A composition includes hydrogel and nanoporous particles having an internal cavity without any liquid therein in an ambient condition. In another aspect, a hybrid hydrogel includes particles having vacant or liquid-free internal cavities in a first condition and allowing entry of a liquid in a second condition, to absorb impact energy. A further aspect employs particle pores into which hydrogel liquid flows when impacted. Moreover, another aspect of the present hydrogel and nanoporous particle composite is used in biomedical inserts, stretchable biometric sensors, vehicular armor, wearable helmets or armored garments, or padded vehicular interior components such as seats, headrests, instrument panels or door trim panels.
