UK defense firm BAE systems has produced a new kind of liquid body armor that is lighter, more flexible and more efficient. The new liquid armor vest has just 10 layers of kevlar with a thick viscous liquid between each layer. When a bullet impacts, the particles of the “shear-thickening” fluid lock together and thicken, forming a solid barrier and spreading the impact over a wider area. The new armor is also 45 percent thinner, allowing the wearer to move more easily.