The design and fabrication of organ-on-a-chip (organ chip) devices play a key role in their ability to recapitulate in-vivo environments accurately. By the level of complexity, an organ chip can be single or multiple cell culture channels along with controlled physicochemical microenvironments through coupling with mechanical actuation. In addition to chip design, various flow patterns are required for microfabricated organ chips, depending on cell types, culture stage, and microphysiological experiments. In this chapter, we introduce and discuss the design parameters and microfabrication techniques of organ chips as well as various flow control schemes which are critical to creating an on-chip culture environment as well as physiologically relevant experiments. In summary, recently developed organ chip platforms are revisited, focusing on design, microfabrication, and flow control parameters.