A valve-less diffuser micropump for microfluidic analytical systems

The suitability of valve-less micropumps in biochemistry has been shown. Fl uids encountered in various biochemical methods that are problematic for ot her micropumps have been pumped with good performance. The pump is fabricat ed as a silicon-glass stack with a new process involving three subsequent d eep reactive ion etching steps. Some of the main advantages of the valve-le ss diffuser pump are the absence of moving parts (excluding the pump diaphr agm), the uncomplicated planar design, and high pump performance in terms o f pressure head and flow rare. In addition, the micropump is self-priming a nd insensitive to particles and bubbles present in the pumped media. The re sults show that the valve-less micropump successfully pumps fluids within t he viscosity range of 0.001-0.9 N s/m(2). The micropump is not sensitive to the density, ionic strength, or pH of the pumped media. Effective pumping of solutions containing beads of different sizes was also demonstrated. Liv ing cells were pumped without inducing cell damage and no cell adhesion wit hin the pump chamber was found. No valve-less micropump has previously been reported to pump such a wide variety of fluids. (C) 2001 Elsevier Science B.V. All rights reserved.