When most people try to envision some kind of defense against projectiles, such as bullets, they probably see either a Kevlar vest or some kind of metal plate. While those can definitely serve to protect you against a bullet, they are not necessarily the optimal choice. Part of what made the discovery of Kevlar so important is that it can stop a bullet but is still so light, compared to steel armor. Now researchers at MIT and Rice University have found a way to find the next generation of light-weight bulletproof materials.
The search for polymers that can withstand high-speed projectiles has been going on for some time without an important tool, which is what these researchers have provided. That tool is a reliable way to quantify the damage done by projectiles when they impact some material. In this case the material was a composite with alternating layers, which contrast quite nicely under an electron microscope, and the projectiles were glass beads, which actually do a good job standing in for full-size bullets. After shooting the beads at the material the researchers were able to see the damage done and have already found that, for this material at least, more damage was done when it was an edge-on hit, instead of a head-on hit.
This ability to observe the damage the projectiles do is critical for developing better materials for projectile protection. Without it, researchers have to almost blindly test new materials, hoping to find something better than the last. Now they will be able to see what materials make one material better than another.