Meeting Abstract
Remoras have the remarkable ability to hitchhike on an array of host organisms by using an adhesive disc located dorsally on their head. By actively pitching rows of lamellae in the open center of the suction disc, remoras push lamellae against or away from the host’s surface, thereby tuning attachment to different hosts. We designed and fabricated an at-scale, multi-material bio-robotic remora disc (12.7 cm long and 7.2 cm wide) that contains a soft lip at the periphery, consecutive rows of lamellae with composite materials, and rigid spinules on top of the lamellae. Fluidic elastomer soft actuators were designed to control the lamellae pitching motion. We investigated the influence of the lamellae pitch angle and surface roughness on adhesive ability (quantified by chamber pressure, pull-off tenacity and frictional force) of the biomimetic remora disc in an aquatic environment. The interfacial contact mode between the lamellae and the smooth glass substrate was visualized. With very small preloads, the biomimetic robotic remora disc can attach to surfaces of different roughness, and generate considerable frictional force (>23N) and pull-off strength (>200N). We also found that by controlling the lamellae pitch angle, the lamellae soft-tissue and the rigid spinules could work together to achieve tunable, anisotropic friction while maintaining a seal on the surface. Finally, this bio-robotic remora disc was incorporated to an underwater robotic vehicle to demonstrate robust hitchhiking on different surfaces.
