Fig. 7. Design rule for operating multiple pico-washers in series.
a Micrograph of a device with multiple pico-washers arranged in series and labeled with key fluidic resistances: the resistance of the washing process (Rwash), with components representing the picoinjector (Rinject), and the removal process (Rremove); the resistance of the high-pressure wash stream between adjacent pico-washers (RH); and the resistance of the low-pressure waste stream between adjacent pico-washers (RL). b Circuit diagram representing the system for two pico-washers arranged in series. c Micrographs of droplets (initially laden with dye) in devices with multiple pico-washers in which the design rule is not satisfied. d Micrographs of droplets (initially laden with dye) in devices with pico-washers in which the design rule is satisfied. All scale bars represent 50 μm