title: Insulating Material Requirements for Low-Power-Consumption Electrowetting-Based Liquid Lenses.
abstract: Insulating materials from the parylene family were investigated for use in low-power-consumption electrowetting-based liquid lenses. It was shown that for DC-driven operations, parylene C leads to hysteresis, regardless of the presence of a hydrophobic top coat. This hysteresis was attributed to the non-negligible time needed to reach a stable contact angle, due to charge injection and finite conductivity of the material. It was further demonstrated that by using materials with better insulating properties, such as parylene HT and VT4, satisfactory results can be obtained under DC voltages, reaching a low contact angle hysteresis of below 0.2°. We propose a simplified model that takes into account the injection of charges from both sides of the insulating material (the liquid side and the electrode side), showing that electrowetting response can be both increased and decreased.
authors.affiliation: Varioptic , 24B rue Jean Baldassini, 69007 Lyon, France.
authors.forename: Stéphanie
authors.identifier: 0000-0001-9091-0144
authors.initials: S
authors.lastname: Chevalliot
authors.affiliation: Varioptic , 24B rue Jean Baldassini, 69007 Lyon, France.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Malet
authors.affiliation: Haute Ecole Arc Ingénierie , Neode-Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds, Switzerland.
authors.forename: Herbert
authors.initials: H
authors.lastname: Keppner
authors.affiliation: Varioptic , 24B rue Jean Baldassini, 69007 Lyon, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Berge