Most people know that a spider’s life depends on its ability to catch unsuspecting prey in the sticky tendrils of its silken web, but have you ever wondered exactly where this adhesive quality comes from?
A couple of materials scientists at the University of Akron in Ohio wondered the same thing, so they’ve conducted experiments to “figure out the properties of the microscopic substance that orb-weaving spiders deposit along the round rings of silk they spin as part of their webs” (PhysOrg).
Spider webs come in all shapes and sizes, but up until recently, scientists had only small understanding of why and how they help the arachnid get a good meal. Spiders’ silk is created by two stomach glands that secrete proteins, and has been found to be stronger than steel, by weight.
Ali Dhinojwala, a professor and chair of the department of polymer science at the University of Akron in Ohio, and Vasav Sahni, a doctoral candidate, joined forces with Todd Blackledge, a professor of biology, to develop a better idea of what this mysterious sticky substance actually is and why it is so sticky.
What they found is that the substance, which is made up of highly entangled polymers, is both viscous and elastic, both of which are “valuable properties for catching fast-flying, incoming insects–and in keeping the victims trapped long enough for the spider to subdue, and devour, them” (PhysOrg).
Dhinojwala compared the substance to chewing gum because it continues to stretch long after the anticipated breaking point.
Another unique property of the polymers is that they don’t lose their stickiness when moisture is introduced. In fact, moisture is necessary to maintain the elasticity of the web- without it, the tines could be destroyed by a struggling morsel.
“What the spider does is evolution at its finest,” Dhinojwala told PhysOrg. “They have survived by using nature effectively. The more we learn of how nature uses these materials, the better position we will be in to take advantage of this and design things based on what we learn.”
Image Credit: Flickr - photofarmer