An apparatus includes an outer structure body having an inner surface defining a cavity and an inner structure body rotatably supported within the cavity. The inner structure body has an outer surface in opposing relation to the inner surface and a central bore. Movable elements are positioned along the inner surface and movably coupled to the outer structure body. Ball elements are positioned along the outer surface and coupled to the inner structure body for movement with the inner structure body. The ball elements releasably contact the movable elements and impart motion to the movable elements in response to relative motion between the inner structure body and the outer structure body. Energy harvesters are positioned to generate electrical charges based on piezoelectric effect or magnetostrictive effect when motion is imparted to the movable elements by the ball elements.

A method includes converting an electrical output provided by an energy generator with a first voltage converter; and, subsequent to converting the electrical output provided by the energy generator with the first voltage converter, activating, with a microprocessor, a second voltage converter for converting the electrical output provided by the energy generator with the second voltage converter. An electrical device with a microprocessor for selecting one of two or more voltage converters is also described.

A thermal battery including: a casing; a battery cell disposed in the casing; a heat generating pyrotechnic material, separate from the battery cell, at least partially surrounding the battery cell; and insulation disposed between the heat generating pyrotechnic material and the casing, wherein the heat generating pyrotechnic material is disposed in a flattened tube having a flat cross-section where at least two sides are substantially parallel, the flattened tube being spirally wound to form a shape corresponding to a complimentary shape of at least a portion of the battery cell.

An intelligent energy harvesting device, a voltage signal application system, and an energy management module thereof are disclosed. The intelligent energy harvesting device is used to transfer a signal to an application device. The intelligent energy harvesting device includes a power generation module, a battery and an energy management module. The power generation module generates a first voltage signal. The battery generates a second voltage signal. The energy management module is electrically connected to the power generation module and the battery for enabling the first voltage signal output from the power generation module to be used as a power signal to provide the application device, or enabling the first voltage signal output from the power generation module and the second voltage signal output from the battery collectively serves as the power signal to provide the application device.

A controller-transmitter transmits acoustic energy through the body to an implanted acoustic receiver-stimulator. The receiver-stimulator converts the acoustic energy into electrical energy and delivers the electrical energy to tissue using an electrode assembly. The receiver-stimulator limits the output voltage delivered to the tissue to a predetermined maximum output voltage. In the presence of interfering acoustic energy sources output voltages are thereby limited prior to being delivered to the tissue.

Aspects of self-powered weigh-in-motion systems and methods that utilize piezoelectric components for sensing load as well as powering data acquisition and analysis components. In one example, the weigh-in-motion system includes a number of piezoelectric stacks, each stack including a number of piezoelectric elements. Each stack includes one or more top or upper piezoelectric element that provides vehicle sensing data. Each stack also includes a set of piezoelectric elements used for energy harvesting. The sensing piezoelectric elements are connected to a data input of a microcontroller for vehicle classification, while the energy harvesting piezoelectric elements are connected to a power input of the microcontroller.

A measurement system includes: a vibration-driven energy harvesting unit that generates electric power from sound, vibration, or displacement; a power supply controller that controls an amount of power consumption of a power supply based on the electric power generated by the vibration-driven energy harvesting unit; a detector that is driven by electric power supplied by the power supply controller and detects an environment state quantity; and a transmitter that is driven by electric power supplied by the power supply controller and transmits information regarding the environment state quantity detected by the detector.

A device is disclosed, which includes: a charge portion with a plurality of piezoelectric elements embedded in a tire configured for a vehicle, a capacitor mechanically coupled to the tire and electrically coupled to the plurality of piezoelectric elements; a transmitter coil, mechanically coupled to the tire and electrically coupled to the capacitor through a discharge portion; wherein in response to an external radial pressure on the tire resulting from movement of the vehicle which causes a pressure on the plurality of piezoelectric elements, the plurality of piezoelectric elements produce an electrical charge on the capacitor, and wherein the discharge portion electrically connects the electrical charge on the capacitor to the transmitter coil to send electromagnetic power to the vehicle.

A smart ring is configured harvest mechanical energy using piezoelectricity. The smart ring includes a ring-shaped housing, a power source disposed within the ring-shaped housing, and a charging circuit. The charging circuit includes a piezoelectric harvesting element, and is configured to charge the power source when user motion causes a mechanical deformation in the piezoelectric harvesting element. The smart ring further includes a component, disposed within the ring-shaped housing and configured to draw energy from the power source, and further configured to perform at least one of: i) sense a physical phenomenon external to the ring-shaped housing, ii) send communication signals to a communication device external to the ring-shaped housing, or iii) implement a user interface.

The present invention is directed to a power bank with the capability to harvest electric energy which is then configured to charge its onboard battery such that the power bank is self-recharging. The energy harvesting power bank has an internal area provided with a piezoelectric mass suspended within a suspension frame by resilient members. The internal area is lined with piezoelectric film that is impacted by the piezoelectric mass as a result of the kinetic energy derived from movement of the power bank. As a consequence, the piezoelectric materials will generate electrical energy which will undergo conditioning by energy harvester electronics. The conditioned electrical energy is used to provide power to the USB charging port for use in recharging portable devices.