Liquid armor for Kevlar vests is one of the newest technologies being developed at the U.S. Army Research Laboratory to save Soldiers’ lives.
This type of body armor is light and flexible, which allows soldiers to be more mobile and won’t hinder an individual from running or aiming his or her weapon.
The key component of liquid armor is a shear thickening fluid. STF is composed of hard particles suspended in a liquid. The liquid, polyethylene glycol, is non-toxic, and can withstand a wide range of temperatures. Hard, nano-particles of silica are the other components of STF. This combination of flowable and hard components results in a material with unusual properties.
“During normal handling, the STF is very deformable and flows like a liquid. However, once a bullet or frag hits the vest, it transitions to a rigid material, which prevents the projectile from penetrating the Soldier’s body,” said Dr. Eric Wetzel, a mechanical engineer from the Weapons and Materials Research Directorate who heads the project team.