Kevlar, a synthetic fiber blend, has been stopping bullets for decades, but body armor could soon get a boost from a distinctly natural material. Wool added to Kevlar vests can improve their energy and water absorption, making waterproof, bulletproof vests that are both lighter in weight and cheaper to make, according to a study in Australia
Tightly woven wool reduces the number of Kevlar layers required to stop a bullet from 36 to 30, and wool expands when it absorbs water, which improves Kevlar's function when it's wet. Typically, Kevlar's bullet-stopping abilities are hampered in water, so it must be waterproofed in a lengthy and expensive process. Wool could be a cheap, renewable way to produce better body armor.