Abstract: A nanofluid contact potential difference cell includes a cathode with a lower work function and an anode with a higher work function separated by a nanometer-scale spaced inter-electrode gap containing a nanofluid with intermediate work function nanoparticle clusters. The cathode comprises a refractory layer and a thin film of electrosprayed dipole nanoparticle clusters partially covering a surface of the refractory layer. A thermal power source, placed in thermal contact with the cathode, to drive an electrical current through an electrical circuit connecting the cathode and anode with an external electrical load in between. A switch is configured to intermittently connect the anode and the cathode to maintain non-equilibrium between a first current from the cathode to the anode and a second current from the anode to the cathode.

Abstract: Embodiments relate to systems designed for thermal transfer augmentation and thermionic energy harvesting. Thermionic energy harvesters are configured to supply electricity for applications such as electronics, communications, and other electrical devices. Thermal transfer may be used for a variety of heating/cooling and power generation/heat recovery systems, such as, refrigeration, air conditioning, electronics cooling, industrial temperature control, waste heat recovery, off-grid and mobile refrigeration, and cold storage.

Abstract: An embodiment relates to an apparatus including first, second, and third electrodes and first and second transport media. The first electrode includes opposite first and second surfaces having first and second work function values, respectively. The second electrode includes a third surface facing the first surface and having a third work function value. The third electrode includes a fourth surface facing the second surface and having a fourth work function value. The third and fourth work function values are different than the first and second work function values. The third electrode is electrically coupled to the second electrode. The first transport medium is positioned between the first electrode and the second electrode and includes first nanoparticles. The second transport medium is positioned between the first electrode and the third electrode and includes second nanoparticles. In embodiments, the apparatus is coupled to an electrical load to power the load.

Abstract: An embodiment relates to an apparatus including first, second, and third electrodes and first and second transport media. The first electrode includes opposite first and second surfaces having first and second work function values, respectively. The second electrode includes a third surface facing the first surface and having a third work function value. The third electrode includes a fourth surface facing the second surface and having a fourth work function value. The third and fourth work function values are different than the first and second work function values. The third electrode is electrically coupled to the second electrode. The first transport medium is positioned between the first electrode and the second electrode and includes first nanoparticles. The second transport medium is positioned between the first electrode and the third electrode and includes second nanoparticles.

Abstract: Embodiments relate to an apparatus that includes an electronics layer with at least one electronic component, and a thermal energy harvesting thermionic device to receive thermal energy and generate an electrical output for powering the electronic component. The thermionic device includes a cathode, an anode spaced from the cathode, and a plurality of nanoparticles in at least one medium contained between the cathode and the anode to permit electron transfer between the cathode and the anode. An intermediate layer is positioned between the thermionic device and the electronics layer. The intermediate layer is made of a gradient thermal expansion material (TEM). Related systems and methods are also provided.

Abstract: A nanofluid contact potential difference cell includes a cathode with a lower work function and an anode with a higher work function separated by a nanometer-scale spaced inter-electrode gap containing a nanofluid with intermediate work function nanoparticle clusters. The cathode comprises a refractory layer and a thin film of electrosprayed dipole nanoparticle clusters partially covering a surface of the refractory layer. A thermal power source, placed in thermal contact with the cathode, to drive an electrical current through an electrical circuit connecting the cathode and anode with an external electrical load in between. A switch is configured to intermittently connect the anode and the cathode to maintain non-equilibrium between a first current from the cathode to the anode and a second current from the anode to the cathode.

Abstract: Embodiments relate to methods of manufacturing and operating nano-scale energy converters and electric power generators. The nano-scale energy converters include two electrodes separated a predetermined distance. The first electrode is manufactured to have a first work function value. The second electrode is manufactured to have a second work function value different from the first work function value. A cavity is formed between the first and second electrodes, and a nanofluid is disposed in the cavity. The nanofluid includes a plurality of nanoparticles.

Abstract: Embodiments relate to an apparatus including an appliance adapted to generate thermal energy, a thermal energy harvesting thermionic device proximal to the appliance to receive the thermal energy from the appliance and generate an electrical output, an electrical conductive path configured to transfer electrical output from the thermal energy harvesting thermionic device to a load, and a heat dissipating device positioned with respect to the thermal energy harvesting thermionic device to reduce a temperature of the electrical conductive path by thermal exchange. The thermal energy harvesting thermionic device includes a cathode, an anode spaced from the cathode, and a plurality of nanoparticles in a medium contained in the space between the cathode and the anode. The nanoparticles are configured to permit electron transfer between the cathode and the anode.

Abstract: A nanofluid contact potential difference cell comprises a cathode with a lower work function and an anode with a higher work function separated by a nanometer-scale spaced inter-electrode gap containing a nanofluid with intermediate work function nanoparticle clusters. The cathode comprises a refractory layer and a thin film of electrosprayed dipole nanoparticle clusters partially covering a surface of the refractory layer. A thermal power source, placed in good thermal contact with the cathode, drives an electrical current through an electrical circuit connecting the cathode and anode with an external electrical load in between. A switch is configured to intermittently connect the anode and the cathode to maintain non-equilibrium between a first current from the cathode to the anode and a second current from the anode to the cathode.

Abstract: Embodiments relate to methods of manufacturing and operating nano-scale energy converters and electric power generators. The nano-scale energy converters include two electrodes separated a predetermined distance. The first electrode is manufactured to have a first work function value. The second electrode is manufactured to have a second work function value different from the first work function value. A cavity is formed between the first and second electrodes, and a nanofluid is disposed in the cavity. The nanofluid includes a plurality of nanoparticles, with the nanoparticles having a third work function value that is greater than the first and second work function values. The relationship of the work function values of the nanoparticles to the work function values of the electrodes optimizes transfer of electrons to the nanoparticles through Brownian motion and electron hopping.

Abstract: Embodiments relate to an apparatus including a transport medium, a first surface, and a second surface. The transport medium includes a nanoparticle suspended in a dielectric, and has a first side and a second side. The first side opposes the second side. The nanoparticle includes a conductive metal at least partially covered by a monolayer film that is less conductive than the conductive metal. The first surface is disposed at the first side of the transport medium and has a first work function. The second surface is disposed at the second side of the transport medium and has a second work function. The first work function is lower than the second work function. In embodiments, the apparatus is configured to power a load coupled to the apparatus.

Abstract: Embodiments relate to a method in which electrical energy is supplied to a heat generating source to convert the electrical energy to heat. A thermal energy harvesting thermionic device proximal to the heat generating source to receive the heat from the heat generating source is heated and an electrical output is generated. The thermal energy harvesting thermionic device includes at least a cathode, an anode spaced from the cathode to provide an inter-electrode gap between the cathode and the anode, and a plurality of nanoparticles suspended in a fluid medium contained in the inter-electrode gap. The temperature of the thermal energy harvesting thermionic device is monitored, and a source of the electrical energy is activated to supply the electrical energy to the heat generating source in response to a change in the temperature of the thermal energy harvesting thermionic device. Also provided are related apparatus.

Abstract: Embodiments relate to an apparatus for a nano-scale energy converter and an electric power generator. The apparatus includes two electrodes separated by a distance. The first electrode is manufactured to have a first work function value and the second electrode is manufactured to have a second work function value, with the first and second work function values being different. A cavity is formed by the distance between the first and second electrodes, and a nanofluid is disposed in the cavity. The nanofluid includes nanoparticles suspended in a dielectric medium. The nanoparticles have a third work function value that is greater than the first and second work function values. The relationship of the work function values of the nanoparticles to the work function values of the electrodes optimizes the transfer of electrons to the nanoparticles through Brownian motion and electron hopping.

Abstract: A method for fabricating a single electron transistor is provided. A substrate includes a substantially planar surface with a source electrode, a drain electrode, and a gate electrode thereon, with the source and drain electrodes spaced apart from one another by a gap. The source electrode and the drain electrode are electrified, and a single nanometer-scale conductive particle is electrospray deposited in the gap. The single nanometer-scale conductive particle has an effective size of not greater than 10 nanometers. At least one carbon nanotube is deposited on the substrate and subjected to dielectrophoresis to position the carbon nanotube within 1 nanometer of the single nanometer-scale conductive particle. The at least one carbon nanotube establishes a first connection between the source electrode and the single nanometer-scale conductive particle and a second connection between the drain electrode and the single nanometer-scale conductive particle.

Abstract: Embodiments relate to a flight vehicle structural component for nano-scale energy converters and thermionic power harvesting devices. The apparatus includes a first electrode, a second electrode spaced from the first electrode to provide an inter-electrode gap between the first and second electrodes, and a plurality of nanoparticles suspended in a medium contained in the inter-electrode gap, the nanoparticles arranged in the inter-electrode gap to permit electron transfer between the first electrode and the second electrode. The flight vehicle structural component is operable as an energy harvesting device and configured to define a skin, a portion of the skin, a structural support, or a portion of the structural support of a flight vehicle.

Abstract: Embodiments relate to a method of manufacturing pinned nano-structures with tailored gradient properties. First and second compositions are provided, Each of the compositions includes a nano-structural material, a plurality of grain growth inhibitor nano-particles, and at least one of a tailoring solute and a plurality of tailoring nano-particles. Deposition layers are formed proximal to a substrate with each of the compositions through electrospray techniques.

Abstract: Embodiments relate to an apparatus for a nano-scale energy converter and an electric power generator. The apparatus includes two electrodes separated by a distance. The first electrode is manufactured to have a first work function value and the second electrode is manufactured to have a second work function value, with the first and second work function values being different. A cavity is formed by the distance between the first and second electrodes, and a nanofluid is disposed in the cavity. The nanofluid includes nanoparticles suspended in a dielectric medium. The nanoparticles have a third work function value that is greater than the first and second work function values. The relationship of the work function values of the nanoparticles to the work function values of the electrodes optimizes the transfer of electrons to the nanoparticles through Brownian motion and electron hopping.

Abstract: Embodiments relate to an apparatus for forming nano-structures with tailored properties on objects while fabricating the objects. The apparatus includes a reservoir that holds compositions therein. Each of the compositions includes a nano-structural material, a plurality of grain growth inhibitor nano-particles, and at least one of a tailoring solute and a plurality of tailoring nano-particles. A nozzle is operatively coupled to the reservoir and a translatable stage is positioned proximate to the nozzle. The stage includes a substrate holder adapted to hold a substrate. A surface profile determination device is positioned proximate to the stage to obtain profile data of the substrate. A control unit is operatively coupled to the device and the stage and regulates manufacture of a pinned nano-structure. The control unit forms deposition layers positioned proximal to the substrate with the compositions through electrospray techniques.

Abstract: Embodiments relate to an apparatus for nano-scale energy converters and electric power generators. The apparatus includes two electrodes positioned proximate to each other. An opening is positioned between the first and second electrodes. The first electrode has a first work function value and the second electrode has a different second work function value. A separation material is positioned within the opening. The separation material includes a first surface in at least partial physical contact with the first electrode and a second surface positioned opposite from the first surface. The second surface is in at least partial physical contact with the second electrode. The first and second electrodes and the separation material form an at least partially planar electric power harvesting device.

Abstract: Embodiments relate to an apparatus for energy harvesting and electric power generators, especially at the nano-scale. The apparatus includes two electrodes positioned proximate to each other. The first electrode has a first work function value and the second electrode has a different second work function value. A separation material is positioned between the first and second electrodes. The separation material includes a first surface in at least partial physical contact with the first electrode and a second surface positioned opposite from the first surface. The second surface is in at least partial physical contact with the second electrode. The first and second electrodes and the separation material form an at least partially arcuate energy harvesting device.