An electrohydrodynamically actuated liquid microlens with areal density modulated electrodes

This paper reports an electrohydrodynamically actuated tunable liquid microlens with a novel electrode layout design, called areal density modulated electrodes. Compared to previously reported electrohydrodynamically actuated liquid microlenses, the proposed concept addresses both continuous tunability and centering of the microlens axis with a simple to fabricate, planar electrode structure. Based on the proposed concept, a microlens structure was designed. Preliminary electrostatic simulation was conducted that showed the effectiveness of the proposed concept. An electrowetting based microlens was fabricated and tested. The focal length of the microlens varied continuously from 33.7 mm to 6.4 mm as the applied voltage increased from zero to 120 V.