Micro-Actuators for Kinematic Optimization (MAKO): Manufacturing Shark Skin Inspired Surfaces for Separation Control*

Perhaps the biggest challenge facing any new flow control technology is designing a practical system. Shortfin mako shark skin has a passive dynamic microgeometry which serves to impede reversing flow and add momentum to the boundary layer. These effects result in augmented resistance to flow separation as demonstrated in water tunnel experiments. Engineering such a surface could be useful for aerodynamic applications. Additive manufacturing has been employed to manufacture surfaces that can capture the miniscule size, detailed structure, and passive actuation ability of mako skin. Several prototypes have been developed and tested. Wind tunnel tests of early prototypes have demonstrated scale actuation by flow in the lower 5% of the boundary layer. Revised prototypes are in development, addressing issues in the manufacturing tolerances of previous designs. A novel concept utilizing a flexible silicone base is also proposed and investigated.