Biological & Soft Matter Seminar: Flagello – a gel made of bacterial flagella
Itamar Kolvin University of California, Santa Barbara
Assembling trusses out of rods is a generic route to create mechanically stable spatially open structures. Polymer gels, metal foams and the cytoskeleton are mechanical networks that follow this paradigm to generate stiffness. It is, however, challenging to predict network stiffness from first principles. I will describe how we construct mechanical networks out of bacterial flagella. Flagella are rigid helical filaments that can both stretch and bend. By covalently cross-linking flagella, we form ultra-soft gels whose elasticity is virtually rate independent. Gel elasticity is tuned at the particle level by using flagella mutants of variable helicity. Flagella gels are therefore a promising model system for studying rigidity transitions in mechanical networks.