A New Design for Microfludic Quantitative Dispensing by Electrowetting-on-dielectric

10.6567/IFToMM.14TH.WC.OS10.003

Han-Lai Chen；Shih-Kang Fan

microdroplet generation ； dispensing ； EWOD

Proceedings of the 14th IFToMM World Congress

14th-2（2015 / 10 / 27）

532 - 535

英文

Fluid dispensing plays a large role in fixation and connection between multi micro parts with the development of the micro-electronic packaging industry. Most of current fluid dispensing technology depend on the principle of ＂capillary phenomenon＂ and are affected passively by the surface tension of the liquid itself. The size of the micro-dot is limited by liquid properties and environmental conditions, which is difficult to keep uniform. Concerning this problem, we consider applying external forces to generate same-size microdroplets. EWOD (electrowetting-on-dielectric) is an important electric force to manipulate objects on dielectric-coated electrodes. The applied voltage is consumed mostly in the dielectric layer to generate EWOD to drive droplets. A parallel-plate sandwich-structure device is demonstrated, the size of microdroplet is only determined by the area of the driving electrode on the bottom plate and the spacer between the top and bottom plate. Moreover, a special driving electrode pattern whose last driving electrode meets the chip's corner is designed, which can help droplet move to the corner, and then, the droplet will be dispensed if it touch the hydrophilic substrate.