Introduction - Towards Autonomous Soft Matter Systems - page 8

Fig. 1.5 Pattern formation at various scales due to flocking of swimming fish schools, flying starlet
populations and gliding bacteria (Images taken from [ 26 - 28 ])
led to the idea of applying the ideas of scaling theories, common in statistical physics,
to the description of the collective behavior of populations of organisms [ 23 ].
There are strong motivations [ 30 - 33 ] to think that the same patterns of collective
motion apply to systems ranging from the molecular to the organismic scales. This
suggests that theremust be some (still undiscovered) governing dynamics of such sys-
tems, fromwhich the above observation follows. Naturally, observations/experiments
have to be intimately linked with theoretical modelling for better progress. Indeed,
the past few decades, have witnessed an increasing flurry of attempts to both observe
and describe flocking as well as simulate the most striking features of natural sys-
tems. Current experimental inferences, however, mainly rely on those drawn from
biological systems such as those described above. A well characterised and control-
lable self propelled object would aid greatly is testing some of the theories that are
being developed. The self propelled object should not only mimic the main features
of natural motion, but also be available in sufficient numbers to draw systematic and
statistically relevant conclusions.
In Chap. 6 , we investigate swimming at the microscale of an artificial microswim-
mer made from droplets running the BZ reaction. The interactions in this system are
purely physical i.e. hydrodynamic and therefore we probe the hydrodynamic influ-
ences on the various collective effects for such swimmers in Chap. 7 .