Published January 12, 2012
After decades of trying, scientists may have finally found a way to make body armor out of spider silk.
Aside from being very cool, this would mean ultra-lightweight, super-strong, flexible body armor that would provide highly improved protection for America’s soldiers and law enforcement officers.
Right now, U.S. soldiers must wear very heavy, inflexible and cumbersome body armor for protection. Typically it is hard body armor, a ballistic vest with at least two large, hard ceramic plates, designed to protect the upper body from shrapnel and bullets.
Hard armor basically works by resisting the force of the bullet or shrapnel with the same degree of force. But the more protection hard armor provides, the heavier and more ungainly it becomes. The lowest level protects only against small-caliber projectiles that have less force on impact. Hard-armor design often involves the ability to scale up protection, so there are pockets into which additional plates can be inserted.
While protection is important -- reports indicate that the risk of death from gunshot is 14 times higher for law enforcement officers who don’t wear armor -- users often find themselves weighing the risk of being shot with the reduction in speed, mobility and agility that hard armor’s weight and unwieldiness can cause.
While soldiers wear hard armor on a daily basis, law enforcement officers in reduced risk situations often prefer the flexibility and lighter weight of soft body armor, which works by spreading out the blunt trauma so that the force is not received in one focused spot. Soft armor often slows down bullet or shrapnel through layers or interwoven fabrics that act like nets or spider webs.
Developing lightweight, flexible soft body armor with the higher degree of protection of hard body armor has so far been the impossible dream.
DuPont’s Kevlar fiber, the soft armor fiber widely adopted by law enforcement, is often described as five times stronger than steel -- but spider silk continues to outperform its artificial counterparts, so the pursuit of Spider-Man style armor has been underway for decades.
Strand-for-strand, researchers in the field know, the dragline of an orb-weaving spider, while weighing far less, can be three times more flexible than Kevlar and five times stronger than steel.
Contrary to its size and weight, spider silk is naturally capable of absorbing a huge amount of energy.
Last year, a team at the Heidelberg Institute For Theoretical Studies in Germany studied the building blocks to the mystery behind what makes spider silk so naturally strong.
There are two key components to spider silk fiber: the soft goo gel that is manufactured in the abdomen and the strong solid thread that it has become when it leaves the body.
This team’s findings, published in Biophysical Journal, suggest that the same components that give the soft goo silk elasticity lead to the stress distribution handy for body armor.
While capitalizing on the natural attributes of spider dragline seems like a no-brainer, the coveted prize of creating spider silk body armor has not been without serious obstacles.
Among the chalenges: cracking the genome profile of ideal spider silk; finding a way to synthesize the silk-making protein; and devising a method to mass-manufacture the protein in the volumes necessary.
For a long time, the focus has been on the silk of one of the world’s most lethal spiders -- the black widow, the dragline of which could provide material stronger than Kevlar or steel, and in a far lighter weight and more flexible way.
But farming the spiders has not been an option, as spiders tend not to play nicely with each other – they tend to turn into a fight club and fail to produce the mass volumes necessary.
In 2007, scientists at the University of California announced they had identified the black widow silk genes, and they tried injecting it into tomato plants, with the objective that the tomato seed would provide the spider silk.
Tomato plants, crops, bacteria, yeast -- even goats -- have gone in and out of fashion as vehicles for converting the spider silk gel into solid thread.
Enter silkworms. They produce fragile silk, but they have heaps of natural potential as high volume producers capable of spinning approximately a kilometer of silk thread in a few days, with a long history of successful human cultivation.
In Thailand in 1999, the Rajamangala Institute of Technology reported that it had developed body armor using only standard, low-cost silkworm silk. Tests indicated that 16 silk layers could stop a 9mm bullet, and that the vests could provide protection against high-velocity rifle shots as well as .22 caliber handguns.
More recently, silk has even been successfully exploited for “blast boxers.”
The latest breakthrough was achieved by the University of Wyoming and published in Proceedings of the National Academy of Sciences this month.
According to their publication, they have succeeded in genetically modifying silkworms to produce a combination of worm and spider silk that is as strong as spider silk.
Arguably, the Holy Grail for Spidey body armor would be cracking the bark spider, reputedly 10 times stronger than Kevlar, and then applying these new silkworm factories.
Bark spider silk is the strongest on earth, 100 percent tougher than all other documented silk.
Discovered last year in Madagascar, the bark spider not only makes the largest orb web at up to 25 meters, it has the strongest dragline silk in the world and the elasticity to absorb three times more energy than Kevlar before breaking.
From parachutes, airbags and sportswear to biodegradable fishing ropes, lines and nets, the range of potential civilian applications is diverse.
Advances applying spider silk to the medical field have already been made, and research continues into sutures, wound coverage, stronger artificial tendons and ligaments, assisting joints to heal by harnessing the resilience of silk and to help nerve repair and regrowth.
Transforming body armor for soldiers and cops by providing far superior ultra-lightweight protection is a long overdue revolution. Let’s hope the bark spider dragline gets silkwormed and body armored up stat.
Ballet dancer turned defense specialist Allison Barrie has traveled around the world covering the military, terrorism, weapons advancements and life on the front line. You can reach her at firstname.lastname@example.org or follow her on Twitter @Allison_Barrie.