That's right, the this blog title says it all. When people think of snails they tend to picture the slimy, bug-like mollusk that stick to a trees or other wall-like structures leaving behind trails of epiphragm or more commonly know as snail slime. Perhaps even a few people picture a searing plate of escargot. We'll save that conversation for another day!
When presented for the need of a self healing, reversible adhesive professor Shu Yang, along with post doctoral research associate Hyesung Cho and a pair of Penn State engineering graduate students, decided to bring nature to the lab environment.
Professor Yang's team started with studying Geckos as their original inspiration. The problem with the clingy lizards is that though their adhesion is reversible, the strength to weight ratios is very weak. The breakthrough for the epiphragm-like substance came about when Gaoxiang Wu, one of the Penn State engineering graduate students was working on another project that involved a hydrogel called polyhydroxyethylmethacrylate (PHEMA) and noticed its remarkable adhesive properties.
PHEMA is rubbery when wet but rigid when dry, a quality that as Yang's team discovered, is very useful for adhesives. When the PHEMA material is is exposed to moisture it conforms to surface cavities, completely covering the entire surface area it's applied to. When the material dries, it becomes extremely rigid, but unlike other adhesive solutions, the PHEMA does't shrink. Instead the PHEMA hardens continuing to remain in all crevices and fastening itself to the surface.
"When materials dry, they usually shrink. If it shrinks from the surface, it no longer wants to conform to the microcavities and it'll pop out," says Yang. "Our PHEMA adhesive doesn't pop out. It stays conformal. It remembers the shape even when it's dry and rigid."
These unique properties helped Yang's team identify PHEMA as a perfect candidate for reversible, strong adhesion and are the same properties found in a snail's epiphragm. A snail's slimy epiphragm, when wet, integrates to the surface it's on and hardens, protecting the snail from the dry environment and firmly holding the snail in place. When the snail's environment becomes moist again, the epiphragm softens, allowing the snail to move freely again.
At Chemique Adhesives, we're aren't going to sell you any snail slime. However, we do provide a full range of premium bonding and sealing solutions used across many industries including: Transportation, Modular Construction, Construction, Commercial Manufacturing, Composites, and Foam Conversion. Our team of adhesive experts will listen to your needs, and develop a tailor-made plan that works best for your production environment and manufacturing goals. Contact Us today to speak with one of our adhesive experts, or to schedule a no strings attached product demonstration.
To lean more about PHEMA, and Professor Shu Yang's research team read the full article in Science Daily by Clicking Here or visiting this link: https://www.sciencedaily.com/releases/2019/06/190617164703.htm