Tunable lens using dielectric elastomer sandwiched by transparent conductive liquid

We propose and demonstrate a compact tunable lens with high transmittance using a dielectric elastomer sandwiched by transparent conductive liquid. The transparent conductive liquid not only serves as the refractive material of the tunable lens but also works as the compliant electrode of the dielectric elastomer. The overall dimensions of the proposed tunable lens are 16 mm in diameter and 10 mm in height, and the optical transmittance is as high as 92.2% at 380-760 nm. The focal power variation of the tunable lens is -23.71D at an actuation voltage of 3.0 kV. The rise and fall times are 60 ms and 185 ms, respectively. The fabrication process of the tunable lens is free of the deposition of opaque compliant electrodes. Such a tunable lens promises a potential solution in various compact imaging systems.