Abstract: The glass transition is a dynamical state change from a liquid state to a kinetically arrested amorphous phase that is achieved by super-cooling or increasing the density of its constituents.The dynamical slowdown, high viscosity, fragility, and dynamical heterogeneity are some of the key signatures of glass transition. Such transitions are popular in plethora of soft matter systems viz. colloid,polymer and foams [1]. In recent times the glass transition has become popular in active systems too (comprising of driven or active constituents), e.g.,ing tissues [2,3]. In this se minar, I will present our recent experimental results that demonstrate the realization of glass transition in the dense population of motile bacteria that grows in a controlled environmental condition [4]. We have shown that the vitrification of bacterial population occurs in two-step viz. orientation glass-transition followed by a translation glass transition.
Reference:
1. L. Berthier and G. Biroli, Theoretical perspective on the glass transition and amorphous materials, Rev. Mod. Phys. 83, 587 (2011).
2. M. C. Marchetti, J. F. Joanny, S. Ramaswamy, T. B. Liverpool, J. Prost, M. Rao, and R. A. Simha, Hydrodynamics of soft active matter, Rev. Mod. Phys. 85, 1143 (2013).
3. Elsen Tjhung and Ludovic Berthier, Analogies between growing dense active matter and soft driven glasses, Phys. Rev. Research, 2, 043334 (2020).
4. Hisay Lama, Masahiro Yamamoto, Yujiro Furuta, Takuro Shimaya and Kazumasa A. Takeuchi, Emergence of bacterial glass: two-step glass transition in 2D bacterial suspension, arXiv (2022), doi:10.48550/arXiv.2205.10436.