Fabrication and Demonstration of Electrowetting Liquid Lens Arrays

Reported is the fabrication and demonstration of an array of >12 000 switchable liquid microlenses, each ~300 mum in diameter and switchable through plano-concave to plano-convex. Electrowetting is used to modulate the contact angle of an aqueous/oil liquid system over a range of 100deg, resulting in a switchable dioptric range of -360 m^-1 to 230 m^-1. Compared to previous reports of single 2-6 mm electrowetting lenses, the fabrication process reported herein reduces the individual lenslet size by ~10times. To dose liquids into large arrays of these small liquid lenslets, a scalable self-assembled dosing process was developed. The completed liquid lens array has a fill factor of 50% which can be extended to >80%.