Light carries energy and momentum. It can therefore alter
the motion
of objects on the atomic to astronomical scales. Being widely available,
readily controllable, and broadly biocompatible, light is also an
ideal tool to propel microscopic particles, drive them out of thermodynamic
equilibrium, and make them active. Thus, light-driven particles have
become a recent focus of research in the field of soft active matter.
In this Perspective, we discuss recent advances in the control of
soft active matter with light, which has mainly been achieved using
light intensity. We also highlight some first attempts to utilize
light’s additional properties, such as its wavelength, polarization,
and momentum. We then argue that fully exploiting light with all of
its properties will play a critical role in increasing the level of
control over the actuation of active matter as well as the flow of
light itself through it. This enabling step will advance the design
of soft active matter systems, their functionalities, and their transfer
toward technological applications.