For an application where a syringe must be emptied at extremely slow pace, and when pumping fluid has to be single microliters per minute or less, it may be necessary to move from traditional stepper motor with lead screw to applying a direct drive linear Piezo LEGS® motor.
What makes the Piezo LEGS® suited for the task is its ability to move smoothly at extremely slow speeds. The linear translation rate can be as low as fractions of a micrometer each second. For example, when moving at 50 nanometers per second speed, it takes ~280 hours to move a distance of 50 mm. Depending on the size and shape of the syringe, that corresponds to emptying of a 10 mL syringe at 0.5 µL per minute.