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Progress in material science

Ballistic vests use layers of very strong fibers to "catch" and deform a bullet, mushrooming it into a dish shape, and spreading its force over a larger portion of the vest fiber. The vest absorbs the energy from the deforming bullet, bringing it to a stop before it can completely penetrate the textile matrix. Some layers may be penetrated but as the bullet deforms, the energy is absorbed by a larger and larger fiber area.

In recent years, advances in material science have opened the door to the idea of a literal "bulletproof vest" able to stop handgun and rifle bullets with a soft textile vest, without the assistance of additional metal or ceramic plating. However, progress is moving at a slower rate compared to other technical disciplines. The most recent offering from Kevlar, Protera, was released in 1996. Current soft body armor can stop most handgun rounds (which has been the case for roughly 15 years), but armor plates are needed to stop rifle rounds and steel-core handgun rounds such as 7.62×25mm. The para-aramids have not progressed beyond the limit of 23 grams per denier in fiber tenacity.

Modest ballistic performance improvements have been made by new producers of this fiber type. Much the same can be said for the UHMWPE material; the basic fiber properties have only advanced to the 30–35 g/d range. Improvements in this material have been seen in the development of cross-plied non-woven laminate, e.g. Spectra Shield. The major ballistic performance advance of fiber PBO is known as a "cautionary tale" in materials science. This fiber permitted the design of handgun soft armor that was 30–50% lower in mass as compared to the aramid and UHMWPE materials. However this higher tenacity was delivered with a well-publicized weakness in environmental durability.

Akzo-Magellan (now DuPont) teams have been working on fiber called M5 fiber; however, its announced startup of its pilot plant has been delayed more than 2 years. Data suggests if the M5 material can be brought to market, its performance will be roughly equivalent to PBO. In May 2008, the Teijin Aramid group announced a "super-fibers" development program. The Teijin emphasis appears to be on computational chemistry to define a solution to high tenacity without environmental weakness.

The materials science of second generation "super" fibers is complex, requires large investments, and represent significant technical challenges. Research aims to develop artificial spider silk which could be super strong, yet light and flexible. Other research has been done to harness nanotechnology to help create super-strong fibers that could be used in future bulletproof vests. In 2018, the US military began conducting research into the feasibility of using artificial silk as body armor, which has the advantages of its light weight and its cooling capability.