Energy harvesting devices and methods for converting the mechanical energy of a flowing ionic solution, such as rainwater or seawater, into electric energy are provided. The energy harvesting devices include an electric current generating device that includes a metal layer and an amphoteric metal oxide film disposed over a surface of the metal layer. By moving an electric double layer across the surface of the amphoteric metal oxide film, an electric current is generated in the metal layer.

A thermoelectric conversion device includes: an insulating layer; and a thermoelectric conversion module disposed on the insulating layer. The thermoelectric conversion module has a first thermoelectric conversion region and a second thermoelectric conversion region. The first(second) thermoelectric conversion region includes one or two or more thermoelectric conversion elements, a first(third) connection electrode, and a second(fourth) connection electrode. The thermoelectric conversion elements of the first(second) thermoelectric conversion region are electrically connected to the first(third) connection electrode and the second(fourth) connection electrode and located on an electric path connecting these connection electrodes. Each of the thermoelectric conversion elements includes a thermoelectric converter. The thermoelectric converter of at least one of the thermoelectric conversion elements has a phononic crystal layer having a phononic crystal structure including a plurality of regularly arranged through holes. A through direction of the plurality of through holes in this crystal structure is substantially parallel to a direction perpendicular to a principal surface of the insulating layer.

A thermoelectric conversion device includes: a first thermoelectric conversion module, a first insulating layer, and a second thermoelectric conversion module. The first (second) thermoelectric conversion module includes one or two or more thermoelectric conversion elements, a first (third) connection electrode, and a second (fourth) connection electrode. The thermoelectric conversion elements of the first (second) thermoelectric conversion module are electrically connected to the first (third) connection electrode and the second (fourth) connection electrode and located on an electric path connecting these connection electrodes. Each of the thermoelectric conversion elements includes a thermoelectric converter. The thermoelectric converter of at least one of the thermoelectric conversion elements has a phononic crystal layer having a phononic crystal structure including a plurality of regularly arranged through holes. A through direction of the plurality of through holes in this crystal structure is substantially parallel to a stacking direction of the first thermoelectric conversion module, the first insulating layer, and the second thermoelectric conversion module.

Described herein are devices incorporating Casimir cavities, which modify the quantum vacuum mode distribution within the cavities. The Casimir cavities can create energy differences within layers or device to drive energy from or to a portion of a layer disposed adjacent to or contiguous with the Casimir cavity by modifying the quantum vacuum mode distribution incident on one portion of the layer to be different from the quantum vacuum mode distribution incident on another portion of the layer. Additionally, Casimir cavities in which the cavity layer comprises a conductor that can be used to carry a flow of electrical power induced by the presence of the Casimir cavity.

Modular inflation systems and inflation segments including an inflation enclosure and a plurality of artificial muscle layers provided within the inflation enclosure in a stacked arrangement, each of the plurality of artificial muscle layers including one or more artificial muscles, wherein one or more plurality of artificial muscles of each of the plurality of artificial muscle layers are operable between an actuated state and a non-actuated state, and one or more fastening members for attaching the inflation segment to another inflation segment.

A layered actuation structure includes a first platform pair and a second platform pair. Each of the first platform pair and the second platform pair include an actuation platform and a mounting platform, forming an actuation cavity of each of the first platform pair and the second platform pair. One or more connecting ledges of each platform pair couple at least one of the actuation platform and the mounting platform of each platform pair to at least one of an actuation arm and a support arm, respectively. A collective stiffness of the one or more connecting ledges of the first platform pair is different than a collective stiffness of the one or more connecting ledges of the second platform pair. The layered actuation structure also includes one or more artificial muscles disposed in the actuation cavity of the first platform pair and the second platform pair.

Apparatus, method(s), and system(s) according to which electric power is generated in one or more coils by rotating a magnetic field generated by one or more permanent magnets. The one or more coils are connected to a collar. The collar is positioned downhole in an oil and gas wellbore. The one or more permanent magnets are connected to a rotor positioned within an internal passageway of the collar. A fluid is communicated along the internal passageway of the collar. The rotor, and thus the magnetic field generated by the one or more permanent magnets, are rotated using the fluid communicated along the internal passage.

The technical description relates to energy storage systems and methods. Specific examples described herein relate to in-ground energy storage systems and methods of selectively discharging electrical energy from an energy storage system. An example energy storage system comprises a first fluid storage tank, a second fluid storage tank, a first fluid disposed in the first fluid storage tank, a second fluid disposed in the second fluid storage tank, a heating unit operably connected to the first fluid storage tank and adapted to heat the first fluid, a cooling unit operably connected to the second fluid storage tank and adapted to cool the second fluid, and an energy conversion unit exposed to the first fluid and the second fluid. The energy conversion unit is adapted to convert a temperature difference between the first fluid and the second fluid directly to electrical energy or indirectly to electrical energy through intermediate mechanical work, such as rotational motion.

A thermionic (TI) power cell includes a heat source, such as a layer of radioactive material that generates heat due to radioactive decay, a layer of electron emitting material disposed on the layer of radioactive material, and a layer of electron collecting material. The layer of electron emitting material is physically separated from the layer of electron collecting material to define a chamber between the layer of electron collecting material and the layer of electron emitting material. The chamber is substantially evacuated to permit electrons to traverse the chamber from the layer of electron emitting material to the layer of electron collecting material. Heat generated over time by the layer of radioactive material causes a substantially constant flow of electrons to be emitted by the layer of electron emitting material to induce an electric current to flow through the layer of electron collecting material when connected to an electrical load.

A thermoelectric generator includes: a heat-receiving plate (2) having a heat-receiving surface (2A) configured to receive radiant heat; a thermoelectric generation module provided to a surface of the heat-receiving plate (2) opposite from the heat-receiving surface (2A) and having an area smaller than an area of the heat-receiving plate (2); a cooling plate provided to a surface of the thermoelectric generation module opposite from a surface where the heat-receiving plate (2) is provided; and a temperature equalizer (22) provided to the heat-receiving plate (2) and configured to equalize a temperature of the heat-receiving surface (2A).