Simulation of electric field strength in liquid lens from the concentric interdigitate electrode pattern

In this paper, the electric field distribution in designed liquid lens were simulated and demonstrated. The concentric interdigitate electrode was designed to generate the non-uniform electric field. Consequently, two liquid material on electrode undergoes dielectrophoresis (DEP) phenomenon and forming curvature can confine the incident light. Such two immiscible liquids were studied in the criteria of significant difference in dielectric constant such as Δε≈20. To be specific, the higher dielectric constant liquid as a lens material was first considered comparing to the ambient one. The simulation results reveal that, with fixed electrode width of 25 µm, the increasing gap of electrode from 25 to 125 µm can increase electric field strength at the lens apex from 237 to 386 V/m. Interestingly, the electric field strength was enhanced up to 533 V/m when the electrode width was increased. When the lower dielectric constant liquid was used as lens material, the electric field strength at the fixed width of 25 µm was increased from 16 to 71 V/m as the increasing gap from 25 to 125 µm. However, the low electric field strength of 63 V/m was obtained at broaden width of electrode. In both cases, the electric field strength is not significantly increased at the larger width for all conditions. Our model can be benefit for promising liquid lens design in term of low energy, cost reduction and compact device.