Ice-phobic glass-substrate surfaces coated with polypeptides inspired by antifreeze protein

•We conducted experiments on the freezing of water disks in washers on polypeptide-coated surfaces.•The ice adhesion strength of the coated surfaces decreased by up to 67% compared with that of uncoated surfaces.•The coated surfaces could maintain their characteristics for up to 100 repetitions of the ice removal.•The transparency of the glass plate was not changed by the coatin. The development of ice-phobic glass-substrate surfaces for industrial applications, such as preventing the formation of ice on vehicle windshields, is important. We have previously developed a glass surface coated with a polypeptide whose amino acid sequence is identical to part of an antifreeze protein. For this polypeptide, we showed that the ice adhesion strength was reduced by the coexistence of smooth surface parts exposing hydrophobic amino-acid residues and protrusion surface parts exposing hydrophilic amino-acid residues. In this report, we improve the experimental methods and conduct experiments on the freezing of water disks in steel washers on polypeptide-coated and uncoated surfaces. Under constant cooling surface temperatures, the ice adhesion strength of the coated surfaces decreased by up to 67% when compared with that of uncoated surfaces. Atomic force microscopy observations of the polypeptide-coated glass revealed small and large protrusions on the surface, which were formed by the aggregation of polypeptide. These protrusions and the smooth surface are primarily responsible for the reduced ice adhesion strength. In addition, repeated freezing of the water disks on the surfaces revealed that the coated surfaces could maintain their characteristics for up to 100 repetitions. In addition, the transparency of the glass plate was not changed by the coating. Thus, this polypeptide coating technique should be suitable for improving deicing properties of windshields, traffic lights, and surveillance cameras.