Humans have been fascinated by the remarkable structure of the remora’s adhesive disc. In the case of dolphins, for example, remoras can remain attached while hosts leap out of water and spin with high rotational speeds.
The greatest advantage of this behavior is the reduced energy expenditure associated with movement: By attaching to swimming hosts, remoras can be transported over large distances with minimal effort. This hitchhiking behavior and corresponding energy savings are enabled by an adhesive disc on the remora’s cranium—a modified dorsal fin that represents one of the most extraordinary adaptations within the vertebrates.
To mimic the functions of the lamella erector and depressor muscles of the biological remora disc, they used pneumatic, fiber-reinforced soft actuators that connected with the ventral process of the biomimetic lamellae and moved linearly when pressurized pneumatically.
This adhesive technology also offers possible utility for gripping applications underwater, which requires adhesive forces in both the normal and shear directions. As demonstrated here, the attachment dynamics of our remora disc prototype thus permits high-performance underwater adhesion. Coupled with a platform of streamlined shape, such a system could markedly reduce transport and movement costs and increase mission durations for autonomous underwater vehicles.
Source: http://robotics.sciencemag.org/content/2/10/eaan8072.full