Abstract: Novel fluid logic devices are disclosed. Certain examples of the fluid logic devices include two or more fluid logic gates that are each operative to select and/or direct analytes in a sample into one or more fluid flow channels in communication with the fluid logic gates. The fluid logic device can be part of a larger system, such as a chromatography system, or can be stand-alone device.

Abstract: A bulk fluid flow gate is provided. In accordance with certain exemplary embodiments the bulk fluid flow gate includes a first and second entry port and first and second exit ports. Bulk fluid is flowed into the chamber to provide greater hydrodynamic resistance at the first exit port than at the second exit port. The bulk fluid flow gate is useful for separation, testing and or analysis of analytes. Methods of making and using the bulk fluid flow gate are also provided. In accordance with certain exemplary embodiments a fluid flow gate includes a first entry port to a microscale chamber and first and second exit ports. In accordance with certain exemplary embodiments a fluid flow gate includes a first entry port to a chamber and first and second exit ports, wherein greater hydrodynamic resistance is provided at the first exit port than at the second exit port.