Tunable Liquid Lenses: Emerging Technologies and Future Perspectives

Abstract Tunable liquid lenses with controllable focal length attract much attention from many researchers due to the unique advantages of strong adjustability, low power consumption, fast response time, and easy integration. In the last two decades, tunable liquid lenses have already been applied in machine vision, code scanner cameras, cellphone cameras, webcams, microscopes, mini projectors, AR/VR displays, 3D displays, and so on. There is no doubt that the tunable liquid lenses play an increasingly more important role in the field of optical technology. In this review, the research background and significance of the tunable liquid lenses are introduced. Tunable liquid lenses are systematically qualified according to the driving mechanism, and their current status and latest progress are presented in detail. The existing problems, directions for future research, and current and potential applications of the tunable liquid lenses are also discussed.