MechE Seminar Series: Vincenzo Vitelli

Speaker: Vincenzo Vitelli

Title:Odd Elasticity

Abstract:Hooke's law states that the forces or stresses experienced by an elastic object are proportional to the applied deformations or strains. The number of coefficients of proportionality between stress and strain, i.e., the elastic moduli, is constrained by energy conservation. In this talk, we lift this restriction and generalize linear elasticity to active media with non-conservative microscopic interactions that violate mechanical reciprocity. This generalized framework, which we dub odd elasticity, reveals that two additional moduli can exist in a two-dimensional isotropic solid with active bonds. Such an odd-elastic solid can be regarded as a distributed engine: work is locally extracted, or injected, during quasi-static cycles of deformation. Using continuum equations, coarse-grained microscopic models, and numerical simulations, we uncover phenomena ranging from dislocation self-propulsion to wave propagation powered by self-sustained active elastic cycles. Besides providing insights beyond existing hydrodynamic theories of active solids, odd elasticity suggests design principles for robotic metamaterials and biological tissues.

About the Speaker:Vincenzo Vitelli is a Professor in the Physics Department at the University of Chicago. Previously he was a Professor in the Institute Lorentz in Leiden University, where he held the Chair of Condensed Matter Theory. Vitelli obtained a Bsc in theoretical physics from Imperial College London in 2000 and a Phd in Physics from Harvard University in 2006 and was a post-doctoral fellow at Upenn from 2006 till 2009.