New adhesive surface modeled on a remora works underwater

Conventional adhesives struggle to bond with wet surfaces due to the interference of water and other liquids. However, a fascinating solution has emerged from the evolutionary design of the remora suckerfish. These remarkable fish utilize an adhesive disk situated atop their heads, allowing them to securely attach to various marine creatures, such as dolphins, sharks, and manta rays. Researchers at MIT have embarked on a detailed study of these unique remora disks, successfully reverse-engineering their structure. Giovanni Traverso, a professor at MIT's Department of Mechanical Engineering and a lead author of the research, emphasized the significance of nature as a source of inspiration for innovation. The remora's adhesive disk is an evolutionary modification of what is known as the first dorsal fin, which in other fish species is typically positioned behind the head and gill covers. This disk is supported by a specialized backbone, likely derived from spinal components. It features lamellae—bony plates adorned with tiny, backward-facing spikes known as spinules. These adaptations enable the remora to adhere effectively to the soft, agile bodies of its marine hosts. According to Traverso, the adhesion process involves the remora pressing against the host's skin, which expels the water from the disk's tissue compartments, resulting in a low-pressure environment. The spinules then engage mechanically with the host's surface, functioning similarly to a combination of a suction cup and Velcro. When the remora wishes to detach, it simply lifts the disk, allowing water to flow back into the compartments and releasing the suction, enabling it to swim away effortlessly.