Polymethyl methacrylate (PMMA)/fluoropolymer bilayer: a promising dielectric for electrowetting applications

We present electrowetting (EW) on a Bilayer Dielectric Stack (BDS) made from PMMA polymer and a top layer of fluoropolymer. The effective capacitance of such BDS is inversely proportional to the layer thickness. The EW response was analyzed on distinct BDS surfaces where the PMMA layer thickness was varied from a few nanometers to micrometer, and the top layer thickness was kept fixed at 20 nm. The highest value of the effective capacitance, epsilon(eff )similar to( )3, was recorded on a BDS for PMMA layer thickness d(p) similar to 0.8 mu m with Fluoropel (R) thickness d(F) = 20 nm. The BDS surface showed consistent EW response for ac as well as for dc-voltages without any EW hysteresis. As a proof of concept, the BDS was utilized on the conductive electrodes of the liquid lens and successfully achieved the manipulation of the oil-liquid interface leading to the magnification of the object placed at the focal plane. [GRAPHICS] .

Automated summary

In this study, electrowetting on a bilayer dielectric stack (BDS) made from PMMA and fluoropolymer was investigated. The effective capacitance of the BDS was found to be inversely proportional to the layer thickness. The BDS showed consistent electrowetting response on different surfaces with varied PMMA layer thickness, and was successfully used to manipulate the oil-liquid interface on a liquid lens.