Analysis of droplet mixing and splitting operations by a low actuation voltage electrowetting-on-dielectric device

This paper presents an electrowetting-on-dielectric (EWOD)-based droplet mixing and splitting device. In the proposed method, the droplet is sandwiched between the bottom and top substrate plates of the EWOD device. A dielectric layer of Parylene C and a thin coating of a hydrophobic Teflon layer are used to create the EWOD device. The device actuates the droplets by applying an electric potential and thus increases the wettability of the droplet on the EWOD surface. The Finite Element Method (FEM) based Coventorware software is used to accomplish the simulations. The simulated result shows that a significant change in contact angle (120° to 80°) of the droplet is occurred during the operations of both mixing and splitting. The EWOD device with Parylene C layer of 2 μm thickness and Teflon layer of 50 nm thickness started both droplet mixing and splitting operations at a low actuation voltage of 30 V.