One Glue, Two Functions

Posted on 10/10/2012 9:14:38 AM By ASC

Scientist at the University of Akron are spending a lot of time considering spiders. And they have very good reason for focusing on their eight-legged subjects. Common spiders are able to use the same glue to produce two different adhesive profiles in the adhesive discs that anchor their webs. Hanging webbing, meant to catch flying prey, has a strongly-bonding adhesive disc that can support the weight of prey caught in the webbing. Conversely webbing at the ground, meant to catch walking prey, has a weekly adhesive disc. When something walks into the web and becomes entangled, the adhesive disc comes loose to leave the captured prey dangling from a silk thread. The difference between the strong and weak discs is not chemical – the adhesives are the same compound, produced by the same glands on the spider. Instead, the adhesion differences are produced by different structures created by the spider’s spinning behavior. Biologists and polymer scientists are hoping to use that concept to develop synthetic adhesives with variable strengths.  If they are successful, the resultant adhesives would be particularly useful for biomedical applications.