With advances in ballistics, armies must develop better body armor. One type of modern body armor, first developed in the 1960s, is made out of advanced woven fibers that can be sewn into vests and other soft clothing. More commonly known as Dupont Kevlar®, this is one of the many body armor solutions currently employed by U.S. Forces. Another type of armor, SAPI plates, or "small arms protective insert" plates, are hardened ceramic composite plates inserted into a soldier's fragmentation protective vest in both the forward and back torso pockets.
Now, scientists are working on a new breed of armor made from magnetorheological (MR) fluids -- liquid body armor.
One type of MR fluid consists of small iron particles suspended in silicon oil. The oil prevents the particles from rusting. The fluid transforms from liquid to solid in just milliseconds when a magnetic field or electrical current is applied to it. The current causes the iron particles to lock into a uniform polarity and stack on top of each other, creating an impenetrable shield. How hard the substance becomes depends on the strength of the magnetic field or electrical current. Once the charge or magnetic field is removed, the particles unlock, and the substance goes back to a fluid state.
MR fluid will fill small pockets in the Future Force Warrior uniform fabric. The uniforms will be wired to allow an electrical current to pass through the fabric. The electrical current will be controlled by the onboard computer system and will automatically charge the MR fluid when there is a ballistic threat present.
MIT scientists who are developing the liquid body armor say that it will take five to 10 years to make the substance fully bullet resistant.