Snails secrete a mucus that acts like superglue, allowing them to adhere to rough surfaces like rocks.
Inspired by this aspect of snail biology, scientists at the University of Pennsylvania, Lehigh University and the Korea Institute of Science and Technology have created a superglue-like material that is “intrinsically reversible.” In other words, it can easily come unglued.
Adhesives are everywhere―in daily life and in industrial applications. But achieving both strong adhesion and reversibility (or the ability to reverse the adhesion) is challenging. According to Anand Jagota, professor and founding chair of the Lehigh's Department of Bioengineering and professor of chemical and biomolecular engineering, this is especially true of hydrogels, which are 90% water.
He says that adhesives usually fall into one of two classes: strong but irreversible, like superglues; or reversible and reusable but weak.
The team has managed to overcome these limitations. They have reported their findings in a paper, published today in Proceedings of the National Academy of Sciences, titled “Intrinsically reversible superglues via shape adaptation inspired by snail epiphragm.”
“We report a hydrogel-based, reversible, superglue-like adhesive by combining the benefits of both liquid and dry adhesives in a single material,” says Jagota, who is also affiliated with Lehigh's Institute for Functional Materials and Devices (I-FMD) and Institute for Institute for Data, Intelligent Systems, and Computation (I-DISC).
The team reports that when hydrated, the softened gel they created conformally adapts to the target surface by low-energy deformation, which is then locked upon drying in a manner similar to the action of the “epiphragm” of snails. An epiphragm is a temporary structure created by snails and mollusks. Made of dried mucus, it holds in moisture during periods of inactivity and enables snails to adhere to surfaces, like a rock.
Read the full story in the Lehigh University News Center.
Story by Lori Friedman