Raphael Thys
Suckerfish are the latest biomimicry models for technology inspired by nature. Also known as remoras, these hitchhiking fish travel the world’s oceans clamped to the backs of whales, rays and sharks, among other sea creatures.
In a recent paper in the Journal of Experimental Biology, researchers explained how they used a webcam to hitchhike alongside a blue whale. The footage showed that suckerfish cruise with ease, using fluid dynamics to stay attached. This finding and further exploration of the suckerfish sucker anatomy has inspired new technology that could help with attaching sensors and other gear to rough surfaces.
Blue Whale Cam Photobomb Shows Suckerfish Action
The authors of the blue whale research project said that, in addition to following the marine giants as they cruised the world oceans, the monitors also caught plenty of suckerfish activity. This comment inspired suckerfish researcher Brooke Flammang to take a closer look.
CBC Radio’s Quirks & Quarks reports what Flammang saw in the footage — that instead of being tightly attached, the suckerfish could skim across the whale’s body by staying close to its surface. Instead of clamping to the whale’s skin, the sucker hovered slightly above the skin, forming a low-pressure zone that sucks the fish in close. Even at full speed on the whales, the remoras were quite mobile and still stuck around for the ride.
Suckerfish Ride Dynamics Inspire New Technology
With a keen interest in bio-inspired robotics and comparative biomechanics, Flammang’s lab was able to create mathematical models to mimic the suckerfish’s apparently effortless ride. In the Journal of Experimental Biology paper, Flammang’s team describes how they created a 3D, mathematical model of the blue whale surface. Using computational fluid dynamics analysis, they found that the remoras were skimming around in a boundary layer cushion of slow-moving water next to the whale skin.
Apparently, the suckerfish were using physics to find the best places to hitch a ride, using the least effort to stay close to the whale and then benefiting from the Venturi effect – the reduction in fluid pressure that results when a fluid flows through a constricted space, like a section of a pipe – to move around. As the researchers note, having this knowledge could help marine biologists place biosensors that stay attached for longer than 24 hours.
Sucker Anatomy Informs Adhesive Sensor Design
In addition to helping conservationists place sensors and track blue whales and other marine mammals more effectively, suckerfish may also hold other clues for technology inspired by nature. A 2020 paper shows what contributes to suckerfish adhesive tenacity.
In the journal Matter, scientists published the first report describing the anatomy of the remora’s sucker disk in detail. They found that the lip is key to successful attachment on rough surfaces, such as whale and shark skin. Vertically aligned collagen fibers in the layers underneath the rim give the edge of the suction cup enough elasticity to maximize contact with rough surfaces. When the researchers created a biomimetic sucker based on their findings, the new technology showed 62.5% better adhesion.
Biomimicry Continues to Drive Innovation
Biomimicry, or technology inspired by nature, is a growing area of science and engineering. Instead of developing man-made solutions to problems, engineers look at systems within nature that have already solved the problem in question.
For example, think about Velcro. This technology was inspired by the way certain plant seeds stick tightly to clothing. New technology inspired by nature has also delivered uncrushable design and enhanced sensor capabilities inspired by beetles and bird flight.
Inspired by the whale-surfing remoras, Flammang and her lab are developing biomimetic suckers that can cope with rough surfaces. Smithsonian Magazine notes that the bioengineers have created a sucker device based on remora anatomical features that shows 60% greater adhesion, especially on rough skin. Maybe suckerfish hold the clue to tracking larger marine creatures through the world’s oceans.
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