A parallel plate device comprising a parallel plate assembly comprising an aligned stack of n stackable plate subunits, wherein n is an integer of 2 or greater, comprising: a planar through channel bound by: a first side of a first silicon nanoporous membrane, and a first side of a second silicon nanoporous membrane, wherein the first silicon nanoporous membrane and the second silicon nanoporous membrane are positioned in a stackable frame such that the membranes are substantially parallel to each other and in a spaced apart configuration, wherein a length of a first strut of the stackable frame comprises a slot configured to form an opening at a first end of the through channel, and a length of a second strut of the stackable frame opposite the first strut comprises a slot configured to form an opening at a second end of the through channel, wherein opposite openings of the through channel define two ends of the parallel plate assembly; and a cover plate capping each outer-most stackable plate subunit of the aligned stack, and wherein a planar channel is latently formed along each of a second side of the first silicon nanoporous membrane opposite the first side, and a second side of the second silicon nanoporous membrane opposite the first side when the stackable plate subunit is stacked, wherein the parallel plate assembly comprises n + 2 of the latently formed planar channels interleaved with n planar through channels, and characterized in that the second side of the first silicon nanoporous membrane and the second side of the second silicon nanoporous membrane are each recessed from a stacking surface of the stackable frame on a corresponding side, to provide for a height of the planar channel. a planar through channel bound by: a first side of a first silicon nanoporous membrane, and a first side of a second silicon nanoporous membrane, wherein the first silicon nanoporous membrane and the second silicon nanoporous membrane are positioned in a stackable frame such that the membranes are substantially parallel to each other and in a spaced apart configuration, a first side of a first silicon nanoporous membrane, and a first side of a second silicon nanoporous membrane, wherein the first silicon nanoporous membrane and the second silicon nanoporous membrane are positioned in a stackable frame such that the membranes are substantially parallel to each other and in a spaced apart configuration, wherein a length of a first strut of the stackable frame comprises a slot configured to form an opening at a first end of the through channel, and a length of a second strut of the stackable frame opposite the first strut comprises a slot configured to form an opening at a second end of the through channel, wherein opposite openings of the through channel define two ends of the parallel plate assembly; and a cover plate capping each outer-most stackable plate subunit of the aligned stack, a length of a first strut of the stackable frame comprises a slot configured to form an opening at a first end of the through channel, and a length of a second strut of the stackable frame opposite the first strut comprises a slot configured to form an opening at a second end of the through channel, wherein opposite openings of the through channel define two ends of the parallel plate assembly; and a cover plate capping each outer-most stackable plate subunit of the aligned stack, and wherein a planar channel is latently formed along each of a second side of the first silicon nanoporous membrane opposite the first side, and a second side of the second silicon nanoporous membrane opposite the first side when the stackable plate subunit is stacked, wherein the parallel plate assembly comprises n + 2 of the latently formed planar channels interleaved with n planar through channels, and characterized in that the second side of the first silicon nanoporous membrane and the second side of the second silicon nanoporous membrane are each recessed from a stacking surface of the stackable frame on a corresponding side, to provide for a height of the planar channel. a second side of the first silicon nanoporous membrane opposite the first side, and a second side of the second silicon nanoporous membrane opposite the first side when the stackable plate subunit is stacked, wherein the parallel plate assembly comprises n + 2 of the latently formed planar channels interleaved with n planar through channels, and characterized in that the second side of the first silicon nanoporous membrane and the second side of the second silicon nanoporous membrane are each recessed from a stacking surface of the stackable frame on a corresponding side, to provide for a height of the planar channel.