Solution-Processed, In Situ Photopatternable Conducting Polymer Electrodes for High-Performance and Durable Electrowetting Displays

As an effective liquid manipulation technology, electrowetting refers to the phenomenon where a droplet can be attracted to and spread on a substrate under an external electric field. However, the corrosion of conventional ITO electrodes in high-humidity environments remains the key factor limiting their long-term operation. In this study, an in situ patterning strategy based on conductive polymers (PEDOT:PSS) has been proposed for constructing electrodes instead of ITO. Subsequently, dimethyl sulfoxide (DMSO) was applied to regulate the molecular configuration of PEDOT:PSS. This treatment induced a structural transformation from a benzoid to a quinoid structure, resulting in a drastic reduction in sheet resistance from 10,916 Ω/□ to 380 Ω/□. Furthermore, electrowetting reflective devices based on these photopatternable PEDOT:PSS electrodes were fabricated for the first time. These devices exhibited comparable onset potentials, response speeds, and maximum aperture ratios to those of the ITO-based control samples. Notably, during the thermal accelerated aging test (∼1.7 million on-off cycles), the cross-linked PEDOT:PSS electrodes demonstrated excellent operational stability with no obvious corrosion. This investigation of solution-processed, highly conductive, and corrosion-resistant organic electrodes provides technical support for the commercialization of efficient and stable electrowetting displays.