An Implantable Active Microport Based on a Self-Priming High-Performance Two-Stage Micropump

This paper reports on significant progress in the development of an implantable active microport system for an automated administration of aqueous drug suspensions. A novel piezoelectric two-stage micropump ensures the controlled release of minute amounts of fluid with flow rates between 0.1 mul/min and 50 mul/min. A modification of the chamber design reduces the detrimental effect of entrapped air bubbles. Due to an increased compression ratio the micropump has now a full capability to pump gas which enables a reliable self-priming. Moreover, the absence of air bubbles in the pump chamber yields a significantly enhanced accuracy of the delivered fluid volumes.