Fabrication of Liquid-Filled Voronoi Foams for Impact Absorption Using Material Jetting Technology

An important consideration in the design of any mechanical system is its ability to isolate and dissipate vibrational and impact energy. Closed-cell foams utilize cell crumpling to absorb energy, relying solely on viscoelastic effects for damping. Liquids, however, can generate large amounts of damping from fluid channel friction and turbulence. We produced closed-cell foams that are liquid filled, resulting in tunable materials that absorb energy better than either component on their own, using a Voronoi generation model and a J750 printer that could jet curable and incurable liquids. We found that by changing the wall thickness and liquid percentage, we achieve a stiffness range of 4.1 N/mm to 80 N/mm. Our work introduces this new class of damping metamaterial that can absorb tunable amounts of energy per unit volume. These impact-absorbing structures may benefit applications such as protective equipment, healthcare, and automotive industries.