Fig. 1. Schematic diagram of the tunable liquid lens driven by dielectric elastomer

Fig. 2. Contours of different membranes. (a) Contours of the active membrane under different initial liquid pressures; (b) contours of the lens membrane under different initial liquid pressures; (c) contours of the active membrane under different driving voltages; (d) contours of the lens membrane under different driving voltages

Fig. 3. Focal length of the liquid lens. (a) Liquid pressure and focal length of the liquid lens under different driving voltages; (b) focal length of the liquid lens under different initial liquid pressures and driving voltages

Fig. 4. Setup diagram of the experiment. (a) Measuring device for back focal length of the liquid lens; (b) theory and measurement results

Fig. 5. Influence of the Young's modulus on the focal length of the lens. (a) Relationship between the sagitta of the active membrane and the initial liquid pressure and driving voltage; (b) relationship between the sagitta of the lens membrane and the initial liquid pressure and driving voltage; (c) focal length of the liquid lens and the initial liquid pressure and driving voltage; (d) focal length of the liquid lens under different driving voltages

Fig. 6. Influence of the residual stress of the dielectric elastomer on the focal length of the lens. (a) Relationship between the focal length of the liquid lens and the initial liquid pressure and driving voltage; (b) focal length of the liquid lens under different driving voltages

Fig. 7. Influence of the thickness of the dielectric elastomer on the focal length of the lens. (a) Relationship between the focal length of the liquid lens and the initial liquid pressure and driving voltage; (b) focal length of the liquid lens under different driving voltages

Fig. 8. Influence of the radius of the dielectric elastomer on the focal length of the lens. (a) Relationship between the focal length of the liquid lens and the initial liquid pressure and driving voltage; (b) focal length of the liquid lens under different driving voltages

Table 1. Structural and material parameters of active and lens membranes

Table 2. Influence of different structural and material parameters of the dielectric elastomer on the focal length of liquid lens