A rigid cylinder placed on a soft gel deforms its surface. When multiple cylinders
are placed on the surface, they interact with each other via the topography of the deformed gel
which serves as an energy landscape; as they move, the landscape changes which in turn changes
their interaction. We use a combination of experiments, simple scaling estimates and numerical
simulations to study the self-assembly of cylinders in this elastic analog of the “Cheerios Effect”,
which describes capillary interactions on a fluid interface. Our results show that the effective
two-body interaction can be well described by an exponential attraction potential as a result of
which the dynamics also show an exponential behavior with respect to the separation distance.
When many cylinders are placed on the gel, the cylinders cluster together if they are not too far
apart; otherwise their motion gets elastically arrested.