BaTiO_3/Teflon Nanocomposite Ferroelectric Thin Films for Low Voltage Electrowetting Systems

摘要

We present a simple and cost effective method for the design and fabrication of electrowetting devices using a nanocomposite thin film of BaTiO_3 and Teflon-AF as the dielectric layer to achieve low voltage operation. The nanocomposite film is prepared by using Teflon-AF as matrix and BaTiO_3 nanoparticles as the filler material. The solution is spin coated to deposit thin film on metal electrodes. The characterization results show that the nanocomposite thin film can serve as the dielectric for EWOD with a high dielectric constant and a crack free hydrophobic film. To test the electrowetting effect, the variation of droplet contact angle achieved with DC voltage, AC voltage and AC frequency change are fully experimented. The EWOD device with nanocomposite dielectric layer also manipulates water droplet at low driving voltages. This study shows the potential of using ferroelectric nanocomposite film as the dielectric layer in high-performance EWOD devices.