Lateral positioning of tunable liquid microlens with four coplanar electrodes

This paper presents an electro-wetting on dielectric (EWOD) based liquid lens which focal point is tunable axially and laterally as well. The conductive inner liquid for a variable focus is covered by another non-conductive liquid, which is spherically encapsulated by a thin layer of parylene. The lateral position of focal point is controllable using four fan-shaped coplanar electrodes. The tunable liquid microlens shows the maximum lateral movement of 340 μm with a negligible coupling to the other lateral direction.