  We study the dynamics of front solutions in a certain class of
multi-component reaction-diffusion systems, where one fast component governed
by an Allen-Cahn equation is weakly coupled to a system of $N$ linear slow
reaction-diffusion equations. By using geometric singular perturbation theory,
Evans function analysis and center manifold reduction, we demonstrate that and
how the complexity of the front motion can be controlled by the choice of
coupling function and the dimension $N$ of the slow part of the multi-component
reaction-diffusion system. On the one hand, we show how to imprint and unfold a
given scalar singularity structure. On the other hand, for $N\geq 3$ we show
how chaotic behaviour of the front speed arises from the unfolding of a
nilpotent singularity via the breaking of a Shil'nikov homoclinic orbit. The
rigorous analysis is complemented by a numerical study that is heavily guided
by our analytic findings.
