Fabrication and characterization of multiscale spherical artificial compound eye with self-cleaning and anti-icing properties

Abstract The self-cleaning and de-icing phenomenon is magical in nature, and of practical importance in daily life and industrial activities. The paper studies the inclined impact behaviour of drop on the various surfaces, i.e., micronano hierarchy and multiscale artificial compound eye (ACE). The droplet experiences first spreading, then retract, and finally detach from the surface with different contact time, which results from the different solid fraction tuned by chemical time. Moreover, the anti-icing property of the hierarchical surfaces was further demonstrated and discussed. Results show that the hierarchical surfaces endow excellent anti-icing properties compared with the planar surface. For reaction time of 40 min, the hierarchy has delay time of 800 s, which almost three times the planar surface. Further, curved ACE was fabricated by laser swelling, gas-assisted deformation and chemical growth. The nanohairs was fully covered on the surface of ACE. The imaging property was tested in the experiment. The nanohairs greatly enhance the hydrophobicity compared with the regular ACE. The contact angles for regular ACE and ACE with nanohairs was 105°and 160°, respectively. Besides the static hydrophobic performance, the dynamic dewetting behavior is also tested. For regular ACE, the contact droplets stick to the surface; while for ACE with nanohairs, the droplets fully detach the curved surface with a contact time of ∼ 8.75 ms for Weber number (We) of 66. These findings are believed to provide guideline for preparation of surfaces for both self-cleaning and anti-icing purposes and paves the way for practical applications of the ACE.