May 5, 2015
Clingfish may hold future to suction tech
By studying a species known as the Northern clingfish, researchers from the University of Washington (UW) hope to develop new devices and instruments that could be used in surgery, for tagging and tracking whales in the ocean, and other purposes.Petra Ditsche from UW’s Friday Harbor Laboratories on San Juan Island and her colleagues are studying the Northern clingfish, a finger-sized creature found in the waters off the coast of Puget Sound that is said to be one of nature’s best suction cups – it uses suction forces to hold as much as 150 times its own body weight.
Northern clingfish actually stick better to rough surfaces than smooth ones, outperforming even the most powerful industrial suction devices on uneven structures. By analyzing the creature, the UW team hopes to learn how it is able to generate such suction in wet conditions.
Ditsche, who presented her team’s findings last month at the spring convention of the Adhesive and Sealant Council in Nashville, said that the clingfish’s strong suction capabilities are “very desirable for technical applications,” and that the creature could “provide an excellent model for strongly and reversibly attaching to rough, fouled surfaces in wet environments.”
Unique properties could lead to new medical devices, whale tags
She explained that northern clingfish have a disc on their bellies that is covered with layers of tiny hairlike structures, and that this disc is the key to their ability to hold fast to different types of surfaces. The layered effect of these structures allowed the fish to stick to rough surfaces, and the elastic properties of the disc allows it to adapt on rougher areas.
Clingfish are far from the only creatures capable of sticking to underwater surfaces (mussels, sea stars and anemones are among the others), but few others can release their grip as quickly as the clingfish. Due to their ability to hold with great force on wet, coarse and often slimy surfaces, the researchers believe that they could serve as the inspiration for new biomedical devices.
“The ability to retract delicate tissues without clamping them is desirable in the field of laparoscopic surgery,” said Adam Summers, who heads up the research team that includes Ditsche. “A clingfish-based suction cup could lead to a new way to manipulate organs in the gut cavity without risking puncture.”
Likewise, the research could lead to the development of a new tagging tool for whales that would let scientists use noninvasive tags that stick to the body of the creatures rather than having to puncture their skin with a dart (the method typically used for long-term tagging studies). Ditsche, Summers and their colleagues also plan to study how long clingfish can remain fixed to a surface and why larger ones appear to be able to stick better than smaller ones.