Development of a multi-material micropump

Abstract

In this paper, the design of a multi-material micropump will be described. The micropump inhibits a very simple design and therefore is very cost efficient. The pump consists of one plastic part, one metal diaphragm, and three piezo lead-zirconate titanate (PZT) ceramics. The PZT ceramics, glued on a metal diaphragm, form two active valves (inlet and outlet valve) and one actuation diaphragm. The valve seats, the pump chamber, and the inlet/outlet interfacing channels are formed in the plastic body. Due to its function principle, the micropump is able to pump bidirectionally. The design of the micropump covers bubble tolerant and self-priming features. Therefore, design measures have been carried out to realize a large compression ratio and to reduce the capillary pressures of bubbles in the pump chamber. The pump is able to handle gases and liquids. The plastic body is made of poly-ether-ether-ketone, and the metal diaphragm is made of stainless steel. Therefore, a good chemical resistance will be given. First prototypes of the actuation unit have been manufactured and tested successfully. Each actuation unit is able to performa stroke ofmore than 40 μm. Furthermore, the plastic body has been realized by milling, and preliminary measurements were carried out. For future work, the development and optimization of an improved micropump using microinjection moulding instead of milling are envisaged.