Pneumatically driven micro-dispenser for sub-micro-liter pipetting

In this study, we report a pneumatically driven micro-dispenser for precise pipetting of sub-micro-liter samples. The key feature of this micro-dispenser is the use of a suction membrane to provide a driving force for precise and quick aqueous liquid sampling and pipetting. The control of the release time of the suction membrane can generate precise pipetting of liquid volumes ranging from 0.05 µl to 0.45 µl (with 2.9% variation). Experimental results reveal that the micro-dispenser is able to perform liquid dispensing in a high reproducible manner and with a superior performance compared to commercial pipettors. This micro-dispenser is fabricated using standard soft lithography of PDMS (polydimethylsiloxane). Hence it can be easily integrated with other microfluidic devices for subsequent microfluidic applications. The developed pneumatically driven micro-dispenser is promising for further integration into micro-total-analysis systems in the field of drug dosing or for other biomedical analysis applications