Scientists Recreate Spider-Man’s Web Slinging Technology With Liquid Silk
The liquid silk threads can stick to various objects and lift more than 80 times their own weight.
Complete the form below to unlock access to ALL audio articles.
Don’t worry Spider-Man, it’s not Doctor Octopus who has figured out the secret of your web-shooters – it’s researchers at Tufts University.
While working on a separate project involving extra-strong adhesives, the Tufts University Silklab team discovered that the silk from silk moth cocoons can be turned into a shootable, sticky protein solution that works surprisingly like Spider-Man’s famous sticky webs.
The unique solution can be shot out of a needle, solidifying immediately into a sticky web-like fiber that can lift objects more than 80 times its own weight. Their research is published in Advanced Functional Materials.
Recreating Spider-Man’s super silk
To make these superhero-like silk threads, the researchers boiled and washed silk moth cocoons in various solutions until all of its silk fibroin had been isolated and extracted. Silk fibroin is a fibrous protein that is the primary component of silk moth silks.
Previous studies have shown that combining silk fibroin solutions with dopamine can result in very strong bioadhesives. Separately, it is also known that silk fibroin will begin to form a semi-solid hydrogel over several hours when mixed with organic solvents like ethanol or acetone.
The Tufts University researchers discovered that by adding dopamine to their silk fibroin mix, the solidification process is triggered almost immediately as the dopamine pulls water away from the silk. This results in the formation of sticky silk fibers with a high tensile strength.
They also found that these fibers could be spun in the air by shooting them through a needle. Immediately after leaving the needle, the thin stream of silk solution is covered by a layer of acetone that triggers the solidification process. But as the stream continues to travel through the air, the acetone evaporates, exposing the sticky silk fiber surface that can adhere to objects.
“If you look at nature, you will find that spiders cannot shoot their web. They usually spin the silk out of their gland, physically contact a surface and draw out the lines to construct their webs,” said Marco Lo Presti, a research assistant professor in biomedical engineering at Tufts University.
“We are demonstrating a way to shoot a fiber from a device, then adhere to and pick up an object from a distance. Rather than presenting this work as a bio-inspired material, it’s really a superhero-inspired material.”
Subscribe to Technology Networks’ daily newsletter, delivering breaking science news straight to your inbox every day.Want more breaking news?
By adding chitosan, a derivative of insect exoskeletons, and a borate buffer to the silk solution, the research group was able to further improve the fibers’ tensile strength by up to 200 times and their adhesiveness around 18-fold.
The result is a thin fiber – with a diameter as thin as a human hair depending on the needle bore – that can pick up objects more than 80 times its own body weight. The team has demonstrated its flexibility by picking up a cocoon, a steel bolt, a laboratory tube floating on water, a scalpel partially buried in sand and a wood block.
An accidental breakthrough
In nature, all manner of spiders, butterflies, moths, beetles and even bees produce silk at some point in their lives to fulfill some kind of need – whether that be to build a web or a nest, or to produce a cocoon.
The Silklab researchers take inspiration from how silk fibers are deployed in nature and pioneer the use of silk fibroin in making powerful underwater adhesives, printable sticky sensors, edible coatings for perishable produce, novel light-collecting materials for solar cells and more.
Surprisingly, this latest discovery came about by accident while carrying out a separate project on adhesives.
“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,” Lo Presti said.
While scientists have previously created numerous adhesives inspired by animal silk or based on artificial silks, this is the first successful attempt at developing a material that can be instantaneously spun into adhesive fibers, the researchers say.
“As scientists and engineers, we navigate the boundary between imagination and practice. That’s where all the magic happens,” said Fiorenzo Omenetto, Frank C. Doble Professor of Engineering at Tufts University and director of the Silklab. “We can be inspired by nature. We can be inspired by comics and science fiction. In this case, we wanted to reverse engineer our silk material to behave the way nature originally designed it, and comic book writers imagined it.”
Reference: Lo Presti M, Portoghese M, Farinola GM, Omenetto FG. Dynamic adhesive fibers for remote capturing of objects. Adv Funct Mater. 2024:2414219. doi: 10.1002/adfm.202414219
This article is a rework of a press release issued by Tufts University. Material has been edited for length and content.