along stripe axis as expected. For single electrode, there discontinuous morphological transition where elongated transform into translationally invariant cylinder segments pinned edge vice versa. If confined between two parallel electrodes, elongation droplet its transformation lines continuous. Experimental results compared analytical numerical models.