Not all spider silk is created equal. Some spiders spin webs of wet, sticky silk. Others like the Uloborus spider have fluffy webs made of nanoscale filaments. But those fluffy webs are just as good at catching prey, likely thanks to their electrostatic charge.
In a new paper published in Current Biology, scientists have figured out how the Uloborus spider spins its electrically charged web. The silk actually emerges as liquid from the spider's silk glands. As the spider pulls on the silk, it sets into a solid thread. But that's not all. Science's Monique Brouillette explains the rest:
In order to endow the fibres with an electrostatic charge, the spider pulls them over a comblike plate located on its hind legs. (This also gives the thread its wool-like appearance.) The technique is not unlike the so-called hackling of flax stems over a metal brush in order to soften and prepare them for thread-spinning, but in the spider's case it also gives them a charge. The electrostatic fibres are thought to attract prey to the web in the same way a towel pulled from the dryer is able to attract stray socks.
Spider silk, as you almost certainly know, is remarkable for its strength and lightness. Understanding how different types of spider silks are made could yield some insights on polymers used in industrial applications. Or, hopefully, applications in making a real-life electric Spider Man. [Current Biology via Science]
Silk spigots on the Uloborus spider. Pictures: Kronenberg et al