Ricerc@Sapienza

Swimming bacteria constantly move and consume their resources to find the best growth conditions. This continuous energy expense leads to fascinating statistical properties that do not have a counterpart in equilibrium systems. For example, a homogeneous bacterial bath can rectify the motion of asymmetric objects like ratchets. In this project, we aim to use genetically engineered E. Coli bacteria which swimming speed can be locally controlled using spatially modulated light. By arbitrarily imposing spatial gradients of cell motility, we aim to control the movement of arbitrarily shaped objects by shifting the necessary spatial asymmetry from the object to the bacterial bath. While theoretical works already validated this hypothesis, experimental pieces of evidence are still lacking. The proposed project aims to fill this gap by measuring the motion of passive objects suspended in local gradients of bacteria motility. The outcomes of this project can create new exciting frontiers toward the field of self-assembly and drug-delivery.