Demonstration of four fundamental operations of liquid droplets for digital microfluidic systems based on an electrowetting-on-dielectric actuator

摘要

An electrowetting-on-dielectric actuator is developed, in which the liquid is sandwiched between top and bottom plates. For the bottom plate, silicon wafer is used as the substrate, the heavily phosphorus-doped polysilicon film is deposited by low pressure chemical vapour deposition as the microelectrode array, and thermally grown SiO2 film as the dielectric layer. The top plate is a glass plate covered with transparent and conductive indium tin oxide as the ground electrode. In addition, a Teflon (R) AF1600 film is spun on the surface of both the plates as the hydrophobic layer. The experimental results show that when the gap height between two plates is 133 mu m, a prototype of the device is capable of creating, transporting, merging and dividing droplets of deionized water in an air environment with a 70 V at 10 Hz voltage pulse. This is also established by simulations using the computational fluidic software of CFD-ACE+.