A research team from the Massachusetts Institute of Technology (MIT) have found that spider silk contains a property that could be useful in the development of artificial, robotic muscle. When humidity goes up, the fibers of a spider's web suddenly become taught with supercontraction. The silk also twists at the same time, giving a strong torsional force. They also believe this ultra-fine but durable material could one day be used as an artificial muscle.

Spider silk, already known as one of the strongest materials for its weight, turns out to have another unusual property that might lead to new kinds of artificial muscles or robotic actuators, researchers have found. A team from MIT and Huazhong University of Science and Technology has showed that spider silk could contract and twist in humidity that can be used to make artificial muscle or robotic actuators. The demonstrated that slender spider fibers could suddenly shrink in response to changes in moisture, hence portraying a strong torsional force, a process known as'supercontraction'. The team suspended a weight from the spider silk to make a type of pendulum. They then enclosed it in a chamber where they could control the relative humidity inside.

Scientists have discovered a remarkable property of a certain type of spider silk: It acts like a solid when you stretch it, but liquid when you squish it. And they've proven that they understand how this "liquid wire" works by actually creating synthetic strands that can do the exact same thing -- solving a decades-old mystery in the process. The findings, described in the Proceedings of the National Academy of Sciences, reveal the bizarre phenomenon that may help spider webs remain taut, and could offer fresh insight for a range of technologies, including soft robotics. Spiders spin a range of web shapes, from funnels to nests, but the classic orb-like structures remain something of an archetype. Such webs typically have sticky droplets of glue on the strands of capture thread – the segments of spider silk that connect the radiating branches of these disc-like webs.