Shear thickening fluids have a non-linear relationship between shear rate and shear stress. Schematically, it's the green line in this graph [1]. By choosing yo

Shear thickening fluids have a non-linear relationship between shear rate and shear stress. Schematically, it's the green line in this graph [1]. By choosing your material carefully, you can minimize shear stress at 'running' speeds, and then sharply ramp it up to protect against faster projectiles. [1] http://en.wikipedia.org/wiki/File:Shear_rate_vs._Shear_stress.png http://en.wikipedia.org/wiki/File:Shear_rate_vs._Shear_stres...