What keeps spiders on the ceiling?

DESYs X-ray source PETRA III reveals details of adhesive structures of spider legs

Hunting spiders easily climb vertical surfaces or move upside down on the ceiling. A thousand tiny hairs at the ends of their legs make sure they do not fall off. Like the spider’s exoskeleton, these bristle-like hairs (so-called setae) mainly consist of proteins and chitin, which is a polysaccharide. To find out more about their fine structure, an interdisciplinary research team from the Biology and Physics departments at Kiel University and the Helmholtz-Zentrum Geesthacht (HZG) examined the molecular structure of these hairs in closer detail at DESY’s X-ray light source PETRA III and at the European Synchrotron Radiation Facility ESRF. Thanks to the highly energetic X-ray light, the researchers discovered that the chitin molecules of the setae are specifically arranged to withstand the stresses of constant attachment and detachment. Their findings could be the basis for highly resilient future materials. They have been published in the current issue of the Journal of the Royal Society Interface.

>Read more on the PETRA III at DESY website

Image: In order to find out why the hunting spider Cupiennius salei adheres so well to vertical surfaces, the interdisciplinary research team investigates the tiny adhesive hairs on the spider legs.
Credit: Universität Kiel, Julia Siekmann