Mark Megahan
With the crisp of autumn in the air, spider webs are a necessary part of the Halloween decorations. Meanwhile, there are a whole bunch of researchers dedicated to unlocking a secret spiders have mastered. It turns out that spider’s silk happens to be one of the strongest substances in the world, pound-for-pound.
Spider silk beats steel
Just because your great-grandmother kept spider webs in a jar as a household necessity doesn’t mean she was a witch. For time out of mind, until Johnson & Johnson unleashed Band-Aids onto the scene, they’ve been used to dress cuts, especially ones which won’t stop bleeding.
Folk healers knew that the silk of spiders has interesting properties and modern engineers desperately want to learn their secrets.
“Numerous scientists aspire to unlock the remarkable capability of spiders to spin silk threads that are immensely strong, lightweight, and flexible. In fact, pound for pound, spider silk is stronger than steel and tougher than Kevlar.”
Whoever figures out how to synthesize it in the lab will make a fortune. “However, no one has been able to replicate the spiders’ work yet.”
A “whole new world of possibilities may open,” the pundits claim. “Artificial spider silk could replace materials like Kevlar, polyester, and carbon fiber in industries and be used, for example, to make lightweight and flexible bulletproof vests.”
Bridges can be longer and carry more traffic. The options are nearly endless.
Race for super silk
Postdoc and biophysicist Irina Iachina isn’t afraid of spiders. Her Department of Biochemistry and Molecular Biology at the University of Southern Denmark is particularly interested in the orb-web spider Nephila Madagascariensis. The lab is virtually covered in them. She’s one of the front runners in the “race to uncover the recipe for super silk.” She’s been at it for years “since her time as a master’s student at SDU.”
Right now, she’s hanging out “at the Massachusetts Institute of Technology in Boston with support from the Villum Foundation.” There, she teamed up with professor and biophysicist Jonathan Brewer at SDU, “who is an expert in using various types of microscopes to peer into biological structures.”
Together, they mapped out the internal structure of the silk spun by their favorite species of spider. The important part is that by using several different imaging techniques they were able to get results without cutting or tearing the material, thereby distorting it’s coherence.
“We have used several advanced microscopy techniques, and we have also developed a new kind of optical microscope that allows us to look all the way into a piece of fiber and see what’s inside,” Brewer explains.
What they learned are that there is a bundle of fibers running parallel to each other as a core. It’s important to know that they aren’t “twisted.” That’s something nobody was sure about. Around that is a DNA sheath like the insulation on electrical wires and cables. A second outer coating encircles that. The spider silk also comes in two types, both produced by the creature at will.
One a heavy duty “life-line” cord, which can handle incredible weight by comparison to it’s size, and a much lighter duty string, used for most of the spider’s construction needs. The next step is cooking some up in the lab. “Right now, I am doing computer simulations of how proteins transform into silk. The goal is, of course, to learn how to produce artificial spider silk, but I am also interested in contributing to a greater understanding of the world around us,” Irina Iachina relates.
