A new micropump with bidirectional fluid transport and selfblocking effect

In this paper we present a new device which is both a forward and reverse working micropump and an active microvalve. We discuss two new mechanisms which in combination are responsible for the fluid transport of the device. The direction of the fluid transport can be switched by varying the driving frequency of the actuator. Pumps have been successfully tested with liquids and gases, showing for the first time self priming with liquids. We achieved maximum pump rates of 1600 /spl mu/l/min in forward direction and 1200 /spl mu/l/min in reverse direction by using liquids. The maximum back pressure was 17 kPa (1.7 m H/sub 2/O). Pumping air we achieved a maximum gas flow rate of 8000 /spl mu/l/min in both directions.