Bio-inspired eyes with eyeball-shaped lenses actuated by electro-hydrodynamic forces

Inspired by vertebrate eyes, electro-hydrodynamic forces functioning as the ciliary muscle of bio-inspired eyes are extremely appealing in micro-optical devices. Eyeball-shaped lenses, composed of a liquid-core-cladding microlens array (LCC-MLA) is firstly utilized to fabricate a bio-inspired eye array through electro-hydrodynamic actuation. In this work, when the applied voltage increases, the microlens shape evolves from spherical crown to LCC-MLA shape (prolate egg). When the applied voltage is removed, the microlens shape changes from prolate egg to sphere. At a result, the electro-hydrodynamic force difference upon the lens interface leads to the adjustment of lens curvature. In addition, bio-inspired eyes manifest reversible 6-fold zoom and a fast responding time (∼50 ms). In contrast with a traditional tunable lens, the LCC-MLA is closer to a biological shape with wide vari-focal ability by electro-hydrodynamic actuation. Herein, these excellent properties make LCC-MLA promising for optics-based imaging sensors.