FIGURE 1.

RMI-chip design. (A) The CAD design of the RMI-chip. A single growth channel is 36 mm long, 100 μm high, and 800 μm wide (A). The media and inoculation inlets are equipped with on-chip filters to avoid occlusions during week-long experiments. Design files are available in the online supporting materials. (B) Flow dynamics. Fluorescently labeled latex beads were used to measure media flow in the empty RMI-chip. The root entrance and the inoculation inlets were plugged with stopper pins to mimic operational flow regime of the chip. The latex beads suspended in Johnson’s were injected and the chip was imaged without and with perfusion with Johnson’s solution at 1 μL/min. The latex beads were washed from the upstream chambers and the velocity of the beads were averaged. The measured and calculated values agreed. Laminar flow was observed under the microscope.