Spider silk is one of the strongest known materials with its incredible strength-to-weight ratio, resilience and toughness. Scientists now plan to use the spider silk in robotics.
Researchers from Massachusetts Institute of Technology (MIT) recently discovered an unusual property of the spider silk called ‘supercontraction’ wherein the fibers of spider silk can suddenly shrink in response to changes in moisture. In fact, the fibers don’t just contract but they also twist at the same time, providing a strong torsional force.
This unusual property of the spider silk can be used to create artificial muscles and robotic actuators.
The discovery was made by chance
During an experiment, researchers tied a weight to the end of spider silk and created a pendulum inside a chamber where they could control the relative humidity inside. When they increased the humidity, the pendulum started to rotate which was beyond their expectations. The researchers were surprised, they tried other materials such as human hair to check this property, but none of the materials had the twisting property.
This outstanding performance can now be harnessed to build humidity-driven soft robots, smart fabrics or sensors or control devices that can be managed by controlling the humidity or respond to humidity.