Innovation and Developments of Spider Silk

Last Updated on 18/01/2021

Innovation and Developments of Spider Silk

Bhavdip Paldiya
Dept. of Textile Technology
Sarvajanik College of Engineering & Technology, Surat, India
Email: bhavdipk9009@gmail.com

 

Innovation and History of Spider Silk
The method used to genetically modify the silkworm uses the PiggyBac transposon system vector discovered and developed by Dr. Fraser at the University of Notre Dame. Specific sequences of spider silk DNA are inserted into the genetic makeup of the silkworm to create a strain of the insect that now produces the spider protein. Undoubtedly innovation of spider silk is a great prospect in textile industry.

Monster silk web
Fig: Monster silk web

Strength relative to native spider silk is 80%. Silkworms are not the only species to be altered in the attempt to create a new source of spider silk.  Another firm, Nexia Biotech, created Transgenic goats. These goats produced spider silk proteins in their milk.

Introduction
Spider silk is a protein fiber produced by spiders via a unique gland. The spider silk is an extraordinary biological polymer that is linked to collagen found in human skin and bone; however, it has a much more complex structure.

The interest in spider silk has increased as further research has shown it possesses a unique combination of mechanical strength and elasticity, making it one of the toughest materials known to man.

Monster silk moth
Fig: Monster silk moth

Although the usefulness of spider silk has been known for a long time, recent breakthroughs and innovation have shed new light on the elastic properties of the silk and may lead to a new generation of ‘bio-inspired’ materials. These protein based fibers, exemplified by spider silk, have been the subject of much interest due to spider silk’s incredible toughness.

Silk Worms-Mulberry
Fig: Silk Worms-Mulberry

While the superior properties of spider silks are well known, there was no known way to produce spider silk in commercial quantities. Since spiders are cannibalistic, they cannot be raised in concentrated colonies to produce silk.

However the production of spider silk is not simple and there are inherent problems. Firstly spiders cannot be farmed like silkworms since they are cannibals and will simply eat each other if in close proximity. The silk produced is very fine so 400 spiders would be needed to produce only one square yard of cloth. The silk also hardens when exposed to air which makes it difficult to work with.

Yet the production of spider silk in commercial quantities holds the potential of a life-saving ballistic resistant material, which is lighter, thinner, more flexible, and tougher than steel.

Structure of Spider Silk
Structure of spider silk. Inside a typical fiber there are crystalline regions separated by amorphous linkages. The crystals are beta-sheets that have assembled together.

Structure of spider silk
Fig: Structure of spider silk

Characterizing Spider Silk

  1. Scientists state that spider silk fibers consist of two types of building blocks, namely, soft amorphous and strong crystalline components.
  2. The soft amorphous subunits provide the elasticity of the silk and also aid in the distribution of stress.
  3. For the silk to gain maximum toughness, a specific amount of crystalline subunits are required. It is also dependent on the way the subunits are distributed in the fiber.
Microscopic structure of spider silk cloth
Fig: Microscopic structure of spider silk cloth

Spider Silk Strength: Stronger Than Steel!

  • Kraig envisions that this genetically engineered spider silk, with its superior mechanical characteristics, will surpass the current generation of high-performance fiber.
  • We believe that spider silk is in some ways so superior to the materials currently available in the marketplace, that an expansion of demand and market opportunities will follow spider silk’s commercial introduction.
  • For example, the ability of this natural silk to absorb in excess of 100,000 joules of kinetic energy makes it the potentially ideal material for structural blast protection. The table below illustrates spider silks incredible toughness and strength yet weighing less.

Mechanical Properties of Spider Silk 

  1. The mechanical properties of spider silk will vary according to the spider species, but most displays some incredible mechanical properties.
  2. The drag-line silk is said to possess excellent mechanical properties with a unique combination of high tensile strength and ductility.
  3. The ductility of some spider silks enables the silk to be stretched up to five times their relaxed length without breaking the strand. Spider silk is also more elastic and more waterproof than silkworm silk.
  4. Quantitatively, it is reported that spider silk is five times stronger and tougher than steel of the same diameter.
  5. It is finer than the human hair, and can maintain its strength below -40°C. Furthermore, the density of the spider silk is less than cotton or nylon.

Comparison of the Properties of Natural Spider Silk, Kevlar® and Steel

MATERIAL TOUGHNESS TENSILE STRENGTH WEIGHT
DRAGLINE SPIDER SILK 120,000-160,000 1100-2900 1.18-1.36
KEVLAR® 30000-50000 2600-4100 1.44
STEEL 2000-6000 300-2000 7.84

Comparison of the Properties of Spider Silk & Kevlar®

Comparison of the Properties of Spider Silk & Kevlar
Fig: Comparison of the Properties of Spider Silk & Kevlar

Details of Laboratories Research on Silk Kraig Biocraft Laboratories:

  • Kraig Biocraft Laboratories, Inc. (Trading Symbol: KBLB) is an innovative and aggressive biotechnology company focused on the development and commercialization of spider silk. Based on proprietary genetic engineering technology,
  • The inventor of this technology, Kim Thompson, is the founder of Kraig. Kraig’s ability to produce spider silk is cost effective, and capable of producing a wide range of proteins and fibers and materials.
  • In 2013, Kraig successfully completed its pilot production program for its spider silk product, Monster Silk™, and is ramping up commercial scale production. On June 18, 2014 Kraig announced the first Monster Silk™ textile ever created in collaboration with Warwick Mills. This is a major milestone in the commercial ramp up program.
  • Kraig continues a collaborative research and development effort with The University of Notre Dame.
  • Kraig is also in the advanced development stage for its next-generation spider silk product, tentatively known as “SpiderPillar.” SpiderPillar will be an essentially pure spider silk. This material holds the potential to make significant inroads into the technical textiles market.

Market of Spider Silk:

  • Kraig is focused on the creation, production and marketing of high performance and technical fibers such a spider silk.
  • Because spider silks are stronger and tougher than steel, they could be used in a wide variety of military, industrial, and consumer applications ranging from ballistic protection to superior strength and toughness.
  • The global market demand for technical fibers is growing rapidly and they have become essential products for both industrial and consumer applications.

Applications of Spider Silk:

  1. Bullet-proof clothing
  2. Wear-resistant lightweight clothing
  3. Ropes, nets, seat belts, parachutes
  4. Rust-free panels on motor vehicles or boats
  5. Biodegradable bottles
  6. Bandages, surgical thread
  7. Artificial tendons or ligaments, supports for weak blood vessels.
  8. Other applications of spider silk include use as structural material and for any application in which light weight and high strength are required.
  9. Potential uses in the medical industry are bandages that have the ability to reduce scarring versus using traditional bandages. The silk could also be used as a scaffolding material for artificial tendon and ligament repair.

References:

  1. http://www.hindustantimes.com/world-news/soldiers-may-wear-bulletproof-spider-silk-in-the-future/article1-1235093.aspx
  2. http://www.kraiglabs.com/history/
  3. Harvesting silk from a spider-guardian
  4. Spider Silk-chm.bris
  5. Spider Silk Is 5 Times Stronger Than Steel -Naturalsciences

You may also like:

  1. Different Types of Spider Silk and Its Importance in Textile Business
  2. Kevlar Fiber: Types, Properties, Manufacturing Process and Applications

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