Abstract
In nature, fishes have evolved functional skins with effective
hydrodynamic performance to reduce water resistance, anti-fouling,
facilitating predation and escaping from predators. Although a large
number of fish scale-inspired structured surfaces have been explored,
the incorporation of mucus on the structured surfaces has been largely
ignored. Inspired by the skins of Osteichthyes fishes, a Janus hydrogel
coating (JHC) is successfully prepared by a two-step UV light
irradiation at room temperature. The bottom side of JHC (STH) achieves a
shear adhesive strength of 103.3 ± 17.5 kPa and can strongly adhere to a
large variety of surfaces, including metals, ceramic and polymers. The
top surface of JHC (SLH) replicates the structure of cycloid scales,
while the nature of hydrogel mimics the mucus on fish skin. SLH
possesses prominent mechanical, anti-swelling, anti-fouling and drag
reduction properties. The design strategy for JHC has potential
applications in numerous fields, like, pipeline transportation,
bioengineering, and shipping industry.