  In this review we discuss recent advances in the self-assembly of
self-propelled colloidal particles and highlight some of the most exciting
results in this field with a specific focus on dry active matter. We explore
this phenomenology through the lens of the complexity of the colloidal building
blocks. We begin by considering the behavior of isotropic spherical particles.
We then discuss the case of amphiphilic and dipolar Janus particles. Finally,
we show how the geometry of the colloids and/or the directionality of their
interactions can be used to control the physical properties of the assembled
active aggregates, and suggest possible strategies on how to exploit activity
as a tunable driving force for self-assembly. The unique properties of active
colloids lend promise for the design of the next generation of functional,
environment-sensing microstructures able to perform specific tasks in an
autonomous and targeted manner.
