title: Improvement in the breakdown properties of electrowetting using polyelectrolyte ionic solution.
abstract: We report the improvement in the breakdown properties of electrowetting using a mixture of poly(acrylic acid)  (PAA) polyelectrolyte and a surfactant (Tween 80, TW80). Onset of  breakdown was initially determined via visual observation and further verified by investigating impedance phase shift. Breakdown characteristics of the large-molecule ionic solution were compared with those of conventional electrolytes (Na(2)SO(4)) that produce small molecules. Experiments with various conductivities and hydrophobic coatings on a thin silicon nitride dielectric layer (∼500 Å) showed that the breakdown voltage of the PAA-TW80 system was at least two times higher than that of the Na(2)SO(4)-TW80 system. Our results demonstrate that defects in the dielectric and hydrophobic layers are less vulnerable to larger ionic molecules.
authors.affiliation: School of Mechanical and Aerospace Engineering, WCU, Seoul National University, San 56-1, Sillim, Gwanak, Seoul, Korea 151-742.
authors.forename: Seungyul
authors.initials: S
authors.lastname: Choi
authors.forename: Yongjoo
authors.initials: Y
authors.lastname: Kwon
authors.forename: Yoon-Sun
authors.initials: YS
authors.lastname: Choi
authors.forename: Eok Su
authors.initials: ES
authors.lastname: Kim
authors.forename: Jungmok
authors.initials: J
authors.lastname: Bae
authors.forename: Junghoon
authors.initials: J
authors.lastname: Lee