Artificial shark skin with rigid denticles attached to a flexible membrane. Image © James Weaver
Shark skin is made of millions of microscopic ‘denticles’, overlapping tooth-like scales, to smooth flow of water over predator’s surface.
George Lauder from Harvard University, speaking to the Journal of Experimental Biology, said:
“After considering a number of approaches, we decided that the only way to embed hard denticles in a flexible substrate was the 3D printer.”
We present the first study of the design, fabrication and hydrodynamic testing of a synthetic, flexible, shark skin membrane. A three-dimensional (3D) model of shark skin denticles was constructed using micro-CT imaging of the skin of the shortfin mako (Isurus oxyrinchus). Using 3D printing, thousands of rigid synthetic shark denticles were placed on flexible membranes in a controlled, linear-arrayed pattern. This flexible 3D printed shark skin model was then tested in water using a robotic flapping device that allowed us to either hold the models in a stationary position or move them dynamically at their self-propelled swimming speed. Compared with a smooth control model without denticles, the 3D printed shark skin showed increased swimming speed with reduced energy consumption under certain motion programs.