Here's a case in which being a gel head may actually save your life.
The British army is preparing to upgrade its standard-issue combat helmet by adding a viscous, orange gel liner designed to lock instantaneously into a solid shield when impacted by a bullet or shrapnel.
The goo, under development by Blue Divine, uses "intelligent molecules" to "shock lock" together when shot or stabbed, creating a solid pad to absorb energy (see video). The substance, called D30, returns to its "normal flexible state" after the pressure is removed.
"When moved slowly, the molecules will slip past each other, but in a high-energy impact, they will snag and lock together, becoming solid," Blue Divine CEO Richard Palmer said in an interview. "In doing so, they absorb energy."
Non-Newtonian fluids with "shear dependent viscosity," like cornstarch mixed with water, are nothing new to the scientific community.
In 2006, the U.S. Army Research Laboratory and the University of Delaware patented a fabric that combines Kevlar fibers and silica in a polyethylene glycol gel. The material remains pliable until subjected to impact, whereupon the silica nanoparticles promptly lock together, causing the blow to disperse.
The orange gel is already available in sporting goods such as ski gloves, shin guards, and equestrian equipment. The British Ministry of Defense hopes that it will soon take a load off troops by slimming down their body armor and other protective equipment.