The master's thesis addresses conceptual system of digital microfluidics that allows the discrete droplet manipulation by applying an electrical voltage. Applied electrical potential to the electrodes, on which the droplet is positioned, causes a change in contact angle, resulting in a droplet movement. The development of digital microfluidics in the mechanical engineering industry focuses primarily on the field of thermal management as a response to rapid advances in the electronics industry. Conventional thermal management methods no longer fulfill thermal requirements of advanced systems. Digital microfluidics based on the manipulation of discrete droplets is considered a promising solution for the dissipation of high-density heat fluxes and non-uniform temperature distribution inside closed electronic devices. In the beginning, chapters of the master's thesis theoretical fundamentals of surface tension and electrowettability are described. Typically used materials and the most common concepts of devices exploiting the phenomenon of electrowetting on dielectric (EWOD) are presented. The design and fabrication process of an open EWOD device using the principle of electrowetting on dielectric is described in detail. The process of fabricating a device includes the geometry design of the electrodes and the fabrication itself on the surface. In the fabrication of the electrodes, the technique of photolithography was used. An electrical insulation layer and a hydrophobic layer were applied on the surface of the electrodes. At the end of the master thesis, the experimentally obtained results are presented and compared with the simulation results. Based on the measurement analysis, a validation of the numerical model was performed. A device was designed to work with water, allowing an initial contact angle of 115° and reaching a contact angle of 80°. The device voltage limit is 175 V. Measurement results prove reaching velocity above 80 mm/s, which is also confirmed by the simulations of the numerical model.
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