A novel fabrication process to realise a valveless micropump on a flexible substrate

This paper reports, for the first time, the design, fabrication and testing of a valveless micropump, entirely screen printed onto a flexible polyimide (Kapton) substrate by using sacrificial, polymer-structural and piezoelectric layers. The sacrificial layer, used to achieve a pump chamber and inlet/outlet channels, is thermally removed, analogous to a standard MEMS sacrificial process. Applying a sinusoidal AC voltage to the piezoelectric layer drives a flexible membrane which pumps liquid through the chamber. A maximum flow rate of 67 μL/min can be achieved using a drive frequency of 600 kHz.