**1. Introduction**

Smart control processes have been proposed for many years, while for smart flow control—especially when "smart flow control" comes at the microscale—it turns out that many new innovations and enabling technologies are possible. For instance, precise flow rate in a microreactor means high reaction efficiency. Similarly, for micromixers, smart fluid control can improve the precise distribution of every constituent. Such systems are made up of micropumps, microchannels, and microvalves, etc.

In this Special Issue on "Smart Flow Control Processes at the Microscale", 33 papers have been published, ranging from studies of flow characteristics in pumps or valves, dynamic performances in roiling mill systems or jet systems, to optimal design of special components in smart control systems. The Special Issue is available online at the following link:

https://www.mdpi.com/journal/processes/special\_issues/Flow\_Micro\_Scale.

The contributions are summarized in four parts as follows:
