How spider webs achieve their strength
The silk that spiders use to build their webs, trap their prey and dangle from your ceiling is one of the strongest materials known. But it turns out it’s not simply the material’s exceptional strength that makes spider webs so resilient; it’s the material’s unusual combination of strength and stretchiness — silk’s characteristic way of first softening and then stiffening when pulled. These properties, scientists have found, vary depending on the forces applied, as well as on the overall design of the web.Markus Buehler, an associate professor of civil and environmental engineering (CEE) at MIT, has previously analyzed the complex, hierarchical structure of spider silk and its amazing strength — on a pound-for-pound basis, it’s stronger than steel. Now, Buehler and his colleagues have applied their analysis to the structure of the webs themselves, finding evidence of the key properties that make webs so resilient and relating those properties back...