Spun from silk, with the strength of steel but with extraordinary elasticity, a spider's web has long been regarded as one of Mother Nature's most amazing feats. Now scientists at Oxford University have revealed another unique quality — webs actively spring towards prey thanks to electrically conductive glue spread across their surface.
Researchers discovered that the electrical properties of a glue that coats spider webs causes them to reach out to grab all charged particles, from pollen and pollutants to flying insects. The study, published in Naturwissenschaften journal, shows how a quirk of physics causes webs to move towards all airborne objects, regardless of whether they are positively or negatively charged. This explains why webs are able to spring towards prey and how they collect small airborne particles so efficiently.
Spider webs could, according to researchers, be used for environmental monitoring as they actively filter airborne pollutants with the same accuracy as expensive industrial sensors.
"Electrical attraction drags airborne pollutants to the webs, so you could harvest and test webs to monitor pollution levels — for example, to check for pesticides ," said Fritz Vollrath of Oxford University's department of zoology, who led the study.
"You can detect some airborne chemicals just by looking at the shape of the webs. Many spiders clear particles from their webs by eating them, including chemicals that are drawn to the web." In tests, spiders are known to create different qualities of web depending on their consumption of narcotic drugs, Vollrath said.
The researchers found that the spider webs cause local distortions in the Earth's electric field since they behave like conducting discs.