Eco-friendly plasticized poly(vinyl chloride)-acetyl tributyl citrate gels for varifocal lens

We fabricated an eco-friendly, electroactive, reconfigurable, and varifocal PVC-ATBC (ePVC) gel lens. The ePVC gel lens, composed of PVC and environmentally-benign ATBC plasticizer, was reconfigured in response to applied voltage. The proposed ePVC gel lens, whose shape is hemispherical plano-convex, changes its curvature according to various input voltages, and the variation of its focal length was consequently observed. In addition, after removal of the electric field, the proposed electroactive and eco-plasticized ePVC gel lens showed rapid restoration to its initial configuration. Therefore, the focal length of the proposed ePVC gel lens could be considerably changed in real-time under an applied electric field. This is attributed to the electric-field-induced deformation of the eco-friendly plasticized non-ionic ePVC gel lens towards the anode under applied voltages, which changes the meniscus of the ePVC gel lens within a concentric annular anode electrode. As a result, the focal length of the ePVC gel lens in our system increased from 5 mm up to 15 mm with increasing applied voltages from 0 V to 500 V.