My research concerns nonlinear continuum mechanics and thermodynamics, with recent emphasis on applications to problems in materials science. I have discovered that, within a macroscopic framework, additional nonclassical force systems are useful in describing phenomena associated with the material structure of a body. Two particular force systems seem applicable: (i) configurational systems associated with the kinetics of material structures such as phase interfaces, crack tips, and dislocations; (ii) microforce systems associated with macroscopic manifestations of microscopic changes. My recent research utilizes these nonclassical systems to develop general theories for phenomena such as phase transitions, fracture dynamics, atomic diffusion, and crystalline plasticity.