Abstract: Apparatus, methods, and hollow metal waveguides to perform surface-enhanced Raman spectroscopy are disclosed. An example apparatus includes a hollow metal waveguide to direct Raman photons from an intermediate location within a volume of the hollow metal waveguide toward a distal end of the hollow metal waveguide, and a mirror to direct incident light from a light source to the intermediate location within the volume of the hollow metal waveguide and to direct at least some of the Raman photons toward the distal end.

Abstract: A memristive routing device includes a memristive matrix, mobile dopants moving with the memristive matrix in response to programming electrical fields and remaining stable within the memristive matrix in the absence of the programming electrical fields; and at least three electrodes surrounding the memristive matrix. A method for tuning electrical circuits with a memristive device includes measuring a circuit characteristic and applying a programming voltage to the memristive device which causes motion of dopants within the memristive device to alter the circuit characteristic. A method for increasing a switching speed of a memristive device includes drawing dopants from two geometrically separated locations into close proximity to form two conductive regions and then switching the memristive device to a conductive state by applying a programming voltage which rapidly merges the two conductive regions to form a conductive pathway between a source electrode and a drain electrode.

Abstract: A memristive device includes a first electrode and a second electrode crossing the first electrode at a non-zero angle. An active region is disposed between the first and second electrodes. The active region has defects therein. Graphene or graphite is disposed between the active region and the first electrode and/or between the active region and the second electrode.

Abstract: An optoelectronic memory cell has a transparent top electrode, a photoactive layer, a latching layer, and a bottom electrode. The photoactive layer absorbs photons transmitted through the top electrode and generates charge carriers. During light exposure, the latching layer changes its resistance under an applied electric field in response to the generation of charge carriers in the photoactive layer.

Abstract: A display matrix may have a resistance switch and a display element formed on a common display substrate. The resistance switch may have a metal insulator transition (MIT) material that has a negative differential resistance (NDR) characteristic that exhibits a discontinuous resistance.

Abstract: Chaotic oscillator-based random number generation is described. In an example, a circuit includes a negative differential resistance (NDR) device to receive an alternating current (AC) bias. The circuit further includes a capacitance in parallel with the NDR device, the capacitance having a value such that, in response to a direct current (DC) bias applied to the NDR device and the capacitance, a voltage across the capacitance oscillates with a chaotic period. The circuit further includes a random number generator to generate random numbers using samples of the voltage across the capacitance.

Abstract: A memelectronic device may have a first and a second electrode spaced apart by a plurality of materials. A first material may have a memory characteristic exhibited by the first material maintaining a magnitude of an electrically controlled physical property after discontinuing an electrical stimulus on the first material. A second material may have an auxiliary characteristic.

Abstract: Nanoscale switching devices are disclosed. The devices have a first electrode of a nanoscale width; a second electrode of a nanoscale width; and a layer of an active region disposed between and in electrical contact with the first and second electrodes. The active region contains a switching material capable of carrying a significant amount of defects which can trap and de-trap electrons under electrical bias. The switching material is in an amorphous state. A nanoscale crossbar array containing a plurality of the devices and a method for making the devices are also disclosed.

Abstract: An electroforming free memristor includes a first electrode, a second electrode spaced from the first electrode, and a switching layer positioned between the first electrode and the second electrode. The switching layer is formed of a matrix of a switching material and reactive particles that are to react with the switching material during a fabrication process of the memristor to form one or more conductance channels in the switching layer.

Abstract: A reconfigurable multilayer circuit (400) includes a complimentary metal-oxide-semiconductor (CMOS) layer (210) having control circuitry, logic gates (515), and at least two crossbar arrays (205, 420) which overlie the CMOS layer (210). The at least two crossbar arrays (205, 420) are configured by the control circuitry and form reconfigurable interconnections between the logic gates (515) within the CMOS layer (210).

Abstract: A nanoscale switching device is constructed such that an electroforming process is not needed to condition the device for normal switching operations. The switching device has an active region disposed between two electrodes. The active region has at least one switching layer formed of a switching material capable of transporting dopants under an electric field, and at least one conductive layer formed of a dopant source material containing dopants that can drift into the switching layer under an electric field. The switching layer has a thickness about 6 nm or less.

Abstract: A chemical-analysis device integrated with a metallic-nanofinger device for chemical sensing. The chemical-analysis device includes a metallic-nanofinger device, and a platform. The metallic-nanofinger device includes a substrate, and a plurality of nanofingers coupled with the substrate. A nanofinger of the plurality includes a flexible column, and a metallic cap coupled to an apex of the flexible column. At least the nanofinger and a second nanofinger of the plurality of nanofingers are to self-arrange into a close-packed configuration with at least one analyte molecule. A morphology of the metallic cap is to generate a shifted plasmonic-resonance peak associated with amplified luminescence from the analyte molecule. A method for using, and a chemical-analysis apparatus including the chemical-analysis device are also provided.

Abstract: A metal-insulator transition switching device includes a first electrode and a second electrode. A channel region which includes a bulk metal-insulator transition material separates the first electrode and the second electrode. A method for forming a metal-insulator transition switching device includes depositing a layer of bulk metal-insulator transition material in between a first electrode and a second electrode to form a channel region and forming a gate electrode operatively connected to the channel region.

Abstract: A two-dimensional array of switching devices comprises a plurality of crossbar tiles. Each crossbar tile has a plurality of row wire segments intersecting a plurality of column wire segments, and a plurality of switching devices each formed at an intersection of a row wire segment and a column wire segment. The array has a plurality of lateral latches disposed in a plane of the switching devices. Each lateral latch is linked to a first wire segment of a first crossbar tile and a second wire segment of a second crossbar tile opposing the first wire segment. The lateral latch is operable to close or open to form or break an electric connection between the first and second wire segments.

Abstract: A switching device includes at least one bottom electrode and at least one top electrode. The top electrode crosses the bottom electrode at a non-zero angle, thereby forming a junction. A metal oxide layer is established on at least one of the bottom electrode or the top electrode. A molecular layer including a monolayer of organic molecules and a source of water molecules is established in the junction. Upon introduction of a forward bias, the molecular layer facilitates a redox reaction between the electrodes, thereby reducing a tunneling gap between the electrodes.

Abstract: A metallic-nanofinger device for chemical sensing. The device includes a substrate, and a plurality of nanofingers. A nanofinger includes a flexible column, and a metallic cap coupled to an apex of the flexible column. At least the nanofinger and a second nanofinger are to self-arrange into a close-packed configuration with at least one analyte molecule disposed between at least the metallic cap and a second metallic cap of respective nanofinger and second nanofinger. A morphology of the metallic cap is to generate a shifted plasmonic-resonance peak associated with amplified luminescence from the analyte molecule. A coating encapsulating the metallic cap to respond upon exposure to a liquid, and a chemical-sensing chip including the metallic-nanofinger device are also provided.

Abstract: Transmitting nodes broadcast chirped signals on a wireless network. The transmitting nodes are time-synchronized with each other and location of the transmitting nodes is known. A receiver node detects beat frequencies created by pairs of chirped signals from different pairs of transmitting nodes. Time delay differences between chirped signals in respective beat frequency pairs are determined. The receiver node's location is determined in view of the time delay differences.

Abstract: A memristor includes a first electrode formed of a first metal, a second electrode formed of a second material, wherein the second material comprises a different material from the first metal, and a switching layer positioned between the first electrode and the second electrode. The switching layer is formed of a composition of a first material comprising the first metal and a second nonmetal material, in which the switching layer is in direct contact with the first electrode and in which at least one conduction channel is configured to be formed in the switching layer from an interaction between the first metal and the second nonmetal material.

Abstract: A stateful negative differential resistance device includes a first conductive electrode and a second conductive electrode. The device also includes a first material with a reversible, nonvolatile resistance that changes based on applied electrical energy and a second material comprising a differential resistance that is negative in a locally active region. The first material and second material are sandwiched between the first conductive electrode and second conductive electrode. A method for using a stateful NDR device includes applying programming energy to the stateful NDR device to set a state of the stateful NDR device to a predetermined state and removing electrical power from the stateful NDR device. Power-up energy is applied to the stateful NDR device such that the stateful NDR device returns to the predetermined state.

Abstract: Hydrogel compositions that include an albumin/N-acetyl cysteine solution and an aqueous suspension of calcium salts or mixture of calcium and magnesium salts are described. Also described are methods of producing and using the hydrogel compositions as a support scaffold for mineralizing connective tissue replacement and repair.