Is Spider Silk Stronger Than Steel?
Did you know that if a spider web was human-sized, it would be strong enough to hold up a person and then some? Spider silk begins as a liquid form called dope. But in the blink of an eye, this liquid transforms into something much more powerful.
This is because as the dope is released, the spidroins, spider silk's very large proteins, fold themselves and interlace, leading to a complex and sturdy structure. During this spinning process, the spidroins separate themselves from the watery buffer that holds them inside the silk glands.
An influx of acid then prompts the proteins to securely interlock. Webs are essentially made up of nanostrands. Scientists used an atomic force microscope to discover these nanostrands that are 1000 times thinner than a human hair.
The main chemical components of spider silk are glycine, alanine, and a small amount of serine. This makes it extremely powerful. Spider silk has a tensile strength of about five times that of steel. It has a higher strength-to-density ratio and a similar tensile strength to the metal.
It has been suggested that a Boeing 747 could be stopped mid-flight by a single pencil-width strand of spider silk. It doesn't just beat steel; it also has an advantage over the toughest man-made polymer, Kevlar.
The Ancient Greeks knew about spider silk's many applications over a thousand years ago. They would use it to stop bleeding and heal wounds. The material even found its way into World War II as a crosshair for sighting systems of telescopes and guns.
Spider silk works wonders in most temperatures, effectively maintaining its main properties even in extreme heat and cold. It holds up against 392°F (200°C), even coping well beyond 572°F (300°C). On the other hand, when the temperature drops, spider silk doesn't suffer.
It will retain its elasticity down to minus 40°F (40°C) before succumbing to the harsh conditions. Nowadays, there is a lot of research into using spider silk within the medical industry. Surgeons use spider silk proteins to keep wounds clean during the healing process.
Meanwhile, wearables made from spider silk are lightweight, breathe better, and have UV resistance. As research continues on spider silk, this material is bound to be found in multiple industries. Its ability to biodegrade, in particular, make it a good candidate for many future applications. Can you think of a significant case use for spider silk?