  To facilitate the use and portability of Lab on a chip technology, it is
desirable to avoid the use of bulky electronic systems for flow control.
Developed self-powered microsystems typically move only small volumes of fluid
performing up to one or two hours. We have previously shown that polymeric
micropumps combined with plastic microfluidic cartridges constitute a universal
self-powered modular microfluidic architecture suitable for moving large
volumes of fluids in short times. Herein, we show that polymeric micropumps can
provide self-powered flow control for long periods of time in the range of
hours and days. The calibration curves of various types of micropumps were
obtained including one that maintained the movement of the fluid for 23 hours,
advancing the fluid front up to 1.8 meters through a channel with a section of
0.127 mm2. We found that the actuation time of the pump was related to
degassing time, the effective surface area and the air recovery rate of the
pump. This is the first example of a long operating self-powered microsystem,
which may have a great impact in those cases where controlled flow is needed
for a long period of time and the use of electronic equipment is not desirable.
