Liquid lens with a large aperture and a wide zoom range by using a flexible retractable pipe

In this work, a large-aperture and wide zoom range liquid lens based on a flexible retractable pipe is proposed. It mainly consists of a flexible corrugated pipe, transparent filling liquid, elastic film, and electromagnetic actuator. By applying different currents, the pipe stretches or compresses along the axial direction, changing the curvature of the elastic membrane instead of driving by the filling liquid flow, and ultimately realizing the continuous tuning of the focal length. In the experiment, a 20 mm aperture liquid lens prototype is fabricated and tested. As the current changes from -300 to 300 mA, the negative focal length varies from -∞ to -46.25m m, while the positive focal length ranges from 44.25 mm to +∞. When the current is 300 mA, the lens achieves 45.30 lp/mm resolution and exhibits 1.73× magnification. Additionally, its response time is less than 8 ms.