Patent ID: 8381632

Claim:
A shock absorbing layer comprised of: a plurality of shock absorbing cells, where each shock absorbing cell in the plurality of shock absorbing cells is in mechanical communication with at least one other shock absorbing cell in the plurality of shock absorbing cells, and where the each shock absorbing cell in the plurality of shock absorbing cells is comprised of, a cell interior volume, a plurality of hydrogel particles contained within the cell interior volume, where the cell interior volume exceeds the volume of the plurality of hydrogel particles when the plurality of hydrogel particles are swollen, such that a free volume exists within the cell interior volume when the plurality of hydrogel particles are swollen and, a containing layer having a permeability and surrounding the cell interior volume, where the permeability is such that at least a portion of the plurality of hydrogel particles are contained within the cell interior volume when the plurality of hydrogel particles are swollen and subjected to a design shock pressure wave, and where the permeability is such that when a volume of water is adjacent to the containing layer and the volume of water is subjected to the design shock pressure wave, at least some portion of the volume of water flows through the containing layer; and a penetration resistant outer layer having a strike-face and a back-face, where the back-face is between the plurality of shock absorbing cells and the strike-face.