MIT, Department of Mechanical Engineering Experience Assistant Professor, 1981–1985 Associate Professor, 1985–1991 Professor, 1991–Present Head, Mechanics & Materials Division, 1993–2001 Visiting Associate: Caltech (1990); University of New South Wales, Australia (1991); Institut Non Linéaire de Nice, France (1997); Lougborough University, England (2005) Visiting Professor: École Normale Supérieure de Cachan, France (Fall 2004)