Investigation on fabricating continuous vivid sharkskin surface by bio-replicated rolling method

Vivid sharkskin has been fabricated by a direct bio-replicated micro-imprinting method in previous studies, and the good drag-reducing effect has been validated in water tunnel. However, for surface of fluid is larger than the whole skin of shark, splicing and affixing steps are absolutely necessary. One hand, the complexity of process will be increased significantly, the other hand, the stress concentration produced by external flow will be produced on jointing seams, especially for those which are perpendicular to the flowing direction, the jointing surface will be destroyed at a high speed of flowing, and perhaps, the drag-reducing efficiency can be decreased. Therefore, how to manufacture continuous vivid sharkskin in a large area has become an urgent problem to be resolved. In this paper, for eliminating the influence of wedge angle on scaleʹs back, the sputtering and photo lithography processes are put into application and the continuous vivid sharkskin surface with good forming effect is fabricated by rolling process at last.