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Comprehensive gas chromatography (GC × GC) is gaining popularity for the analysis of complex mixtures.The technique has applicability for class determinations, target analyte analysis, pattern recognition, and others.The practice of GC × GC is commonly done using thermal modulators that have a sub-ambient cryo/hot zone between the primary and secondary column.While these designs work well, they require the use of large amounts of cryogen.A simpler modulation concept developed by Seeley combines a fluidic switch design with high differential flow to mnsfer primary columm effluent to the secondary column in a very narrow pulse, providing the required fast separation in the second dimension.[1] This concept has been incorporated into a unique low mass metal structure where complex flow channels are produced using photolithographic chemical milling for low dead volume and precise dimensions.The modulator then consists of a planar structure where flow tees and collector channel are all incorporated internally to the device.All external connections are made through CPM fitting incorporated into the structure for near-zero unswept volumes and leak proof seals.The entire structure is then deactivated.