ABSTRACT
A parallel nanoliter microfluidic analysis system based on capillary action, centrifugal force, and hydrophobic barriers is described. The precision of 112 parallel volume definition operations is determined to 0.75% CV at 200 nL using the individual sample introduction structure. For 20 nL, the actual measurement error is the dominating factor, with a combined error of 1.9% CV. Individual dispensing as well as dispensing through a common distribution channel is described. The volume definition precision for the common distribution channel is 1.6% CV for 200 nL. Unlike the dominating forces in microliter-sized channel systems, we describe hysteresis effects as exerting a major influence, which needs to be considered in order to control the operation and design of discrete nanoliter fluidics. Hydrophobic patches at the corners of the rectangular channel control corner-enhanced wicking. Excellent flow control of 1 and 2 nL/s is achieved using a predefined spin program.
