Microfluidic devices provide an effective platform for cell culture and the study of their behavior and interactions. They can be made of various materials, among which polymers predominate, and miniaturized measuring devices are needed to monitor the processes in them. The control of process variables in microfluidic devices is much better than in large reactors, and at the same time these devices enable faster and cheaper implementation of various studies, such as studying chemotaxis and testing the effectiveness of antimicrobial agents. Various types of microorganisms can be grown in microfluidic devices, from bacteria and fungi to microalgae, and microorganisms often thrive better in them than in conventional reactors. A special type of microfluidic devices are droplet microfluidic devices, in which microorganisms are trapped in liquid droplets that act as stand-alone reactors.