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
Institute of Soldier Nanotechnology (ISN)
Massachusetts Institute of Technology, Cambridge, MA 02139.


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.