Journal of Applied Polymer Science, Vol.130, No.4, 2383-2389, 2013
Large-scale equal-proportional amplification bio-replication of shark skin Based on solvent-swelling PDMS
Shark skin has attracted worldwide attention on its superior drag reduction, so-called shark skin effect. Such marvelous function of shark skin, in particular, is in part related to complicated micro-riblets. As the creation of natural evolution, micro-riblets of shark skin act out desirable drag reduction only within range of swimming speed. Over past few years, bio-replication approach which takes the shark skin as replica template to 1 : 1 transfer surface morphology has been widely applied for drag reduction. However, if application environment remarkably differs from living environment, the drag reduction function is attenuated or even becomes adverse, i.e., the surface structure nonadjustable to ambient environment is obstacle to widespread application of bio-replication. In this paper, large-scale equal-proportional amplification bio-replication approach is presented to adjust the micro-riblets of shark skin by taking solvent-swelling polymer as replica mould. Solvent-swelling property of polymer is investigated by controlling its swelling ratio to make natural surface function adapting to various application environment. Apart from higher replication accuracy about 95%, experiments show that about 140% solvent-swelling ratio is achieved at one-time amplification, and translation of drag reduction peak of natural surface function form living environment to various application environments is ensured by successive large-scale equal-proportional bio-replications. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2383-2389, 2013