Variable-focus flexible cylindrical lens based on near-infrared light-driven liquid crystal elastomers

This study explores a flexible cylindrical lens driven by near-infrared (NIR) light at 1200 mW and 808 nm. The design combines liquid-crystal elastomers (LCEs), as the driving component, with a highly transparent, deformable, and stable PDMS-based flexible cylindrical lens. The aim is to achieve a wide variable-focus range and high-quality focusing through light-driven methods. The initial structure of the flexible cylindrical lens was designed through theoretical calculations and simulation modeling. The lens itself was fabricated via thermoforming by mold injection PDMS, yielding an initial structure with an aperture diameter 2D' = 16 mm, thickness d = 1 mm, and width h = 4 mm. Under a single-sided stretch of 3 mm, the variable-focus distance reached 51.3 mm. The imaging system, based on the flexible cylindrical lens, achieved a variable-focus distance of 31.2 mm within a single-sided stretch range of 2 mm, maintaining an MTF_0.5 greater than 57.61 lp/mm, demonstrating high contrast and resolution. With the integration of LCEs as the driving component, a non-contact, NIR-light-driven variable-focus range of 10.35 mm was achieved within 25 s. This work highlights the application of NIR-light-driven LCEs within a variable-focus flexible cylindrical lens, providing new ideas and technical support for the development of future optical variable-focus devices.