Ilaria Rosella Pagliaro Thanks to an accidental discovery, researchers at Tufts University have created a silk fiber that instantly solidifies and lifts objects 80 times heavier than itself
A team of researchers at SilkLab, Tufts University, has recently developed an extraordinary material: a silk-based viscous substance that instantly solidifies into a durable fiber when expelled from a needle. This fiber can lift objects up to 80 times its own weight, bringing us closer to the technology behind the famous web-slinging feats of comic book hero Spider-Man.
How the silk-based “Spider-Man” fiber was born
The idea to develop this unique fiber emerged somewhat by accident. Marco Lo Presti, lead author of the study and associate professor at Tufts University, was working on creating strong adhesives using silk fibroin, a protein produced by silkworms. During an experiment, Lo Presti observed that the substance formed a web-like structure at the bottom of a glass container cleaned with acetone. Intrigued by this, the team decided to experiment further. They mixed the fibroin with acetone, producing a semi-solid hydrogel. When dopamine was added to the mixture, the liquid compound solidified almost immediately, forming a sticky, highly resilient fiber.
Unsatisfied with the initial results, the researchers then added chitosan, a natural biopolymer derived from crustacean shells, which improved both the fiber’s adhesion and durability—boosting them by 18% and 200%, respectively. The team then developed a device capable of “firing” the liquid toward objects, successfully lifting steel bolts at a distance of approximately 5 inches and weighing up to 80 times the fiber’s own weight.
Why not use spider silk?
While spider silk is renowned for being one of nature’s strongest materials—boasting a strength-to-weight ratio that surpasses steel—the researchers chose to work with silkworm silk fibroin. Artificially reproducing spider silk is significantly more complex, and its characteristics can vary widely across spider species, making it challenging to use reliably and consistently.
In contrast, silkworm silk is easy to produce and modify in a lab setting, allowing researchers to adjust its strength and stickiness according to the requirements of various applications. This versatility makes it suitable for soft robotics, drug delivery, and even biodegradable sensors.
