Stress-mediated growth determines division site morphology of E. Coli
Tuesday, 7.5.24, 14:15-15:15, Raum 226, Hermann-Herder-Str. 10
Bacteria are enveloped by a rigid cell wall and replicate by cell division. During the division, the cell wall needs to be drastically reshaped. It is hypothesized that the remodeling process is stress-mediated and driven by the constrictive force of a protein assembly, the Z-ring. We found that a simple large-strain morpho-elastic model can reproduce the experimentally observed shape of the division site during the constriction and septation phases of E. Coli. Our model encapsulates the multiple enzyme-dependent wall restructuring processes into a single modulus. Depending on this parameter, different experimentally known morphologies can be recovered, corresponding either to mutated or wild type cells. In addition, a plausible range\nfor the cell stiffness and turgor pressure was determined by comparing numerical simulations with experimental data on cell lysis and reported cell sacculus deformation experiments.
Physical Control of Soft Robots
Monday, 27.5.24, 14:15-15:15, Raum 226, Hermann-Herder-Str. 10
In this lecture I show that when multiple nonlinear soft actuators are interconnected they can also embody the control function, by leveraging the local negative stiffness of the actuators to drive their motion out of phase. This allows soft robots to move in pre-programmed sequence using only a single input.