Manufacturing artificial spider silk: many useful applications in the future

A group of engineers from the Massachusetts Institute of Technology (MIT) has identified two key physical processes, resulting from studying the strength and durability of the spider silk's champion, to proceed to realize. a goal that requires long-term effort is: weaving artificial spider silk.

MIT scientists hope that the golden silk spider will help them learn how to produce strong and durable artificial silk.(Photo: Nikola Kojic)

Artificial spider silk can be used to create artificial ligaments and tendons, used to sew wounds after surgery, though used to land from above and used in bulletproof vests. However, engineers just haven't done it easily the jobs the spiders do.

In a study published in the November issue of Experimental Biology, mechanical engineering professor Gareth H. McKinley and colleagues studied how spiders weave their threads in hopes. that it will replicate artificially this way at a basic level.

Professor McKinley is leading the research team of ' Non-Newtonian Fluid Dynamics ' at MIT. (One of the important properties of fluids is the internal friction between moving currents. This friction force is often called the viscosity. When the viscosity depends on the force that causes the slip between the currents. We call that flow ' non-Newton '. If the viscosity depends only on the difference in velocity between the currents, then we call it ' Newton ' flow. ' Non-Newtonian liquids react in very strange and unexpected ways because they have viscosity or slippage and have a resistance to stretching of very strong liquid elements.

Spider silk is a protein solution markedly altered in the process of being woven into silk. Egg whites, another non-Newtonian liquid, change from a water-based gel to a rubber-like solid when heated. Spider silk, discovered, is also subject to physical changes that cannot return to its original form, like egg white.

Stickiness and viscosity of spider silk

Professor McKinley and a graduate student Nikola Kojic of Harvard University, MIT Faculty of Technology and Health Sciences, studied the silk of spider Nephila clavipes, a golden silk spider weave that could weave a net The spider is so strong that it can catch small birds. In the South Pacific, people make fishing nets from silk of this kind of spider web.

(Photo: bodoc.net)

Scientists choose golden silk spider because its spider web has a very ' tough ' durability . But Mr. Kojic was startled when he saw the first palm-sized spider crawling out of the box he received from the mailbox from a very enthusiastic employee of Miami's MetroZoo Zoo. (The employee earned these golden silk spiders from the garden because the zoo did not raise these spiders.)

He said: ' It is quite scary. I've never seen a big spider like this. I have never lived in the middle of anything that has such hairy legs . ' But then, he quickly regained his composure and began to operate the protruding shape and size of pea on the backs of these spiders, which contained the silk-producing routes and the spinnerets of spider.

The spiders do not actually spin silk (' spinning silk ' is an ancient form of art, pulling and spinning cotton threads together to form only); instead, they spew out a thick gel containing silk solution. (A teaspoon of gel can make 10,000 spider webs.) They then use hind legs as well as body weight and gravity to extend the gel into thin threads.

Kojic absorbs an extremely small amount of gel-like solution from the spider's main gland in the abdomen.

Scientists then used devices called tiny accelerometers to study the silk droplets - to check the properties of this material when impacted. The team examined the viscosity of the spider silk solution by " cutting " it or placing it between two moving pieces of glass at high speed and checking the adhesion of the spider silk solution by separating it into small fibers between two metal plates, like how to make taffy.

And the researchers discovered the miracle of making spider silk strong and durable. The miracle that occurs when the silk is sprayed out of the spider's silk gland, lengthens into a small thread and dries.

The secret for artificial spider silk

The secret to creating spider silk is Polymer.

Polymer (Photo: greenfacts.org)

Plastic plastic, Kevlar (used in bulletproof vests) and some parts of the International Space Station are some of the objects made from polymer. Protein in our bodies is made up of amino acids. Polymer in Greek means ' many ' and ' unit ', they are long chains of small molecules joined together. They can be flexible or hard, soluble in water or insoluble, resistant to heat, chemicals and very durable.

Silk protein solution contains 30 to 40% polymer; the rest is water. The spider's silk-producing gland is capable of synthesizing large-grain proteins and ' processing' those proteins into insoluble silk fibers.

The long strands of spider protein are like twisted spaghetti . They form a flexible and sticky solution but are slippery enough that the molecules can slide over each other and twist, through the gland on the abdomen. When the gel contains a silk solution sprayed from this gland through a spiked, S-shaped tube and out of the spider's body, the long chain of protein molecules becomes straight and into viscous droplets with a viscosity of equal or more than 500 cSt.

Because the resulting liquid sprayed off the spider's abdomen through the spinneret, it has the properties of liquid crystals. It is a clever combination of protein fibers, which helps silk fibers have a surprising durability.

While the silk relaxes and dries, it forms crystal structures that increase the strength of the fibers. Therefore, it is possible that materials made from small nanoparticles will meet the same way.

Along with polymer synthesis and analysis work done by MIT Institute Professor of Chemistry Paula T. Hammond, Professor McKinley's lab will use the new knowledge of spider silk to join with Study Institute in the Soldier Nanotechnologies program to create silk-like spider silk through polymer fabrication process.

Professor McKinley said, ' We are very interested in artificial materials that have spider-like properties. The fabrication of the properties of liquid synthetic silk materials similar to the properties of real spider silk, can be extremely important in helping us to successfully create new synthetic materials. strange with similar mechanical properties even better than the mechanical properties of natural spider silk '.

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