Bioinspired tunable optics for artificial vision systems

Optical lenses with electrically tunable focus are needed for artificial vision systems in several fields of application, such as devices for machine/computer vision and, with a much longer perspective, bionic eyes for visual prostheses. Focal length tuning is usually obtained by displacing one or more constant-focus lenses. Owing to the need for moving parts, miniaturization of such systems is typically complex, and results in bulky, ineffective and expensive structures. To overcome these drawbacks, here we report on electrically tunable lenses made of dielectric elastomers as an emerging class of ‘artificial muscle’ materials. The lenses are inspired to the crystalline lens and ciliary muscle of the human eye, as well as to the tunable corneas of some animal eyes. Our devices have compact size, low weight, fast and silent operation, shock tolerance, low power consumption, no overheating, and can be implemented with inexpensive materials. Results suggest that combining bioinspired design with elastomeric artificial muscles has the potential to open new perspectives on tunable optics. We also anticipate that combining bioinspired pre-retinal optical processing based on such devices with photo-electric transduction over surfaces having tunable curvature might allow for optimal image detection and reconstruction. This attention for the hardware processing of the optical information is aimed at enhancing consolidated efforts from many groups on post-detection software processing, so as to overcome inherent limitations of approaches purely based on image elaboration.