Inspired by Spider-Man, scientists recreate web-slinging technology

Summary

We all have moments as kids watching Spider-Man and imagining what it might feel like to shoot a thread into the air and have it grab something, bringing it closer. A group of researchers at Tufts University has moved that idea from comic panels into the lab. Their new work shows a fluid silk material that shoots from a needle, solidifies mid-air, sticks to objects, and can lift items far heavier than itself. The whole story began with silk, not the kind spiders spin, but the silk taken from moth cocoons, which are boiled down into their basic protein building blocks known as fibroin. The silk fibroin solution can be pushed through narrow-bore needles to make thin threads, and when exposed to solvents like ethanol or acetone, it slowly starts turning into a semi-solid hydrogel. The problem is that this transformation usually takes hours. Spider silk hardens almost instantly as it leaves the glands, which gives spiders the precise control that engineers have struggled to match. Also Read: Physicists Prove the Universe Is Not a Computer Simulation Then a little accident helped make a breakthrough. “I was working on a project making extremely strong adhesives using silk fibroin, and while I was cleaning my glassware with acetone, I noticed a web-like material forming on the bottom of the glass,” said Marco Lo Presti, research assistant professor at Tufts. It turned out that dopamine, a key component they were already using for adhesive work, dramatically sped up the solidification process. When dopamine is mixed into the solution, it appears to pull water away from the silk proteins, so the liquid fibroin doesn’t need hours to set. Instead, once it meets the organic solvent, it snaps into a fiber in just seconds. VIDEO From there, the team built a coaxial needle system where the fibroin–dopamine solution moves through the center while a layer of acetone flows around it. As the stream leaves the nozzle, the acetone triggers rapid solidification and then evaporates in mi...