A hood assembly of a vehicle includes a hood outer panel defining an outer surface of the hood assembly, and a hood inner panel defining an inner surface of the hood assembly, such that a hood cavity is defined between the hood inner panel and the hood outer panel. An energy absorbing material is located at the hood inner panel. The energy absorbing material includes a multi-cellular structure formed from a plurality of interconnected cells having a lattice structure. Each of the plurality of interconnected cells includes at least four nodes and at least one lattice element extending between each of the at least four nodes. The at least one lattice element has a diameter no greater than 2.5 mm.