One branch of protective piezoelectric materials development. Shock armour, upon the impact of slower strikes (such as melee weapons) or the detection of imminent faster hits (bullets, for example), draws the nanomolecular bonds within the impact site tight together, hardening the area and dissipating the force of impact while resisting physical penetration of the armour.
Shock armour can be worn all over like an exomuscular suit, although sustained impacts cause the armour to repetitively seize up in struck areas, making attempts at running nearly impossible and even walking to be greatly interrupted. This tradeoff is often considered worthwhile, however, as in a pinch skin-tight shock armour is often sufficient to defend against stabbing and small arms fire, with none of the bulk of traditional armour.
Shock armour can also be implemented as a measure against high-heat attacks that deal extra damage by melting armour of materials. The forced hardening of the material means that material past its softening or even melting point can remain somewhat solid and still serve some protective end.