Synthetic gelatin-like material mimics lobster underbelly’s stretch and strength

A lobster’s underbelly is lined with a thin, translucent membrane that is both stretchy and surprisingly tough. This marine under-armor, as MIT engineers reported in 2019, is made from the toughest known hydrogel in nature, which also happens to be highly flexible. This combination of strength and stretch helps shield a lobster as it scrabbles across the seafloor, while also allowing it to flex back and forth to swim.

Now a separate MIT team has fabricated a hydrogel-based material that mimics the structure of the lobster’s underbelly. The researchers ran the material through a battery of stretch and impact tests, and showed that, similar to the lobster underbelly, the synthetic material is remarkably “fatigue-resistant,” able to withstand repeated stretches and strains without tearing. If the fabrication process could be significantly scaled up, materials made from nanofibrous hydrogels could be used to make stretchy and strong replacement tissues such as artificial tendons and ligaments.

The team also subjected the material to microballistic impact tests with an experiment designed by Nelson’s group. They imaged the material as they shot it with microparticles at high velocity, and measured the particles’ speed before and after tearing through the material. The difference in velocity gave them a direct measurement of the material’s impact resistance, or the amount of energy it can absorb, which turned out to be a surprisingly tough 40 kilojoules per kilogram. That means that a 5-millimeter steel ball launched at 200 meters per second would be arrested by 13 millimeters of the material. It is not as resistant as Kevlar, which would require 1 millimeter, but the material beats Kevlar in many other categories.

Read more at MIT

Image Credit: MIT

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