Spider silk is an amazing material known to have a strength to weight ratio comparable to some steel alloys. However, a group of professors and students at Massachusetts Institute of Technology found an even more amazing (and useful) discovery. Spider silk was found to have a super contraction quality in the presences of moisture. They found this property accidentally when a strand of the silk started to rotate and coil during a study looking at the effects of humidity on spider silk. Upon further investigation, the phenomenon the researchers discovered had immediate applicability to robotics and prosthetics.
Currently actuators simulate muscle movements in several forms: electric, pneumatic, and thermal actuation. A large number of the artificial muscles on the market today use Nylon, a non-biodegradable material that is largely responsible for the pollution of the ocean in the form of micro-plastics. The production of Nylon also releases greenhouse gas, nitrous oxide, a major contributor in global warming. As the demand for more intricate prosthetics and robots increases, contributions to pollution and global warming will only get worse if an alternative cannot be found. Although spider silk could be this perfect substitution, as of today the supply of spider silk unfortunately is not enough to warrant this switch. However, research on generating synthetic spider silk through genetic engineering is making headway. Researchers at the University of Washington in St. Louis discovered a way to make genetically-synthesized spider silk that can rival the real thing just this past year! With this new and exciting discovery of super contraction there may be enough interest from private sectors to invest in creating genetically-synthesized spider silk to replace the Nylon currently being used in so many products today. If done, this manufacturing process could have a great impact not only in the engineering and robotics world, but also in the health and sustainability of our global environment.