Design, fabrication and performance evaluation of a printed-circuit-board microfluidic electrolytic pump for lab-on-a-chip devices

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>We report <I>for the first time</I> an electrolytic micropump based on an electrode chip fabricated on a printed circuit board (PCB), and compare its performance with that of a micropump based on an electrode chip fabricated using conventional microfabrication. Gold interdigitated (IDT) electrodes are patterned on a PCB to minimize ohmic loss during electrolysis. Custom-built acrylic fixtures are used to characterize pumping performance of various electrode chips with different electrode shapes and materials. Hydrogen and oxygen gas bubbles produced by electrolysis generate liquid flow inside a microchannel. As predicted by the theory of water electrolysis, the micropump produces flow rate increasing linearly with current at a wide range (1 mA–2 A). Our micropump yields the maximum flow rate of 31.6 ml/min and maximum backpressure of 547 kPa (at 34 μl/min), significantly high compared with the previous micropumps based on various actuation mechanisms including piezoelectric actuation, electroosmosis and phase change. The PCB-based micropump with a thick electroplated-gold electrode (0.43 μm) chip shows the overall best performance in terms of flow generation, power consumption and cost, compared with the PCB-based pump using an thin electroless-gold electrode (0.04 μm) and the pump using a microfabricated chip with a sputtered gold electrode (0.2 μm). We anticipate the PCB-based electrolysis pump will be used in portable lab-on-a-chip devices where an integrated microscale pressure source with low power consumption and simple fabrication is crucial.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An electrolytic micropump based on PCB technology for portable lab-on-a-chip devices is designed, fabricated and characterized. </LI> <LI> A theoretical model for pump power consumption as a function of electrode geometry is proposed and experimentally verified. </LI> <LI> Flow rate and backpressure of the micropump are measured as a function of current using custom-built jigs and experimental setups. </LI> <LI> Performance of our micropumps is thoroughly compared with that of the micropump made using conventional microfabrication. </LI> <LI> Our PCB micropump with electroplated gold electrode yields exceptionally high flow rate up to 31.6 ml/min and backpressure up to 547 kPa. </LI> </UL> </P>