Abstract: Nanomaterial epidermal sensors can be adhered to the skin and worn comfortably and inconspicuously for days to allow for repeated biometric sensing. The nanomaterial epidermal sensors may be comprised of a monolayer of graphene coating a flexible polymer substrate. Various nanomaterial epidermal sensors may be quickly fabricated using a cost-efficient “cut-and-paste” method on transfer paper and can be adhered directly to skin without tape or adhesive, much like a temporary-tattoo. The nanomaterial epidermal sensors may be optically transparent and may be used to measure an electrocardiogram (ECG), an electroencephalogram (EEG) or an electromyogram (EMG) with a signal-to-noise ratio that is comparable to conventional electrodes. In addition, the nanomaterial epidermal sensors may be used to measure other parameters, such as skin temperature or skin hydration.

Abstract: The present disclosure provides a 2-dimensional (2D) non-volatile switch (2DNS), with a vertical metal-insulator-metal (MIM) structure that includes a semiconducting monolayer crystalline non-metallic atomic sheet sandwiched between a top metal electrode and a bottom metal electrode. The 2DNS is able to perform stable non-volatile resistance switching, including both unipolar and bipolar switching, with a high ON/OFF ratio, low ON resistance, and low operating voltage. The monolayer atomic sheet may include hexagonal boron nitride (h-BN) or a transition metal dichalcogenide (TMD), such as MoS2, MoSe2, WS2, or WSe2. The present disclosure also provides methods for synthesizing a semiconducting monolayer crystalline non-metallic atomic sheet on a target substrate. The monolayer atomic sheet may include h-BN or a TMD, such as MoS2, MoSe2, WS2, or WSe2.

Abstract: Nanomaterial epidermal sensors can be adhered to the skin and worn comfortably and inconspicuously for days to allow for repeated biometric sensing. The nanomaterial epidermal sensors may be comprised of a monolayer of graphene coating a flexible polymer substrate. Various nanomaterial epidermal sensors may be quickly fabricated using a cost-efficient “cut-and-paste” method on transfer paper and can be adhered directly to skin without tape or adhesive, much like a temporary-tattoo. The nanomaterial epidermal sensors may be optically transparent and may be used to measure an electrocardiogram (ECG), an electroencephalogram (EEG) or an electromyogram (EMG) with a signal-to-noise ratio that is comparable to conventional electrodes. In addition, the nanomaterial epidermal sensors may be used to measure other parameters, such as skin temperature or skin hydration.

Abstract: A field-effect transistor and method for fabricating such a field-effect transistor that utilizes an air-sensitive two-dimensional material (e.g., silicene). A film of air-sensitive two-dimensional material is deposited on a crystalized metallic (e.g., Ag) thin film on a substrate (e.g., mica substrate). A capping layer of insulating material (e.g., aluminum oxide) is deposited on the air-sensitive two-dimensional material. The substrate is detached from the metallic thin film/air-sensitive two-dimensional material/insulating material stack structure. The metallic thin film/air-sensitive two-dimensional material/insulating material stack structure is then flipped. The flipped metallic thin film/air-sensitive two-dimensional material/insulating material stack structure is attached to a device substrate followed by having the metallic thin film etched to form contact electrodes. In this manner, the pristine properties of air-sensitive two-dimensional materials are preserved from degradation when exposed to air.

Abstract: The integration of monolayer graphene with a semiconductor device for gas sensing applications involves obtaining a CMOS device that is prepared to receive monolayer graphene channels. After population of the monolayer graphene channels on the CMOS device, electrical contacts are formed at each end of the monolayer graphene channels with interconnect vias having sidewalls angled at less then 90°. Additional metallization pads are added at the location of the monolayer graphene channels to improve planarity and reliability of the semiconductor processing involved.

Abstract: The sensitivity of a graphene gas sensor to a gas analyte molecule may be significantly enhanced using molecular doping, which may be as effective as substitutional doping and more effective than electric-field doping. In particular, the room temperature sensitivity of NO2-doped graphene to NH3 was measured to be comparable to the sensitivity of graphene doped with substitutional boron atoms and superior to that of undoped graphene by an order of magnitude. The detection limit for NO2-doped graphene gas sensors was estimated to be about 200 ppb, which may be improved with extended exposure to NO2, compared to a detection limit of about 1.4 ppm for undoped graphene. While the stability analysis of NO2-doped graphene sensors indicates that the doping method may not be completely stable, molecular doping is nevertheless a candidate technique for sensitivity improvement by enhancing the initial carrier concentration.

Abstract: A field-effect transistor and method for fabricating such a field-effect transistor that utilizes an air-sensitive two-dimensional material (e.g., silicene). A film of air-sensitive two-dimensional material is deposited on a crystalized metallic (e.g., Ag) thin film on a substrate (e.g., mica substrate). A capping layer of insulating material (e.g., aluminum oxide) is deposited on the air-sensitive two-dimensional material. The substrate is detached from the metallic thin film/air-sensitive two-dimensional material/insulating material stack structure. The metallic thin film/air-sensitive two-dimensional material/insulating material stack structure is then flipped. The flipped metallic thin film/air-sensitive two-dimensional material/insulating material stack structure is attached to a device substrate followed by having the metallic thin film etched to form contact electrodes. In this manner, the pristine properties of air-sensitive two-dimensional materials are preserved from degradation when exposed to air.

Abstract: The integration of monolayer graphene with a semiconductor device for gas sensing applications involves obtaining a CMOS device that is prepared to receive monolayer graphene channels. After population of the monolayer graphene channels on the CMOS device, electrical contacts are formed at each end of the monolayer graphene channels with interconnect vias having sidewalls angled at less then 90°. Additional metallization pads are added at the location of the monolayer graphene channels to improve planarity and reliability of the semiconductor processing involved.

Abstract: The sensitivity of a graphene gas sensor to a gas analyte molecule may be significantly enhanced using molecular doping, which may be as effective as substitutional doping and more effective than electric-field doping. In particular, the room temperature sensitivity of NO2-doped graphene to NH3 was measured to be comparable to the sensitivity of graphene doped with substitutional boron atoms and superior to that of undoped graphene by an order of magnitude. The detection limit for NO2-doped graphene gas sensors was estimated to be about 200 ppb, which may be improved with extended exposure to NO2, compared to a detection limit of about 1.4 ppm for undoped graphene. While the stability analysis of NO2-doped graphene sensors indicates that the doping method may not be completely stable, molecular doping is nevertheless a candidate technique for sensitivity improvement by enhancing the initial carrier concentration.

Abstract: A field-effect transistor and method for fabricating such a field-effect transistor that utilizes an air-sensitive two-dimensional material (e.g., silicene). A film of air-sensitive two-dimensional material is deposited on a crystallized metallic (e.g., Ag) thin film on a substrate (e.g., mica substrate). A capping layer of insulating material (e.g., aluminum oxide) is deposited on the air-sensitive two-dimensional material. The substrate is detached from the metallic thin film/air-sensitive two-dimensional material/insulating material stack structure. The metallic thin film/air-sensitive two-dimensional material/insulating material stack structure is then flipped. The flipped metallic thin film/air-sensitive two-dimensional material/insulating material stack structure is attached to a device substrate followed by having the metallic thin film etched to form contact electrodes.

Abstract: The electrical properties of graphene and molybdenum sulfide semiconductor devices are improved by incorporating a fluoropolymer capping layer that is in contact with the graphene or molybdenum sulfide layer.

Abstract: Wire bonds connect current-carrying edges of high-frequency planar conductors to other electrical devices. In one embodiment, planar transmission lines are interconnected using two wire bonds. One bond wire extends from an edge of a first center conductor to a corresponding edge of a second center conductor, and a second bond wire extends from the other edge of the first center conductor to the other edge of the second center conductor. Embodiments include center conductors at different heights and having different widths, and different electrical devices, such as semiconductor integrated circuits. In a particular embodiment, ball bonding is used. In some embodiments, a tack bond is included after a ball bond to allow closer attachment of the bond wire to the edge of the conductor.

Abstract: Wire bonds connect current-carrying edges of high-frequency planar conductors to other electrical devices. In one embodiment, planar transmission lines are interconnected using two wire bonds. One bond wire extends from an edge of a first center conductor to a corresponding edge of a second center conductor, and a second bond wire extends from the other edge of the first center conductor to the other edge of the second center conductor. Embodiments include center conductors at different heights and having different widths, and different electrical devices, such as semiconductor integrated circuits. In a particular embodiment, ball bonding is used. In some embodiments, a tack bond is included after a ball bond to allow closer attachment of the bond wire to the edge of the conductor.