.Science
New Soft Helmet Turns Hard in Crash
"Researchers at the University of Hertfordshire have discovered a complex elastomeric compound they call d3o that is both soft and hard.

A shear thickening material, it is flexible when moved slowly, but when it is compresssed by an impact, its molecules lock together. The material stiffens, spreading the impact over a greater area. The Swiss company Ribcap is bringing out a new line of headgear for snowsports based on this material. The Ribcap is a combination soft, flexible beanie and tough helmet."