You don't need to watch a Spider-Man movie to notice how tough a spider web can be. Made of fiber-based spider silk, the seemingly fragile structure can hold onto insect preys and even small tree branches that are many times of its weight.
Spider silks, especially those used in the web's outer rim and spokes, have excellent extensibility, toughness, high tolerance of heat and cold. At the same weight, spider silk could be five times as strong as steel.
A team of scientists at the College of William and Mary claimed that they had unraveled the secret behind the strength of spider silk. By closely examining the structure of the silk spun out by recluse spiders, they found that it was entirely made of proteinous fibrils that are roughly 20 nanometers (nm) thick and over 1 micron (μm) long.
Previous research had pointed to fiber-based nanostrands as a part of spider silk, but the US team was the first to conclude that they make up the entire silk fiber. The unique form of recluse spider silk, which shapes like a ribbon instead of a cylinder, allowed scientists to capture its structure accurately.
Source: Science Magazine via Youtube