Serial-to-parallel interfaces for efficient sample transfer on microfluidic devices.

We report serial-to-parallel interfaces for rapidly and efficiently transferring samples from a single microfluidic channel to multiple parallel channels. Three designs and operation modes were evaluated to determine the most efficient transfer process. All designs employed two routing channels to direct the sample into the parallel channels and to prevent sample from leaking into adjacent channels. For two of the three designs, a tee valve and gated valve were added to the interface prior to routing the samples to assist with sample injections into the parallel channels. Injection times as short as 20 ms and injection frequencies up to 10 Hz were achieved with relative standard deviations less than 0.5% for the injected area. With an injection time of 50 ms and injection frequency of 10 Hz, up to 50% of the sample is efficiently transferred. Among the three designs, the interface with the gated valve provided the highest performance and reproducibility.