In today’s Academic Minute, Dr. Jason Nadler of the Georgia Institute of Technology reveals how the remora is able to maintain such a strong grip on its host.
Jason Nadler is an adjunct professor of materials science and engineering at the Georgia Institute of Technology. More specifically, Nadler is a research engineer in the Microelectronics and Nanotechnology Group at Georgia Tech Research Institute’s Electro-Optical Systems Laboratory. His principal area of interest is inorganic multifunctional porous materials systems. He holds a Ph.D. from Georgia Tech.
Dr. Jason Nadler, Georgia Tech – Recreating the Remora Grip
Common temporary attachment systems, such as suction cups, clamps or hooks, require specific surface characteristics to ensure strong durable adhesion without causing damage . Suction cups require smooth surfaces, while the reverse might be true for clamps and hooks. And none of these kinds of products can adapt to bond to other types of surfaces. In contrast, nature offers several examples of “adaptive attachment”, including geckos, tree frogs, and insects. These animals can quickly scurry up wet rocks, walls, and windows using specially evolved structures on their feet.
The remora, a fish which is commonly seen attached to sharks or whales, is particularly interesting as it has evolved a specialized fin on the top of its head that allows it to attach not only to other animals, but also to boats and buoys. The flat, oval-shaped fin or pad as it is known, looks a bit like two flattened, adjacent rows of gills.
By closely studying the remora and its complex adaptive attachment system in my lab, we have identified several different structures that make a unique contribution to the remora-host bond. For example, it has also a lip around the border of the pad that creates a seal which the entire pad to function like a suction cup. The lip’s flexibility also allows the pad to form fit to the host, and automatically becomes stiffer when something is trying to escape its grasp, like quicksand stiffens the faster one tries to escape.
Likewise, the inner surface of the pad contains several comb-like structures that increase friction between the remora and host, and improve the remora’s grip. These comb-like structures are made up of louvered sections covered with hundreds of tiny spines called “spinules” which grip like claws and help maintain suction, even when the host swims faster or changes direction.
All together these features form an “integrated system” that allows the fish to easily remain firmly attached while the host is swimming, but also remove itself by simply accelerating forward. The remora’s adaptive attachment also allows it to automatically tighten its grip if the host swims faster or changes direction without requiring any additional effort to stay attached. We’ve also found that the gripping power of the structures is not only determined by their shape, but also by the tissues of which they are comprised.
By studying the remora’s unique structures at the molecular level we’re developing a new class of biologically inspired adhesion systems to enable adaptive attachment for a vast array of human applications ranging from payload attachment for air, sea or ground vehicles, to tissue manipulation tools for delicate surgical procedures and more.