Learn fluid armor technology

New armor production technology helps to reduce volume and increase the flexibility of outdated armor .

In combat, in addition to weapons, armor is an integral part of every soldier. Since ancient times, our fathers have known to use materials such as iron, steel, even ceramics, straw . as armor to protect our bodies. Through the ups and downs of time, the idea of ​​armor is not much changed. First, armor helps protect the body of the user. Second, it diffuses the energy of weapons and reduces damage. Although in some situations, armor is not very effective, but at the very least, it can protect the human body from fatal blows, especially long-range weapons like guns.

With the development of science and technology over the years, the advanced armor has been researched and manufactured, successfully applied on the battlefield. However, they still have many shortcomings and weaknesses like their older men. Many types of armor made of metal or cloth are still quite heavy and bulky. So many people only use armor to protect their body and head, rarely used on the legs, arms and neck. This is the biggest drawback of the armor we still see.

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The difference between the ancient armor and the modern armor

And liquid armor is the latest breakthrough in the bulletproof armor manufacturing industry. Besides using high hardness materials, some special fluids are used to increase their effectiveness. This type of armor is very flexible and lightweight, the user can use it to protect arms, legs or neck without affecting the movement of the body.

This loose armor is based on the Kevlar fiber, which is often used in bulletproof suits. The principle of the suit is quite simple: when the bullet hits the surface of the suit, the Kevlar layer will disperse the impact force to the entire surface and reduce the speed of the bullet. This process is similar to an airbag in a car that opens when a shock occurs. However, this type of armor requires 20 to 40 Kevlar layers to prevent a bullet. Therefore, the suit becomes rigid and heavy (about 4.5kg), making it difficult for users. But with the new fluid technology will allow to reduce Kevlar layers, making the armor much lighter and more flexible.

There are 2 types of liquid here, corresponding to 2 new types of bulletproof vests:

- Shear-Thickening Fluid (STF): Liquid has the ability to suddenly freeze when there is an external force.

- Magnetorheological Fluid (MR): The liquid has the ability to suddenly freeze when there is a magnetic field effect.

Shear-Thickening Fluid (STF)

STF is a rather special mixture that exists in liquid form but when it has a strong impact it can freeze immediately. In fact, this hardening process takes only a few milliseconds and when there is no longer the impact force it will return to its initial liquid state. It is similar to a mixture of cornstarch with water. If you stir this mixture slowly, it is no different from a normal liquid. But when you hit it hard, it will be as hard as a concrete block.

This process is explained as follows: STF is essentially a colloid, consisting of small particles suspended in it. These particles repel each other, so they can float, floating in the liquid without sinking down. When a force is applied, it overwhelms the repulsive force of these particles, causing them to stick together, forming a mass called the Hydrocluster . When the external force disappears, the particles continue to repel each other. The Hydrocluster block disintegrates and the substance that seems to be solid has returned to a liquid state.

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When impacting the silica particles stick together to form a solid protective layer (pictured below)

The type of liquid that researchers use in liquid armor is glyco polyethylene, while the particles inside it are silica (silicon dioxide). Silica is a component of sand and quartz and Glyco PolyEtylen is used in laxatives or lubricants. Silica particles have a diameter of only a few nanometers, so many reports describe this liquid as a product of nanotechnology.

How to create an armor using STF

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A STF liquid armor after being hit

The researchers first diluted STF liquid in ethanol solution. Then dip Kevlar fiber through this mixture and place it in the oven to evaporate the ethanol. STF penetrates into Kevlar fibers and adds strength to them. When there is force exerted from the outside into this Kevlar-permeable STF layer, they will harden and eliminate the strength of the object. And after the block is finished, the fiber will soften as usual. Thus, there is no need for too many Kevlar layers, but the armor is still strong and effective. In fact, people only need these 4 Kevlar layers to be as effective as 14 normal Kevlar layers.

Another type of liquid used in liquid armor technology is:

Magnetorheological (MR) Fluid

MR liquid is an oil and contains iron particles suspended inside. Usually these iron particles account for about 20 to 40% of the liquid mass. These particles are very small, about 3 to 10 micrometers in size. They are small, but they have a strong impact on the hardness of MR liquids. When exposed to magnetic fields, iron particles will stick together, form rows and form an extremely protective layer of iron.

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The hardened MR liquid has the effect of magnetic field

The hardening process of this liquid is about 20 milliseconds. The freezing effect can vary considerably, all depending on the liquid composition and size, shape, and strength of the magnetic field. For example, researchers can choose spherical iron particles, which can slip through each other easily, even in the presence of a magnetic field. Therefore, the hardness of this granular fluid is not guaranteed. They are finding another iron grain structure to be more effective.

Only with iron filings and oil are you able to produce a mixture that is similar to MR liquid used in this liquid armor technology. When there is no magnetic field, this liquid moves easily. But the effect of a magnet can make it thicker, forming a certain shape as a solid object. With a density, iron particle shape and magnetic field are suitable. MR liquid can transform into an extremely solid solid.

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MR liquid after impact of magnetic field

The construction of a basic MR armor is similar to that of STF, which greatly increases the effectiveness of the armor. However, one weakness of this armor is that there must be magnetic fields, then MR actually works . The idea of ​​the magnets attached to the shirt seems to solve this problem, but if you do that, the armor is always in a hard and heavy state, it's hard to move. So scientists attached small circuits around the armor. Without the current flowing, the armor was still soft and flexible. But when the switch is turned on, electric current will begin to move, creating magnetic fields that stimulate iron particles in MR liquid. Turning off the switch, the armor returns to its normal state.

These two types of fluids are not only used in the manufacture of bulletproof armor, but also countless other applications. For example, bomb-resistant blankets can be easily folded, more mobile in protecting the surrounding people from explosion damage. This new technology can also be used in making paratroopers' shoes or making uniforms for prison guards .