Introduction - Towards Autonomous Soft Matter Systems - page 2

Fig. 1.1 Center A cartoon of a cross section through a single bacterial cell. Clockwise from top The
cell membrane is primarily a lipid bilayer, acting as a scaffold for various proteins. Cytoplasmic
bacterial proteins interact with the lipid membranes to self organize, giving rise to functions such
as cell division and also a rich variety of patterns [ 1 ] Flagellar motors in the cell wall drive bacterial
motion and in a group, locomoting cells spontaneously orient in swarming clusters [ 8 ] (Figures are
adapted with permission from [ 1 , 8 , 9 ])
amounts of free energy. At the same time, chemical energy flux keeps the system
sufficiently far off equilibrium to give rise to complex dynamic function, and to main-
tain the structural components as traits of non-equilibrium steady states. Biological
cells, therefore, function as autonomous non-equilibrium soft matter systems. As a
result, a physical theory of living matter, based on the principles of soft matter and
non-equilibrium physics, seems plausible.
However, a complete description of the emergence of biological (in general, any
self-organizing system) structure and function from its microscopic components is
a long-standing and so far unsolved problem. Therefore, coarse-grained approaches
aremore suited and such approaches have led to a wealth of information about various
soft matter systems such as granular matter, colloids, emulsions, and membranes.
Similarly, significant insights into natural and model dynamical and pattern forming
systems such as aggregating amoeba populations [ 10 ], the Belousov-Zhabotinsky
reaction [ 11 ] and Rayleigh-Benard convection [ 12 ] have been possible.