Abstract

The mechanical properties of living tissues are largely controlled by networks of fibres, inside the cells (cytoskeleton) as well as in the extra-cellular matrix (mostly collagen based). In this talk, I will illustrate the behaviour of these materials using two experimental systems. The first one is a model system, made of large macroscopic fibres entangled to form of light felt. It provides a convenient material to probe the mechanical behaviour of random networks. The second study is performed on in vitro collagen gels. Using either living cells or external mechanical components, we show that a local stretch induces both a strong fibre alignment and a large increase of the fibre density: this response is found to be a non-linear elastic effect.