To improve a flying vehicle, sometimes you have to turn to a reliable model that has been operating for hundreds of millions of years.
A team of evolutionary biologists and engineers at Harvard University, along with researchers from the University of South Carolina, are using shark scales to design better drones and planes.
The distinct grooves of shark skin scales provide a valuable model for vortex generators – small aircraft aerodynamic devices that disturb and change the flow over a given surface, reducing drag and increasing lift.
George Lauder, co-author of the research and Professor of Ichthyology and Biology at Harvard University, spoke with Tech Briefs about his (bio)inspirations.
Tech Briefs: What are the unique characteristics of sharkskin that enable better aerodynamic performance?
Lauder: Shark skin scales, or denticles, have a unique surface pattern with small grooved depressions and ridges. Individual denticles overlap in a pattern on the skin, but it is still not clear what effect the broader surface patterning has. We have shown that denticles (through still unknown specific hydrodynamic mechanisms) function to both reduce drag and enhance lift on surfaces that they are applied to.
Tech Briefs: What made you think of the shark as a starting point for design?
Lauder: Evolution has operated on the skin of sharks for over 450 million years to arrive at structures that improve swimming performance. So, it is natural to use shark scales as inspiration for improving the performance of all types of swimming and flying vehicles.
Tech Briefs: What were the specific shark-inspired parts that you designed and made?
Lauder: Using 3D printing, we made a wing, or airfoil, with attached small shark skin scales in various patterns. We tested 20 different configurations to determine the effect of the shark scales on flow over the wing, and on lift and drag forces. We showed that the scales can both reduce drag and also enhance lift.
Tech Briefs: What’s next?
Lauder: We are now exploring the diversity of different types of shark scale structures by looking at many species and getting a better sense of the diversity of scale types and skin patterns in nature. We then plan to study how these different scale types and patterns affect swimming and flying performance.
What do you think this bio-inspired design could enable? Share your thoughts below.