Research interests Intracellular transport Inside cells, molecular motors attached to microtubules transport various loads (the cargos) from one to another location. In many cases, different species of motors move in opposite directions on the same microtubules. They can detach from one microtubule and connect to another one. We want to understand how these motors organize themselves in order to have efficient transport. In the PHd thesis (2008-2011) of Max Ebbinghaus, which was a joint thesis between the University of Saarland (with L. Santen), and the University Paris-Sud, we have shown that the dynamics of the underlying network could produce a transition between a jammed state (static lattice) and an efficient regime in which the network dynamics prevents jam formation. In her PHd thesis (2013-2015) which was a joint thesis between the University of Saarland (with L. Santen), and the University Paris-Sud, Sarah Klein studied the intracellular transport of cargos by multiple teams of motors. Some non trivial effects in the displacement of the cargo were predicted. Indeed, while common sense would predict a slowing down of the cargo when the viscosity of the surrounding medium increases, this is actually not the case due to the asymmetry between the teams. An increase of viscosity can speed up the cargo or even reverse its direction of motion. A similar effect was predicted when ATP concentration is varied. In another collaboration with I. Weber, L. Santen and G. Schehr, we are studying the fluctuations of microtubules under the forces exerted by molecular motors.