Liquid fractures like a solid under stress (DST)

 Some fluid corn starch and water mixes can be fractured if hit with the right burst of air pressure.  Low impact produces a fluid response.  High impact jams grains against each other and results in fracturing and fingering as the stimulus connects.  The phenomenon can be turned on and off in liquids susceptible to Discontinuous Shear Thickening  (DST) and would have applications in soft objects that become hard only when needed as in bullet-resistant jackets and speed bumps.   More including a slow-mo video at the link.