Development of solvent-free green PVC gel based varifocal micro-lens

Abstract

Environmental issues are being addressed more intensely in today’s and future society. Concerning to this, the term ‘solvent-free’ conjures up a wide variety of innovations amongst the scientific community. Thus, it is necessary to develop environmentally benign green approaches in design engineering. In this communication, we reported the fabrication of solvent-free green polyvinyl chloride (gPVC) gel based electroactive varifocal micro-lens, which can dynamically tune its focal length under the applied input voltage. To develop gPVC gels, PVC powder was thermally treated by mixing stoichiometric quantity of an eco-friendly green plasticizer, acetyl tributyl citrate (ATBC). To obtain better control over the tunable optical properties, various gPVC gels were characterized and optimized gel was investigated. Consequently, gPVC gel with ATBC to PVC (15:1) ratio have showed an outstanding performance. Under the electrical stimulation, the focal length of the proposed lens has been demonstrated in a controlled manner. The results revealed that, the proposed varifocal micro-lens could change its focal length ∼27.5 mm and will be a valuable asset for the future consumer electronic equipment.