Spider silk

Spider silk is a protein fibre spun by spiders.

Their abdomens bear appendages that have been modified into spinnerets that extrude silk from up to six types of glands.

Spiders use their silk to make webs or other structures, which function as sticky nets to catch other animals, or as nests or cocoons to protect their offspring, or to wrap up prey. Many species of spider have different glands to produce silk with different properties for different purposes, including housing, web construction, defence, capturing and detaining prey, egg protection, and mobility (fine "gossamer" thread for ballooning, or for a strand allowing the spider to drop down as silk is extruded).

A spider web, spiderweb, spider's web, or cobweb (from the archaic word coppe, meaning "spider") is a structure created by a spider out of proteinaceous spider silk extruded from its spinnerets, generally meant to catch its prey.

Generally, orb-weaving spiders are three-clawed builders of flat webs with sticky spiral capture silk.

Spider silk is a protein fibre spun by spiders.

Many species of spider have different glands to produce silk with different properties for different purposes, including housing, web construction, defence, capturing and detaining prey, egg protection, and mobility (fine "gossamer" thread for ballooning, or for a strand allowing the spider to drop down as silk is extruded).

Ballooning, sometimes called kiting, is a process by which spiders, and some other small invertebrates, move through the air by releasing one or more gossamer threads to catch the wind, causing them to become airborne at the mercy of air currents and potentially electric currents.

In addition to using their silk for safety lines while jumping, they also build silken "pup tents", where they take shelter from bad weather and sleep at night.

Many species of spider have different glands to produce silk with different properties for different purposes, including housing, web construction, defence, capturing and detaining prey, egg protection, and mobility (fine "gossamer" thread for ballooning, or for a strand allowing the spider to drop down as silk is extruded).

A spinneret is a silk-spinning organ of a spider or the larva of an insect.

The primary structure is the amino acid sequence of its proteins (spidroin), mainly consisting of highly repetitive glycine and alanine blocks, which is why silks are often referred to as a block co-polymer.

Spidroins are the main proteins in spider silk.

Spiders use their silk to make webs or other structures, which function as sticky nets to catch other animals, or as nests or cocoons to protect their offspring, or to wrap up prey.

Synthetic silks have also been made from lyocell, a type of cellulose fiber, and are often difficult to distinguish from real silk (see spider silk for more on synthetic silks).

They exhibit a unique combination of high tensile strength and extensibility (ductility).

Females spend most of their time within their bells, darting out to catch prey animals that touch the bell or the silk threads that anchor it and occasionally surfacing to replenish the air within the web.

Peasants in the southern Carpathian Mountains used to cut up tubes built by Atypus and cover wounds with the inner lining.

This is believed to be due to antiseptic properties of spider silk (which is made of protein).

Weight for weight, silk is stronger than steel, but not as strong as Kevlar.

BioSteel was a trademark name for a high-strength fiber-based material made of the recombinant spider silk-like protein extracted from the milk of transgenic goats, made by Montreal-based company Nexia Biotechnologies, and later by the Randy Lewis lab of the University of Wyoming and Utah State University.

Throughout the process the unspun silk appears to have a nematic texture, in a similar manner to a liquid crystal, arising in part due to the extremely high protein concentration of silk dope (around 30% in terms of weight per volume).

For instance, the concentrated protein solution that is extruded by a spider to generate silk is, in fact, a liquid crystal phase.

There exist highly different specialised glands in different spiders, ranging from simply a sac with an opening at one end, to the complex, multiple-section major ampullate glands of the golden silk orb-weavers.

The golden silk orb-weaver is named for the yellow color of the spider silk used to construct these webs.

In 2011, spider silk fibres were used in the field of optics to generate very fine diffraction patterns over N-slit interferometric signals used in optical communications.

These diffraction patterns (as shown in the first photograph) are generated by inserting a spider web fiber (or spider silk thread) into the propagation path of the N-slit interferogram.

AMSilk produces a lightweight material trademarked as Biosteel, created from recombinant spider silk, which was used by Adidas to create a biodegradable running shoe.

Spider silk is a protein fibre spun by spiders.

While methods have been developed to collect silk from a spider by force, it is difficult to gather silk from many spiders in a small space, in contrast to silkworm "farms".