Pressure-driven fluidic system to control, multiplex and recirculate cell culture medium for Organs-on-Chips

Organ-on-Chip (OoC) devices are increasingly used to mimic the tissue microenvironment of cells in intact organs. This includes microchannels to mimic, for example, fluidic flow through vessels. Present methods for controlling microfluidic flow in these systems rely on gravity, rocker systems or external pressure pumps. For many purposes, pressure pumps give the most consistent flow profiles but they are not well-suited for high throughput as might be required for testing drug responses. Here, we describe a method which allows multiplexing of microfluidic channels in OoC devices plus the accompanying custom software necessary to run the system. Moreover, we show the approach is also suited to for recirculation of culture medium, an essential cost consideration when expensive culture reagents are used that are not "spent" through uptake by the cells during transient unidirectional flow.