Simulate snail shells to make armor, helmets ...

The latest research on the three-layer shell structure of a seabed snail can lead to the introduction of helmets, armor, cars, motorcycles, oil pipelines . The new generation has the ability to dissipate the impact force.

The scaly leg snail has a scientific name, Crysomallon squamiferum , discovered in the Indian Ocean at a depth of 2.4 km. Previous studies have shown that the snail's legs are covered with thin plates made of iron sulfide.

The latest study found that this is the only animal that uses iron sulfide as its structural material. Professor Christine Ortiz and colleagues at the Massachusetts Institute of Technology (US) have discovered the snail's defense secret before the attack of mud crabs. The shells of other snails crack when they are stolen.

Hard as iron, soft like cotton

To assess the strength and rigidity of the shells, researchers used diamond-pierced drill bits with an equivalent force of stealing. They then used the collected data to model the shells' layers and simulate a crab attack on the shell.

The study results show that scaly leg snails have some very unique 'tricks' to protect themselves. For example, the outer layer of the shell consists of iron sulfide particles created at the hydrothermal vents on the sea floor.

Each particle has a diameter of about 20 nanometers (nm) of iron sulfide particles hidden deep in a layer of organic matter released by snails. This structure is designed so that when impacted, the shell will crack but in the direction of energy absorption, eliminate the impact force.

The squid that lives at depths of more than 2.4 km in the Indian Ocean has a superior "armor".Photo: Anders Warén.

Stretch marks spread only fan-shaped around iron sulfide particles. This type of mini reef not only absorbs energy but also ensures that larger cracks do not appear. Research results also show that iron sulfide particles can cause abrasion and deformation of crabs.

The middle layer of the snail shell is thick and spongy, serving as a cushion to further dissipate the impact force. This reduces the likelihood of fragility of the fragile innermost layer fragile because it is made up of calcium carbonate.

According to Ms. Ortiz, the middle layer of the shell can be an important adaptation of this mollusk in the harsh seabed environment. Acid water near hydrothermal vents dissolves calcium carbonate and quickly increases the risk of rupture.

As a bodyguard, the middle layer prevents the dissolution of calcium carbonate in the outer layer as well as protecting the snail from temperature changes in hydrothermal vents.

Application on protective gear

The three-layer 'hard - soft - hard' design can be used to improve the body and sports apparel for the human body without increasing the volume, Ms. Ortiz said.

The armor will be coated with a nano-sized grain of iron particles to dissipate the impact force. This principle of energy absorption and elimination of this force can also be applied in the field of manufacturing helmets, motorcycles, cars and oil pipelines that often collide with icebergs.

'This is the first step in the path to understanding how to create a technical system that mimics the protective structure of organisms,' said Ms. Ortiz. She is studying the construction of protection and protection systems based on the composition of some animal species such as birch snail, sea urchin, beetle, Senegal squid .

Nature-inspired designs may not use all the materials found in sea shells. Scientists will consider it a guide to improving many types of products in the future.

'Nature only uses what is available,' said Ms. Ortiz. Architects can use the same design but replace some materials with better physical and chemical properties.