Fish Skin: A Thin, Flexible, Protective Membrane

Although there have been recent efforts to characterize the important structural characteristics of fish scales and fish skin (e.g., the tensile strength [9] , puncture strength [19], bending rigidity [10]), attempts to fabricate materials that mimic natural fish skins have remained limited. This thesis presents a synthetic fish skin material designed to replicate the structural, dimensional, mechanical, and functional aspects of natural teleost fish skin comprised of leptoid-like scales. The material design and fabrication has been simplified to include (i) a low modulus elastic mesh or dermis layer that holds (ii) relatively (in comparison to the mesh) rigid, plastic scales. While the mesh holds the scales in place even when the skin is deformed, the scales remain free to rotate and interact with neighboring scales or the substrate. The mechanics of the resulting material was quantified, using experiments and theoretical models, in response to in-plane deformations, flexure, and indentation. The mechanical behavior achieved with this design was found to be similar to that of natural fish skin, thus indicating the distinct roles that interacting dermal and scale layers have on the material properties. Overall the synthetic fish skin is flexible and can conformably cover a range of surfaces, including those subject to diverse modes of deformation, making such a material attractive as a low-weight, low-profile protective coating for soft materials.