Marchetti has made a contribution to the development of the field of active matter, which is matter composed of self-propelled energy-consuming particles. Her research focuses on understanding the structure, phase transitions and rheology of suspensions and gels made of active matter systems like self-propelled particles, biological filaments and biological cells. Marchetti is particularly interested in understanding the behavior of cell colonies that grow in confined geometries such as those found in animal and human tissues. The bulk mechanical properties of these colonies can reveal how the cells in the tissues interact, a problem Marchetti studies theoretically.
