In this talk I will share some of my itinerary through the fields of active matter, biophysics, and optics. I will then discuss interdisciplinary connections between these fields, and ways to explore these in experiments. In the field of active matter, colloidal scientists have gradually been mastering the control and understanding of active particles. This enables us to progress towards experimental model systems at higher density and complexity. Thus, we can begin to envision active matter in the continuum: active materials. At the same time, biological systems, such as the interior of bacterial cells, can also be thought of as active materials and have at times been described as such. For instance, in some bacterial species the available energy has been associated with intracellular dynamics or with the cell’s physical state. Inspired by these observations, I will then ask: how can we use model colloidal systems to uncover basic principles of out-of-equilibrium physics, in order to elucidate biological questions? Beyond biology, can we use this knowledge to create new active materials? I will entertain this question by discussing ideas for the use of active colloidal particles in the development of optical devices with dynamical properties.