Pedro Reis, Applied Mathematics Lab., Massachusetss Institute of Technology, U.S.A.

Elasticity and Geometry of Thin Sheets at Interfaces

LION: Time: 10:00 hrs,  De Sitterzaal – Oortgebouw

The study of the elasticity of thin objects (sheets or rods) is a rapidly burgeoning field that is bringing together seemingly separate communities ranging from (non-linear and statistical) physics through to differential geometry and nanotechnology. Recent work has shown that the strong non-linearities that arise mostly from geometry are responsible for universal modes of deformation and singularities that are not material specific. Moreover, coupling the elasticity of thin objects with other phenomena such as surface tension, adhesion at a solid interface and fracture represents a new fundamental challenge that also has numerous technological applications and finds many examples in natural processes. In this talk I shall discuss three novel problems and explore, mostly through experiments, various facets of these couplings, namely: 1) Tearing of a thin sheet from a sticky substrate, 2) Delamination of a thin sheet adhered to a soft elastic substrate and 3) Withdraw of an elastic sheet from a liquid interface: the micro-elasto pipet. These problems may a priori seem to have little in common but I will be focusing on the running similarities between the main physical ingredients involved: interaction between elastic deformations and adhesion to a solid or liquid interface.