Clever design: The key to a spider web's success is 'sacrificial beams' which allow just one, or a few, threads to break while keeping the rest intactTougher than steel and intricately woven, spiders’ webs are certainly a natural wonder. Now a team of scientists has worked out why they are resilient enough to withstand the force of hurricanes and fierce attacks from predators.
It is not just the remarkable strength of the silk, but its clever design.
The key to a web’s success is its ability to remain intact and even stronger after threads break, say researchers at Massachusetts Institute of Technology.
They say the findings could be used to help design fail-safe buildings and even a new generation of unbreakable materials.
A typical web uses up a huge amount of a spider’s energy – so it contains a series of features which stop major repairs being needed.
The researchers found the silk itself has an ability to soften or stiffen to withstand different types of loads put on it – unlike any other natural or manmade fibres. In tests against three other materials made into similar webs, the spider silk was six times more resilient to damage when subjected to falling twigs or high winds. When a weight was applied, only one thread broke – so the spider could do minor repairs rather than start from scratch.
The researchers found that it wasn't the strength of the fibres that gave webs their elasticity - it was the designRemoving up to 10 per cent of the threads from various areas made the web not weaker but actually up to 10 per cent stronger.
Report co-author Markus Buehler said: ‘The real strength of the web is not the silk but how its mechanical properties change as things strain it, which is a very sleek inbuilt feature which could be used in many areas of life to contain damage to a small area.’
Scientists have already shown how spider silk is five times as strong as the same weight of steel.
Wasp spider, Argiope bruennichi, in web, ItalyThis study, published in science journal Nature, looked at every aspect of the web. They contain two types of silk, a stiff, dry one for the threads which come out from the centre and hold it all together.
Then there is a thinner, stickier one called ‘viscid silk’ for the spiral threads which are mainly used to trap prey.
The authors found both types are constructed to ‘localise failure’ so only one thread breaks.
Thinking ahead: A typical garden spider's web takes a huge amount of the insect's energy to build so it contains a series of features which stop major repairs being neededsource: dailymail
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