Abstract: The disclosed technology provides a thermoplastic copolymer comprising: a plurality of difunctional triketone species; (b) a plurality of a first diamine species, wherein the first diamine species contains one or more primary amine groups and/or one or more secondary amine groups, and wherein the first diamine species does not contain a tertiary amine group; a plurality of a second diamine species, wherein the second diamine species contains one or more primary amine groups and/or one or more secondary amine groups, wherein the second diamine species does not contain a tertiary amine group, and wherein the second diamine species is different than the first diamine species; and optionally, a plurality of monofunctional amine-reactive groups. Some embodiments provide segmented thermoplastic copolymers. Methods of making and using the thermoplastic copolymer are also described, including depolymerizing the thermoplastic copolymer to form recycled monomers.

Abstract: Some variations provide a method of making a nanofunctionalized metal powder, comprising: providing metal particles containing metals selected from iron, nickel, copper, titanium, magnesium, zinc, silicon, lithium, silver, chromium, manganese, vanadium, bismuth, gallium, or lead; providing nanoparticles selected from zirconium, tantalum, niobium, or titanium; disposing the nanoparticles onto surfaces of the metal particles, in the presence of mixing media, thereby generating nanofunctionalized metal particles; and isolating and recovering the nanofunctionalized metal particles as a nanofunctionalized metal powder. Some variations provide a composition comprising a nanofunctionalized metal powder, the composition comprising metal particles and nanoparticles containing one or more elements selected from the group consisting of zirconium, tantalum, niobium, titanium, and oxides, nitrides, hydrides, carbides, or borides thereof, or combinations of the foregoing.

Abstract: Some variations provide a process for additive manufacturing of a nanofunctionalized metal alloy, comprising: providing a nanofunctionalized metal precursor containing metals and grain-refining nanoparticles; exposing a first amount of the nanofunctionalized metal precursor to an energy source for melting the precursor, thereby generating a first melt layer; solidifying the first melt layer, thereby generating a first solid layer; and repeating many times to generate a plurality of solid layers in an additive-manufacturing build direction. The additively manufactured, nanofunctionalized metal alloy has a microstructure with equiaxed grains.

Abstract: Some variations provide a magnetically anisotropic structure comprising a hexaferrite film disposed on a substrate, wherein the hexaferrite film contains a plurality of discrete and aligned magnetic hexaferrite particles, wherein the hexaferrite film is characterized by an average film thickness from about 1 micron to about 500 microns, and wherein the hexaferrite film contains less than 2 wt % organic matter. The hexaferrite film does not require a binder. Discrete particles are not sintered or annealed together because the maximum processing temperature to fabricate the structure is 500° C. or less, such as 250° C. or less. The magnetic hexaferrite particles may contain barium hexaferrite (BaFe12O19) and/or strontium hexaferrite (SrFe12O19). The hexaferrite film may be characterized by a remanence-to-saturation magnetization ratio of at least 0.7. Methods of making and using the magnetically anisotropic structure are also described.

Abstract: An antimicrobial coating is disclosed that provides fast transport rates of biocides for better effectiveness to deactivate SARS-CoV-2 and other viruses or bacteria on common surfaces. Some variations provide an antimicrobial structure comprising: a solid structural phase comprising a solid structural material; a continuous transport phase that is interspersed within the solid structural phase, wherein the continuous transport phase comprises a solid transport material; and an antimicrobial agent contained within the continuous transport phase, wherein the solid structural phase and the continuous transport phase are separated by an average phase-separation length from about 100 nanometers to about 500 microns. The antimicrobial structure is capable of destroying at least 99.99% of bacteria and/or viruses in 10 minutes of contact. Many options are disclosed for suitable materials to form the solid structural phase, the continuous transport phase, and the antimicrobial agent.

Abstract: The disclosed technology provides a vitrimeric poly(diketoenamine) network comprising: a plurality of multifunctional triketone dimers; a plurality of multifunctional amine species containing primary or secondary amine groups, but no tertiary amine groups; and optionally, one or more amine-reactive groups. The disclosed technology also provides a method of making a vitrimeric polymer network, comprising: obtaining multifunctional triketone dimers; obtaining a multifunctional imine compound, with imine groups blocking amine groups; mixing the multifunctional triketone dimers with the multifunctional imine compound, thereby forming a polymer precursor mixture; applying the polymer precursor mixture onto a substrate; and allowing the multifunctional imine compound to undergo hydrolysis with water, unblocking the amine functional groups and generating a multifunctional amine compound. The multifunctional amine compound reacts with the multifunctional triketone dimers to form a vitrimeric polymer network.

Abstract: Some variations provide a system for producing a functionalized powder, comprising: an agitated pressure vessel; first particles and second particles contained within the agitated pressure vessel; a fluid contained within the agitated pressure vessel; an exhaust line for releasing the fluid from the agitated pressure vessel; and a means for recovering a functionalized powder containing the second particles disposed onto surfaces of the first particles. A preferred fluid is carbon dioxide in liquefied or supercritical form. The carbon dioxide may be initially loaded into the pressure vessel as solid carbon dioxide. The pressure vessel may be batch or continuous and is operated under reaction conditions to functionalize the first particles with the second particles, thereby producing a functionalized powder, such as nanofunctionalized metal particles in which nanoparticles act as grain refiners for a component ultimately produced from the nanofunctionalized metal particles.

Abstract: A RF antenna comprises a quartz resonator having electrodes disposed thereon with a magnetostrictive film disposed on the quartz resonator either on, partially under or adjacent at least one of the electrodes.

Abstract: An atomic-beam source device is configured to provide a collimated beam of atoms, wherein solid-state electrochemistry is employed to recirculate atoms that are caught on collimation channel walls. The use of solid-state electrochemistry to recirculate atoms enables a chip-scale, dark-wall, high-quality collimated beam source that does not clog over time. Some variations provide an atomic-beam source device comprising: a first electrode; a second electrode that is electrically isolated from the first electrode; a first ion conductor interposed between the first electrode and the second electrode, wherein the first ion conductor is capable of transporting metal ions, and wherein the first ion conductor is in contact with the first electrode and with the second electrode; and one or more collimation channels disposed outwardly from the first ion conductor. Methods of using the atomic-beam source device are disclosed, including methods to recirculate and reuse metal atoms adsorbed on collimation channel walls.

Abstract: Some variations provide an atomic instrument configured with an optically transparent and electrochemically cleanable window, comprising: a transparent first electrode; a second electrode with an atom reservoir for first metal ions; an ion conductor interposed between the first electrode and a second electrode, wherein the ion conductor is capable of transporting second metal ions, wherein the ion conductor is in contact with the first electrode and with the second electrode, and wherein the ion conductor is optically transparent; and a transparent window support in contact with the ion conductor, wherein the electrochemically cleanable window is optically transparent, wherein the transparent window support, the ion conductor, and the first electrode collectively form a transparent and electrochemically cleanable window.

Abstract: A switched pixel array LiDAR includes a transmit optical switching network and a receive optical switching network. The transmit optical switching network is connected to a transmit antenna in each pixel of the switched pixel array, and a receive optical switching network is coupled to receive antennas in each pixel. The transmit antenna length is at least 100 times greater than the transmit antenna width. The transmit optical switching network steers a transmit beam from a laser system to the transmit antenna in a selected pixel, and emits the transmit beam through a cylindrical lens towards a target. The transmit beam is reflected off the target as a receive beam passing through the cylindrical lens towards the receive antennas in the selected pixel. The receive optical switching network transmits the receive beam to an optical receiver system which generates a receive signal configured for extraction of sensor data associated with the target.

Abstract: A low-power, chip-scale atomic beam clock is provided that maintains high precision for at least one week at any practical temperature. In some variations, the invention provides a chip-scale atomic beam clock comprising: a micro-optical bench; an atom collimator configured to generate a collimated atomic beam via differential pumping through microchannels; a VCSEL configured to emit laser photons horizontally in the plane of the micro-optical bench; an in-plane lithographically defined diffraction grating configured to split the laser photons into a first photon beam and a second photon beam; in-plane lithographically defined mirrors configured to retroflect the photon beams; in-plane photodetectors configured to detect the photon beams after being retroflected, wherein the first photon beam and the second photon beam interrogate the collimated atomic beam in-plane with the micro-optical bench.

Abstract: A drive circuit with predistortion. In some embodiments, a system includes a signal input, a predistortion circuit, and an amplifier circuit. The predistortion circuit may be operatively coupled to the signal input and to the amplifier circuit and configured to modify a radio frequency (RF) signal received at the signal input to cause the amplifier circuit to drive, into a load connected to the amplifier circuit, a current that is substantially a replica of the input signal.

Abstract: An N-bit reflectarray unit cell is disclosed comprising a first part of a first dipole and a second part of the first dipole, and a first switch for connecting and disconnecting the first part of the first dipole to and from the second part of the first dipole. The unit cell further comprises a first part of a second dipole and a second part of the second dipole, and a second switch for connecting and disconnecting the first part of the second dipole to and from the second part of the second dipole.

Abstract: This disclosure provides an improvement over the state of the art by teaching a low-cost method to produce feedstock powder, without undergoing a phase change, from industrially relevant wrought alloys that are widely available at low cost. The surfaces of aspherical particles are functionalized with particulates having a different size and composition than the particles, to control the solidification response of the feedstock. Some variations provide a metal-containing functionalized material comprising: a plurality of aspherical particles comprising a metal or a metal alloy; and a plurality of metal-containing or ceramic particulates that are assembled on surfaces of the aspherical particles, wherein the particulates are compositionally different than the aspherical particles. Methods of making and using the metal-containing functionalized materials are described.

Abstract: A local agent of a multi-agent reinforcement learning (MARL) system is disclosed, the local agent comprising a MARL network comprising at least one local hidden layer responsive to a plurality of local observations. A transmitter is configured to transmit an output of the local hidden layer to at least one remote agent, and a receiver is configured to receive an output of a remote hidden layer from the at least one remote agent. A combiner module is configured to combine the local hidden layer output with the remote hidden layer output to generate a combined hidden layer output, wherein the MARL network is configured to process the combined hidden layer output to generate at least one action value for the local agent.

Abstract: A sensor cluster is disclosed comprising a first plurality of side surfaces of a first N-hedron structure, and a second plurality of side surfaces of a second N-hedron structure. A first plurality of a first type of sensor are mounted on the first plurality of side surfaces, and a second plurality of a second type of sensor are mounted on the second plurality of side surfaces. N is greater than three and the first plurality of side surfaces are interleaved with the second plurality of side surfaces.

Abstract: A computer system comprising N real sensors for generating N real sensor signals, and a multiplexer for selecting M of the real sensor signals from the N of real sensor signals, where M is less than N. The computer system further comprises a combiner for combining the M real sensor signals to generate a virtual sensor signal representing an output of one of the unselected N real sensors.

Abstract: Some variations provide an additively manufactured article comprising a first region and a second region, wherein the first region is a solid region or a porous region, wherein the second region has a pore size larger than the first-region pore size, and wherein the first-region average permeability is lower than the second-region average permeability. Some variations provide a co-sintering method of making an architected material with regions having different permeabilities, in which different additive-manufacturing process parameters are applied to distinct regions of the structure. Other variations provide a wall-pinning method of making an architected material with regions having different permeabilities, in which additive-manufacturing process parameters are selected to sinter pinned feedstock powder between solid walls. Engineered structures with controlled permeability, integrated manifolds, and arbitrary geometries are disclosed, without the requirement of complex manufacturing.

Abstract: A corner bracket comprising a volume of matter having n pairs of parallel faces, where n is an integer larger than 2; each face of each pair of parallel faces comprising an opening; the openings in the faces of each pair of parallel faces being joined by a cylindrical recess having a longitudinal axis perpendicular to the faces joined by the cylindrical recess; the longitudinal axis of the cylindrical recesses being arranged such that the cylindrical recesses do not intersect each other. The number n can be 3 and the volume of matter can be a cube.