Here’s How a Spider Makes Silk 10 Times Tougher Than Kevlar

The post Here’s How a Spider Makes Silk 10 Times Tougher Than Kevlar appeared first on A-Z Animals .

Spider silk is one of the strongest materials in nature. Because of this, silk has been used in battle to protect warriors and soldiers from injuries. But could spider silk stop a bullet? Darwin’s bark spider silk may just be able to.

Darwin’s Bark Spider Silk Is the Strongest Biological Material on Earth

Spider webs, in general, are strong thanks to the proteins from which the silk is made. These proteins, called spidroins , make the webs both strong and flexible. However, when it comes to the strength of spider silk, Darwin’s bark spider is in a class of its own. This is because the silk is three times stronger than iron and 10 times stronger than Kevlar . Additionally, the silk can stretch up to 90% of its original size before breaking.

Only the females of the species are capable of creating webs of this strength. Females are significantly larger than males , at 0.7 to 0.9 inches, compared to 0.2 inches, and are nearly two times heavier. Compared to other orb spiders, or spiders in general, female Darwin’s bark spiders are not exceptionally large. This makes the strength and elasticity of their silk that much more impressive.

Why Is Darwin’s Bark Spider Silk So Strong?

Darwin’s bark spider is found in Madagascar. These spiders spin their webs above bodies of water, most often rivers, which require them to move from one bank to the other without falling. They do this because of the abundance of prey captured in webs . Therefore, the strength of the silk is key to their survival.

Living above bodies of water can be precarious for spiders. One false move and they could easily drown. In environments like those where Darwin’s bark spider lives, which can be windy and have rushing rivers, their spider silk needs to be not only strong but also flexible.

According to a 2021 study , it is not uncommon for the webs Darwin’s bark spiders weave to be over 80 feet across. The anchoring parts of the webs are on each side of the river. Given the strength of the webs, the larger prey the spiders feed on cannot break the web and are instead stuck.

Can Darwin’s Bark Spider Silk Stop a Bullet?

There is no question as to how strong Darwin’s bark spider’s silk is. Given its strength, can it stop a bullet? With current technology, the answer is no. However, this could change in the future.

The fact is, the silk is too thin to stop a modern bullet in motion. The kinetic energy of a bullet is between 600 feet and 4,000 feet per second . Without the assistance of bioengineering, even layering the silk would not stop a bullet. With that said, silk was used in battle by Mongol soldiers , Americans in WWI wore silk scarves to protect against shrapnel , and even bulletproof vests at the turn of the 20th century could slow bullets or prevent shrapnel from causing harm. In these instances, the bullets were low-velocity, and the shrapnel was smaller in size. When high-velocity bullets were used, the silk proved to be ineffective.

Currently, bioengineers are working to create lighter-weight body armor for the military . While research is still in the early stages, it is possible that Darwin’s bark spider silk could one day be used to create the safest body armor yet, protecting wearers under fire.

How Much Silk Would It Take to Stop Large Objects in Motion

To put into perspective just how much Darwin’s bark spider silk it would take to stop large objects in motion, the thickness of the silk needs to be considered. One strand is incredibly strong, but not strong enough to stop a bullet. But if the thickness of the silk were increased, larger objects could be stopped in their tracks.

With the strength that is 10 times that of Kevlar and the capacity to stretch up to 90% of its original size, all it would take for Darwin’s bark spider silk to stop a 747 mid-flight is for it to be the width of a pencil . Some estimates put the width even smaller. Therefore, to stop a slow-moving car or even a charging bear, the required thickness of the silk strand would be significantly less.

Although technology is not yet advanced enough to use Darwin’s bark spider silk in body armor that can stop bullets or massive objects, it is likely that silk will be used for such purposes in the future. Therefore, it may only be a matter of time before soldiers are better protected, all thanks to a small spider and its unrivaled silk strength.

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