Adaptive energy-absorbing materials using field-responsive fluid-impregnated cellular solids Suraj S. Deshmukh and G.H. McKinley Hatsopoulos Microfluids Laboratory, Department of Mechanical Engineering and Institute of Soldier Nanotechnology (ISN) Massachusetts Institute of Technology, Cambridge, MA 02139. Abstract: Materials with rapidly-controllable and switchable energy-absorption and stiffness properties that conform to the external environment have been developed, characterized and modeled. These ‘smart’ materials are fluid-solid composites resulting from impregnation of a field-responsive fluid, such as a magnetorheological fluid or a shear-thickening fluid, in a cellular solid. The total energy absorbed by these materials can be modulated by a factor of 50-fold for small volume fractions of the fluid (~15%) using magnetic fields varying from 0 to 0.2 Tesla. A scaling model is proposed for the fluid-solid composite that collapses experimental data onto a single master curve. This class of material has application potential in devices such as impact absorbing headrests and cushioned impact assemblies. |