Fabrication of Hierarchical Micro/Nano Compound Eyes.

Fabrication of a hierarchical macro-/micro-/nano compound eye is presented in this paper. This bioinspired compound (BIC) eye is obtained by an integrated manufacturing technology that combines (i) nanoimprinting, (ii) picosecond laser swelling, and (iii) air-assisted deformation. The diameter and height of nanopillars, microlens, and macrobase can be controlled precisely by fine-tuning the process parameters. The multifunctional properties of the BIC eye, such as superhydrophobicity, antireflection, and other optical characteristics, are investigated. It is found that the microlens with nanopillars can effectively improve the surface wettability with a contact angle of 152° and contact angle hysteresis of 12°, and enhance transmittance by 2% over the wavelength range of 200-1200 nm. Moreover, the final hierarchical compound eye exhibits the excellent imaging properties and a wide field-of-view of 120° without distortion. These multifunctional properties will enable the widespread application of the compound eye in diverse real-time environmental conditions.