Researchers at the Georgia Institute of Technology in the United States have pioneered a bionic soft lens capable of automatically adjusting its focal length in response to ambient light intensity, closely mirroring the functionality of the human eye. This groundbreaking innovation leverages the photoresponsive hydrogel soft lens (PHySL) technology. The lens comprises a hydrogel matrix infused with light-absorbing graphene oxide, featuring a micro-lens at its core. Upon exposure to light, the graphene oxide absorbs the light energy, converting it into heat and causing the hydrogel to contract. This contraction, in turn, stretches the central micro-lens, altering its curvature and facilitating pupil dilation along with an extension of the focal length. Conversely, when the light intensity diminishes, the hydrogel cools down and reverts to its original shape, causing the lens to retract accordingly. Notably, this entire process operates without the need for an external power source or mechanical driving mechanism, achieving true autonomous adjustment.

The researchers successfully integrated the PHySL into a conventional bright-field microscope, enabling high-resolution imaging of various biological samples. The image quality achieved was on par with that of standard microscope objectives. Experiments have demonstrated that the PHySL can automatically adjust its focus under natural lighting conditions, making it well-suited for dynamic imaging of multi-layered samples. This innovation underscores the vast potential of light-driven soft materials in the development of adaptive vision systems, autonomously operating soft robots, intelligent medical devices, and next-generation wearable technologies. The relevant research findings have been published in the latest issue of the journal Science Robotics.