“You can’t modify real shark skin,” explains George Lauder from Harvard University, one of the authors of the study, published Wednesday in the Journal of Experimental Biology. Lauder found a piece of mako shark at a local fish market, and scanned the skin to create a high-resolution view of the surface. Next, he and his team zoomed in on a single denticle to build a detailed model of its structure, and then reproduced it thousands of times in a computer model.
But they needed to build a real model. To do that, they constructed a realistic artificial skin using a 3-D printer, which allowed them to embed hard denticles in a flexible substrate—after some trial and error.
“The denticles are embedded into the membrane and overlap, which posed a key challenge for 3-D printing,” Lauder says. Finally, after a year of testing different materials, sizing and spacing, the team produced a convincing fascimile.
“Seeing the SEM [scanning electron micrograph] of the curved membrane with the denticles was a great moment for us,” Lauder says."