Nanoliter-sized liquid dispenser array for multiple biochemical analysis in microfluidic devices.

We have developed a microdispenser array made of PDMS, in which a number of nanoliter-sized droplets can be accurately dispensed and mixed with the aid of specific channels under pneumatic pressure. In this system, hydrophobic and narrow channels act as a kind of valve and help structural liquid manipulation. Also, by arranging multiple dispensers in parallel, a single injection of liquid becomes sufficient for the preparation of multiple nanoliter-sized aliquots for different reactions. We designed two kinds of microdevices for multiple liquid dispensing and mixing and evaluated their performance and reproducibility, proving them sufficient for quantitative reactions. As a practical application, biochemical analysis of glucose was performed using enzymatic reactions. This liquid dispensing technology can be widely applied in the field of microscale analysis due to its low consumption, small dead volume of reagents and samples, and ease of operation.