Fig. 1. Structral diagrams of the double-interface liquid lens based on combination structure

Fig. 2. Simulation flow chart of the double-interface combined liquid lens modeling using software

Fig. 3. The double-interface combined liquid lens modeling with Comsol software

Fig. 4. Schematic diagrams of droplet pattern changes fitted with Comsol under different voltages

Fig. 5. Schematic diagrams of the fitted surface of droplet interfaces under different voltages

Fig. 6. Fitting graphs of PDMS membrane fitted with Matlab under different volumes of injected liquid. Volume of injected liquid are (a) 0.05 mL and (b) 0.3 mL

Fig. 7. Optical path diagrams of the combined liquid lens without injected liquid (0 mL) and membrane non-deformation under different voltages

Fig. 8. Optical path diagrams of the combined liquid lens at the same voltage (200 V) under different volumes of injected liquid

Fig. 9. Physical drawing of the double-interface liquid lens based on combined structure. Volume of injected liquid are (a) 0 mL and (b) 0.2 mL

Fig. 10. Surface variation of the combined liquid lens at different voltages

Fig. 11. Comparison of variable focal length range of the combined liquid lens without injected liquid (0 mL) and membrane non-deformation in simulation and experiment at different voltages

Fig. 12. Comparison of variable focal length range of the combined liquid lens in simulation and experiment at the same voltage (200 V) under different injection volumes

Fig. 13. Resolution diagrams of the double-interface combined liquid lens at different voltages under different injection volumes