A nanocomposite thin film of Barium Strontium Titanate (BST) and Teflon®AF is synthesized to make a low voltage operation electrowetting-on dielectric (EWOD) device.
Analysis by conventional film characterization techniques show smooth, uniform and crack free hydrophobic film (contact angle ≈ 115°) with high dielectric constant (ɛr ≈ 9.1).
We fabricated EWOD devices with the nanocomposite thin film, and demonstrated contact angle modulation, droplet oscillation, and droplet transport (three most common operation of digital microfluidic devices).
The device is able to transport liquid droplet of 5 μl on coplanar electrodes at 30 V, and does not require an additional top hydrophobic layer.
The work avoids expensive and complex procedure of EWOD device fabrication, and can be done in low temperature (80 °C) only. Hence low melting point substrate and electrode material can be used for device, which makes fabrication economical.