Electrowetting on Micropillar Electrodes and its Application to Microfluidic Devices

摘要

Changes observed in electrowetting on gold electrodes were enhanced by forming the electrodes on micropillar structures. The change in wettability was enhanced as the diameter of the micropillars decreased and was 88 deg. with micropillars of 10 μm in diameter, while the change was 41 deg. on a smooth electrode. The microstructures also accelerated the change of the contact angle. The improved performance was also tested in microfludic devices. When a long electrode with micropillars was formed on the bottom surface, a liquid column was mobilized four-times faster than that in a flow channel with a smooth electrode. When used as a microvalve, the electrodes with micropillars could stop an intruding solution and showed faster switching.