Superhydrophobic Artificial Compound Eye with High Transparency.

Natural compound eyes have inspired the development of self-cleaning, waterproof, and antifog optical devices. However, the traditional methods generally sacrifice the transparency of optical units to introduce hydrophobicity, which significantly limits the practical applications of state-of-the-art hydrophobic technologies. This work aims to fabricate a microimaging system by combining photolithography, inkjet printing, and chemical growth. Herein, an artificial compound eye (ACE) is endowed with stable superhydrophobicity and high transparency without affecting its optical performance. The obtained ACE system possesses good static and dynamic dewetting properties along with excellent optical performance. Its static contact angle exceeds 160°, whereas the sliding angle and contact angle hysteresis values are ∼5.5° and ∼3.8°, respectively. Furthermore, the contact time is found to be 11.97 s for the Weber number of 12. The droplet undergoes a reversible process during compressing and stretching, and the ACE exhibits no adhesion under a pressure load of 4 mN. This proves that the introduction of nonwetting nanohairs on the sidewalls of the microcone arrays significantly improves the dynamic dewetting of the system. More importantly, the properly designed position of nanohairs ensures that the optical performance of ACE is maintained at a level of ∼95% compared to that of the bare glass. The superhydrophobic ACE exhibits low adhesion and great transparency. This rationally designed ACE may provide useful guidelines for fabrication of superhydrophobic optical devices with high transparency and enable potential applications in military, medical, and some outdoor activity fields.