A liquid lens is an advanced optical element that uses liquid materials as the refractive medium. By applying external stimuli such as electric fields, magnetic fields, or temperature changes, the surface shape of the liquid can be dynamically altered, enabling real-time adjustment of focal length, focus position, or aperture size. Unlike traditional lenses that rely on mechanical adjustment, liquid lenses offer advantages such as fast response, compact size, and high integration potential. They are widely applicable in optical imaging, biomedical fields, and industrial inspection.