Editing Bulletproof vest (section)

==Research==

===Non-standard designs of hard armour===
The vast majority of hard body armor plates, including the U.S. military's [[Small Arms Protective Insert]] family, are monolithic; their strike faces consist of a single ceramic tile. Monolithic plates are lighter than their non-monolithic counterparts, but suffer from reduced effectiveness when shot multiple times in a close area (i.e., shots spaced less than two inches/5.1&nbsp;cm apart). However, several non-monolithic armor systems have emerged, the most well-known being the controversial [[Dragon Skin]] system. Dragon Skin, composed of dozens of overlapping ceramic scales, promised superior multi-hit performance and flexibility compared to the then-current ESAPI plate; however, it failed to deliver. When the U.S. Army tested the system against the same requirements as the ESAPI, Dragon Skin showed major issues with environmental damage; the scales would come apart when subjected to temperatures above 120&nbsp;°F (49&nbsp;°C) – not uncommon in Middle Eastern climates – when exposed to diesel vehicle fuel, or after the two four-foot drop tests (after these drops, ESAPI plates are put in an X-ray machine to determine the location of cracks, and then shot directly on said cracks), leaving the plate unable to reach its stated threat level and suffering 13 first- or second-shot complete penetrations by .30–06 M2 AP (the ESAPI test threat) out of 48 shots.<ref>{{Cite web|url=https://archive.defense.gov/DODCMSShare/briefingslide/304/070521-D-6570C-001.pdf|title=Dragon Skin Environmental Testing|access-date=2019-12-22|archive-date=2016-12-22|archive-url=https://web.archive.org/web/20161222212514/https://archive.defense.gov/DODCMSShare/briefingslide/304/070521-D-6570C-001.pdf|url-status=dead}}</ref>

Perhaps less-well known is LIBA (Light Improved Body Armor), manufactured by Royal TenCate, ARES Protection, and Mofet Etzion in the early 2000s. LIBA uses an innovative array of ceramic pellets embedded in a polyethylene backer;<ref name="Patent for lightweight composite armor that uses LIBA as an example of commercial non-monolithic armor.">{{cite web |title=Lightweight composite armor |url=https://patents.justia.com/patent/7694621 |website=JUSTIA Patents |publisher=MKP Structural Design Associates, Inc. |access-date=6 April 2020}}</ref><ref>{{Cite web|url=https://imgur.com/8q0qXMb|title=LIBA armor makeup}}</ref> although this layout lacks the flexibility of Dragon Skin, it provides impressive multi-hit ability as well as the unique ability to repair the armor by replacing damaged pellets and epoxying them over.<ref>{{Cite web|url=https://imgur.com/HkvWT35|title=LIBA 15 hits from 7.62 AK fire}}</ref><ref name="Official Mofet Etzion video showcasing repair of a LIBA insert.">{{cite web |author1=Mofet Etzion |title=Mofet Etzion |url=https://www.youtube.com/watch?v=89JHLN4atHw  |archive-url=https://ghostarchive.org/varchive/youtube/20211211/89JHLN4atHw| archive-date=2021-12-11 |url-status=live|website=YouTube |date=5 March 2018 |access-date=6 April 2020}}{{cbignore}}</ref> In addition, there are variants of LIBA with multi-hit capacity against threats analogous to [[7.62×51mm NATO]] M993 AP/WC,<ref>{{Cite web|url=https://imgur.com/40vzOtg|title="Super LIBA" back, shows the rating as 7.62 WC.}}</ref> a tungsten-cored armor-piercing round. Field tests of LIBA have yielded successful results, with 15 AKM hits producing only minor bruises.<ref>{{Cite web|url=http://www.mofet-etzion.co.il/combat_proven.html|title=15 hits of 7.62x39mm on a LIBA plate, Golan Heights 2002.|url-status=live|archive-url=https://web.archive.org/web/20070221002919/http://www.mofet-etzion.co.il/combat_proven.html|archive-date=2007-02-21}}</ref>

===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 {{Citation needed|date=July 2010}}), 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&nbsp;grams per [[Units of textile measurement#Denier|denier]] in fiber tenacity.

Modest ballistic performance improvements have been made by new producers of this fiber type.<ref>Heterocyclic Aramide Fibers – Production Principles, Properties and Application, Nikolay N. Machalaba and Kirill E. Pekin</ref> 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 [[Zylon|PBO]] is known as a "cautionary tale" in materials science.<ref>Morphological study on poly-p-phenylenebenzobisoxazole (PBO) fiber, Tooru Kitagawa *, Hiroki Murase, Kazuyuki Yabuki Toyobo Research Center, Toyobo Co. Ltd., 2-1-1, Katata, Ohtsu 520-02 Japan</ref> 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.<ref name="Cunniff">{{cite web |last1=Cunniff |first1=Philip M. |last2=Auerbach |first2=Margaret |last3=Vetter |first3=Eugene |last4=Sikkema |first4=Doetze J |title=High Performance "M5" Fiber for Ballistics/Structural Composites |url=http://web.mit.edu/course/3/3.91/OldFiles/www/slides/cunniff.pdf |journal= |archive-url=https://web.archive.org/web/20041118190203/http://web.mit.edu/course/3/3.91/OldFiles/www/slides/cunniff.pdf |archive-date=18 November 2004}}</ref> 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.<ref name="Lazaris2002">{{cite journal |title=Spider Silk Fibers Spun from Soluble Recombinant Silk Produced in Mammalian Cells |first1=Anthoula |last1=Lazaris |first2=Steven |last2=Arcidiacono |first3=Yue |last3=Huang |first4=Jiang-Feng |last4=Zhou |first5=François |last5=Duguay |first6=Nathalie |last6=Chretien |first7=Elizabeth A |last7=Welsh |first8=Jason W |last8=Soares |first9=Costas N |last9= Karatza   |s2cid=9260156 |journal=Science |volume=295 |issue=5554 |pages=472–476 |doi=10.1126/science.1065780 |pmid=11799236 |year=2002|bibcode=2002Sci...295..472L }}</ref> 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.<ref>{{cite web|url=https://www.af.mil/News/Article-Display/Article/1596954/air-force-scientists-study-artificial-silk-for-body-armor-parachutes/|title=Air Force scientists study artificial silk for body armor, parachutes|date=8 August 2018 }}</ref>

===Textile wovens and laminates research===
Finer yarns and lighter woven fabrics have been a key factor in improving ballistic results. The cost of ballistic fibers increases dramatically as the yarn size decreases, so it's unclear how long this trend can continue. The current practical limit of fiber size is 200 denier with most wovens limited at the 400 denier level. Three-dimensional weaving with fibers connecting flat wovens together into a 3D system are being considered for both hard and soft ballistics. Team Engineering Inc is designing and weaving these multi layer materials. Dyneema DSM has developed higher performance laminates using a new, higher strength fiber designated SB61, and HB51. DSM feels this advanced material provides some improved performance, however the SB61 "soft ballistic" version has been recalled.<ref>{{Cite web|url=https://cjtec.org/|archive-url=https://web.archive.org/web/20070528055600/http://www.justnet.org/BatPro/|url-status=dead|title=Home – Criminal Justice Testing and Evaluation Consortium (CJTEC)|archive-date=May 28, 2007|website=cjtec.org}}</ref>  At the Shot Show in 2008, a unique composite of interlocking steel plates and soft UHWMPE plate was exhibited by TurtleSkin.<ref>{{cite magazine |url=https://www.wired.com/2008/02/turtleskin-body/ |title=Shot Show:Pistol-stoppin TurtleSkin armour |magazine=Wired |date=4 February 2008}}</ref> In combination with more traditional woven fabrics and laminates a number of research efforts are working with ballistic felts. Tex Tech has been working on these materials. Like the 3D weaving, Tex Tech sees the advantage in the 3-axis fiber orientation.

===Fibers used===
Ballistic nylon (until the 1970s) or Kevlar, [[Twaron]]<ref>{{Cite web|url=http://www.differencebetween.net/object/differences-between-kevlar-and-twaron/|title=Differences Between Kevlar and Twaron|website=www.differencebetween.net|date=3 April 2013 |language=en-US|access-date=2018-03-30}}</ref> or Spectra (a competitor for Kevlar) or polyethylene fiber could be used to manufacture bullet proof vests. The vests of the time were made of ballistic nylon & supplemented by plates of fiber-glass, steel, ceramic, titanium, Doron & composites of ceramic and fiberglass, the last being the most effective.

===Developments in ceramic armor===
Ceramic materials, materials processing and progress in ceramic penetration mechanics are significant areas of academic and industrial activity. This combined field of ceramics armor research is broad and is perhaps summarized best by The American Ceramics Society. ACerS has run an annual armor conference for a number of years and compiled a proceedings 2004–2007.<ref>Wiley Advances in Ceramic Armor III ACS</ref> An area of special activity pertaining to vests is the emerging use of small ceramic components. Large torso sized ceramic plates are complex to manufacture and are subject to cracking in use. Monolithic plates also have limited multi hit capacity as a result of their large impact fracture zone. These are the motivations for new types of armor plate. These new designs use two- and three-dimensional arrays of ceramic elements that can be rigid, flexible, or semi-flexible. [[Dragon Skin (body armor)|Dragon Skin body armor]] is one of these systems. European developments in spherical and hexagonal arrays have resulted in products that have some flex and multi hit performance.<ref>Tencate AresShield</ref> The manufacture of array type systems with flex, consistent ballistic performance at edges of ceramic elements is an active area of research. In addition advanced ceramic processing techniques arrays require adhesive assembly methods. One novel approach is use of hook and loop fasteners to assemble the ceramic arrays.<ref>Foster Miller Last Armor.</ref>

===Nanomaterials in ballistics===
Currently, there are a number of methods by which [[nanomaterials]] are being implemented into body armor production. The first, developed at [[University of Delaware]] is based on [[nanoparticle]]s within the suit that become rigid enough to protect the wearer as soon as a kinetic energy threshold is surpassed. These coatings have been described as [[dilatant|shear thickening]] fluids.<ref name="Lee2003">{{cite journal |title=The ballistic impact characteristics of Kevlar woven fabrics impregnated with a colloidal shear thickening fluid |first1=Young S |last1=Lee |first2=E D |last2=Wetzel |first3=N J |last3=Wagner |journal=Journal of Materials Science |volume=38 |issue=13 |date=July 2003 |pages=2825–2833 |doi=10.1023/A:1024424200221|bibcode=2003JMatS..38.2825L|s2cid=136105658 }}</ref> These nano-infused fabrics have been licensed by BAE systems, but as of mid-2008, no products have been released based on this technology.

In 2005 an Israeli company, [[ApNano]], developed a material that was always rigid. It was announced that this [[nanocomposite]] based on [[tungsten disulfide nanotube]]s was able to withstand shocks generated by a steel projectile traveling at velocities of up to 1.5&nbsp;km/s.<ref name="NanoArmorProtecting">{{cite web|url=http://www.isracast.com/tech_news/091205_tech.htm |title=Nano-Armor: Protecting The Soldiers Of Tomorrow |publisher=Isracast.com |access-date=2009-04-06| archive-url= https://web.archive.org/web/20090406023428/http://www.isracast.com/tech_news/091205_tech.htm| archive-date= 6 April 2009 | url-status= live}}</ref> The material was also reportedly able to withstand shock pressures generated by other impacts of up to 250 metric tons-force per square centimeter (24.5 [[Pascal (unit)|gigapascal]]s; 3,550,000 psi). During the tests, the material proved to be so strong that after the impact the samples remained essentially unmarred. Additionally, a study in France tested the material under [[Isostasy|isostatic]] pressure and found it to be stable up to at least 350 tf/cm<sup>2</sup> (34 GPa; 5,000,000 psi).

As of mid-2008, spider silk bulletproof vests and nano-based armors are being developed for potential market release.{{Citation needed|date=November 2009}} Both the British and American militaries have expressed interest in a [[carbon (fiber)|carbon fiber]] woven from [[carbon nanotube]]s that was developed at [[University of Cambridge]] and has the potential to be used as body armor.<ref name="Rincon2007">{{cite news|last=Rincon |first=Paul |url=http://news.bbc.co.uk/1/hi/sci/tech/7038686.stm |title=Science/Nature &#124; Super-strong body armour in sight |work=BBC News |date=2007-10-23 |access-date=2009-04-06}}</ref> In 2008, large format carbon nanotube sheets began being produced at Nanocomp. {{citation needed|date=June 2019}}

===Graphene composite===
In late 2014, researchers began studying and testing [[graphene]] as a material for use in body armor. Graphene is manufactured from carbon and is the thinnest, strongest, and most conductive material on the planet. Taking the form of hexagonally arranged atoms, its tensile strength is known to be 200 times greater than steel, but studies from [[Rice University]] have revealed it is also 10 times better than steel at dissipating energy, an ability that had previously not been thoroughly explored. To test its properties, the [[University of Massachusetts]] stacked together graphene sheets only a single carbon atom thick, creating layers ranging in thickness from 10 nanometers to 100 nanometers from 300 layers. Microscopic spherical [[silica]] "bullets" were fired at the sheets at speeds of up to 3&nbsp;km (1.9&nbsp;mi) per second, almost nine times the speed of sound.  Upon impact, the projectiles deformed into a cone shape around the graphene before ultimately breaking through. In the three nanoseconds it held together however, the transferred energy traveled through the material at a speed of 22.2&nbsp;km (13.8&nbsp;mi) per second, faster than any other known material. If the impact stress can be spread out over a large enough area that the cone moves out at an appreciable velocity compared with the velocity of the projectile, stress will not be localized under where it hit. Although a wide impact hole opened up, a composite mixture of graphene and other materials could be made to create a new, revolutionary armor solution.<ref>[http://www.armedforces-int.com/news/worlds-strongest-material-in-body-armour-trials.html World's Strongest Material In Body Armour Trials] {{Webarchive|url=https://web.archive.org/web/20141209084435/http://www.armedforces-int.com/news/worlds-strongest-material-in-body-armour-trials.html |date=2014-12-09 }} – Armedforces-Int.com, 1 December 2014</ref><ref>[http://www.gizmag.com/graphene-bulletproof-armor/35004/ Graphene could find use in lightweight ballistic body armor] – Gizmag.com, 1 December 2014</ref>