Bioinspired tunable lens driven by electroactive polymer artificial muscles

Electrical control of optical focalisation is important in several fields, such as consumer electronics, medical diagnostics and optical communications. As an alternative to complex, bulky and expensive current solutions based on shifting constant-focus lenses, here we report on an electrically tunable lens made of dielectric elastomers as 'artificial muscle' materials. The device is inspired to the architecture of the crystalline lens and ciliary muscle of the human eye. A fluid-filled elastomeric lens is integrated with an annular elastomeric actuator that works as an artificial muscle. Electrical activation of the artificial muscle deforms the lens, with a relative variation of focal length comparable to that of the human lens. Optical performance is achieved with compact size, low weight, fast and silent operation, shock tolerance, no overheating, low power consumption, and inexpensive off-the-shelf materials. Results show that combing bio-inspired design with dielectric elastomer artificial muscles can open new perspectives on tunable optics.