Chemically active soft matter
We study the self-organization and transport properties of soft matter that is locally driven out of equilibrium via chemical reactions, with particular focus on the physics of living matter at the subcellular level (enzymes, biomembranes...).
Biological matter is locally driven out of equilibrium by the action of enzymes, which catalyze the chemical reactions necessary for life. The chemicals produced and consumed range from short-lived reaction intermediates, to the essential molecules involved in energy storage, cell-cell communication, etc. An important question is then: How do these nanoscale enzymes manage to self-organize in order to drive non-equilibrium activity at the right place, and at the right time?
At the level of single enzymes, we develop microscopically-detailed models to understand how enzymes transduce their catalytic action into mechanical motion, including all relevant ingredients, from hydrodynamics to thermal (and non-thermal) fluctuations. At the level of many enzymes, we use both theory as well as computer simulations to understand collective behavior. The collective phenomena that we study range from self-organization of enzymes in space (e.g. active, non-equilibrium phase separation mediated by effective long-ranged and non-reciprocal forces) to synchronization of their catalytic activity in time.
Lastly, we use continuum theories of elasticity and capillarity to study how enzymatic activity couples to 'soft', deformable cellular components such as biomembranes and membraneless organelles. Enzymatic activity can drive dynamic processes such as growth or transport (e.g. through membrane channels, membrane fusion and fission...), which in turn result in pattern formation and self-organization at length scales much larger than the nanometer length scale characteristic of enzymes.