Abstract: Systems and methods described herein may produce a modified substrate. A process for producing a modified substrate may include providing a substrate that is 5 microns or less in thickness, ion tracking the substrate, and etching the tracked substrate with an etchant to produce a plurality of pores in the substrate. In some implementations, the substrate may be a polymer. In some implementations, the ion tracking may include controlling a flux of ions passing through the substrate to achieve a desired pore density. In some implementations, the track-etching of the substrate may create a 10% or more porosity in the substrate. In some implementations, the process may further include using the track-etched substrate as a support substrate for at least one of a single-layer graphene film, multi-layer graphene film, stack of graphene films, nanostructure of graphene flakes, or nanostructure of graphene platelets.

Abstract: A system for magnetic detection includes a magneto-optical defect center material including at least one magneto-optical defect center that emits an optical signal when excited by an excitation light; a radio frequency (RF) exciter system configured to provide RF excitation to the magneto-optical defect center material; an optical light source configured to direct the excitation light to the magneto-optical defect center material; and an optical detector configured to receive the optical signal emitted by the magneto-optical defect center material.

Abstract: It can be difficult to remove atomically thin films, such as graphene, graphene-based material and other two-dimensional materials, from a growth substrate and then to transfer the thin films to a secondary substrate. Tearing and conformality issues can arise during the removal and transfer processes. Processes for forming a composite structure by manipulating a two-dimensional material, such as graphene or graphene-base material, can include: providing a two-dimensional material adhered to a growth substrate; depositing a supporting layer on the two-dimensional material while the two-dimensional material is adhered to the growth substrate; and releasing the two-dimensional material from the growth substrate, the two-dimensional material remaining in contact with the supporting layer following release of the two-dimensional material from the growth substrate.

Abstract: Some embodiments comprise membranes comprising a first layer comprising a porous graphene-based material; a second layer comprising a porous graphene-based material; a channel positioned between the first layer and the second layer, wherein the channel has a tunable channel diameter; and at least one spacer substance positioned in the channel, wherein the spacer substance is responsive to the environmental stimulus. In some cases, the membranes have more than two layers of porous graphene-based material. Permeability of a membrane can be altered by exposing the membrane to an environmental stimulus. Membranes can be used in methods of water filtration, immune-isolation, timed drug release (e.g., sustained or delayed release), hemodialysis, or hemofiltration.

Abstract: A method and system for detecting a target molecule. The method includes allowing a fluid containing the target molecule to pass by a complementary moiety attached to a paramagnetic ion so as to cause the complementary moiety and the paramagnetic ion to change a position. A magnetic effect change caused by the change in position of the paramagnetic ion is detected. The target molecule is identified based on the identity of the complementary moiety and the detected magnetic effect change.

Abstract: A membrane can contain at least one substrate layer, wherein the substrate layer includes a plurality of substrate pores, and each of the substrate pores contains a plurality of nanotubes or nanowires positioned within the substrate pore. Such membranes can be incorporated into enclosures for various substances. The enclosures can be exposed to an environment, such as a biological environment (in vivo or in vitro), where the membrane can delay or not provoke an immune response from the environment. One or more substances within the enclosure can be released into the environment, one or more selected substances from the environment can enter the enclosure, one or more selected substances from the environment can be prevented from entering the enclosure, one or more selected substances can be retained within the enclosure, or combinations thereof. The enclosure can, for example, allow a sense-response paradigm to be realized.

Abstract: A two-dimensional membrane layered structure may include a support substrate layer having a plurality of substrate passages configured to allow fluid to flow therethrough, a two-dimensional membrane layer disposed on an upper surface of the support substrate layer, and a plurality of flow passages disposed between the support substrate layer and the two-dimensional membrane layer. The two-dimensional membrane layer may have a plurality of pores configured to allow fluid to flow therethrough. The plurality of pores may comprise a first portion of pores that overlap with the plurality of substrate passages and a second portion of pores that do not overlap with the plurality of substrate passages. The plurality of flow passages may be configured to allow fluid to flow through the second portion of pores to the plurality of substrate passages.

Abstract: A method and system for detecting a target molecule. The method includes allowing a fluid containing the target molecule to pass by a complementary moiety attached to a paramagnetic ion so as to cause the complementary moiety and the paramagnetic ion to change a position. A magnetic effect change caused by the change in position of the paramagnetic ion is detected. The target molecule is identified based on the identity of the complementary moiety and the detected magnetic effect change.

Abstract: A system for magnetic detection includes a magneto-optical defect center material including at least one magneto-optical defect center that emits an optical signal when excited by an excitation light; a radio frequency (RF) exciter system configured to provide RF excitation to the magneto-optical defect center material; an optical light source configured to direct the excitation light to the magneto-optical defect center material; and an optical detector configured to receive the optical signal emitted by the magneto-optical defect center material.

Abstract: A method of forming a membrane is described. A graphenic-based membrane is formed on a growth substrate, where the graphenic-based membrane have one or more layers of graphenic-based material. The graphenic-based membrane is removed from the growth substrate. A region of the graphenic-based membrane having intrinsic or native defects is identified. The region of the graphenic-based membrane is irradiated with charged particles while introducing carbonaceous material on a surface of the one or more layers of graphenic-based material to heal the intrinsic or native defects.

Abstract: Some embodiments comprise membranes comprising a first layer comprising a porous graphene-based material; a second layer comprising a porous graphene-based material; a channel positioned between the first layer and the second layer, wherein the channel has a tunable channel diameter; and at least one spacer substance positioned in the channel, wherein the spacer substance is responsive to the environmental stimulus. In some cases, the membranes have more than two layers of porous graphene-based material. Permeability of a membrane can be altered by exposing the membrane to an environmental stimulus. Membranes can be used in methods of water filtration, immune-isolation, timed drug release (e.g., sustained or delayed release), hemodialysis, or hemofiltration.

Abstract: Two-dimensional materials having apertures in their basal planes are described, where at least a portion of the apertures are occluded with a selectively introduced occluding moiety. Occluding moieties that pass into apertures function to occlude apertures. Composite membranes are described having a porous substrate with a two-dimensional material disposed on the membrane and covering only a portion of the pores, wherein at least a portion of uncovered substrate pores are occluded. Pore occlusion can be achieved by introduction of an occluding particle optionally followed by chemical reaction, deformation or swelling of the particle to facilitate occlusion of pores. Two-dimensional materials covering substrate pores can be size-selected and optionally functionalized providing for selective permeability through composite membranes. Methods for occluding defects and apertures in two-dimensional materials and for selectively occluding pores in composite membranes are provided.

Abstract: A two-dimensional membrane layered structure may include a support substrate layer having a plurality of substrate passages configured to allow fluid to flow therethrough, a two-dimensional membrane layer disposed on an upper surface of the support substrate layer, and a plurality of flow passages disposed between the support substrate layer and the two-dimensional membrane layer. The two-dimensional membrane layer may have a plurality of pores configured to allow fluid to flow therethrough. The plurality of pores may comprise a first portion of pores that overlap with the plurality of substrate passages and a second portion of pores that do not overlap with the plurality of substrate passages. The plurality of flow passages may be configured to allow fluid to flow through the second portion of pores to the plurality of substrate passages.

Abstract: Two-dimensional materials, particularly graphene-based materials, having a plurality of apertures therein can be formed into enclosures for various substances and a fibrous layer can be provided on an outside and/or on an inside of the enclosure. The enclosures can be exposed to an environment, such as a biological environment (in vivo or in vitro), where the fibrous layer can promote vascular ingrowth. One or more substances within the enclosure can be released into the environment, one or more selected substances from the environment can enter the enclosure, one or more selected substances from the environment can be prevented from entering the enclosure, one or more selected substances can be retained within the enclosure, or combinations thereof. The enclosure can, for example, allow a sense-response paradigm to be realized. The enclosure can, for example, provide immunoisolation for materials, such as living cells, retained therein.

Abstract: It is often desirable to release graphene from its growth substrate. Present graphene release techniques can damage the graphene and produce significant quantities of hazardous waste. Electrowetting techniques can be used in alternative approaches for releasing graphene from its growth substrate. Methods for releasing graphene by electrowetting can include providing a metal substrate having graphene adhered thereto, applying a dielectric layer to the graphene to form a coated structure, placing the coated structure in a liquid medium, establishing an electrical potential between the metal substrate and a conductor disposed proximate to at least a portion of the dielectric layer such that the electrical potential induces infiltration of the liquid medium between at least a portion of the metal substrate and the graphene, and releasing the graphene from the metal substrate in the presence of the infiltrated liquid medium. The electrical potential can be maintained until the graphene is released.

Abstract: It can be difficult to remove atomically thin films, such as graphene, graphene-based material and other two-dimensional materials, from a growth substrate and then to transfer the thin films to a secondary substrate. Tearing and conformality issues can arise during the removal and transfer processes. Processes for forming a composite structure by manipulating a two-dimensional material, such as graphene or graphene-base material, can include: providing a two-dimensional material adhered to a growth substrate; depositing a supporting layer on the two-dimensional material while the two-dimensional material is adhered to the growth substrate; and releasing the two-dimensional material from the growth substrate, the two-dimensional material remaining in contact with the supporting layer following release of the two-dimensional material from the growth substrate.