An electromagnetic energy harvester for converting vibrations of a body to electricity that includes a coil with two ends that is wound along a longitudinal axis of a ferromagnetic core, a magnet, and a suspending device that its first end is designed to be fixed to the body and its second end is designed to be fixed to the magnet. The first end of the core is design to be at close proximity to the magnet and the longitudinal axis of the core is designed to be substantially aligned vertically to the magnetic axis of the magnet. The vibrations of the body can cause a relative alternating movement between the core and the magnet that can create alternating voltage between the ends of the coil.

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.

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.

A vibrational energy harvester element includes: a first electrode; a second electrode that moves in a predetermined direction with respect to the first electrode; a third electrode; a fourth electrode that moves in the predetermined direction with respect to the third electrode; and a support portion that supports the second electrode and the fourth electrode so that they are movable along the predetermined direction; and wherein: the first electrode and the third electrode are disposed along the predetermined direction; at least one of facing surfaces of the first electrode and the second electrode, and at least one of facing surfaces of the third electrode and the fourth electrode, are electrically charged; and the support portion supports the second electrode and the fourth electrode in a state in which electrostatic force between the first electrode and the second electrode, and electrostatic force between the third electrode and the fourth electrode are balanced along the predetermined direction.

A normal-temperature heat engine power generation device based on a drinking bird is provided. The device includes a drinking bird body, a piezoelectric module and an electromagnetic module. The piezoelectric module includes a cantilever beam, a piezoelectric sheet arranged on the cantilever beam and working loads arranged at an end of the cantilever beam. when a head of the drinking bird body swings downwards, a tip of a beak can impact the working loads. The electromagnetic module includes magnets, coils and coil magnet conducting columns. The magnets are arranged at a bottom of a spherical bottom of the drinking bird body, and the coil magnet conducting columns sleeving the coils are arranged on a base of the drinking bird body.

An electromagnetic energy harvester for converting vibrations of a body to electricity that includes a coil with two ends that is wound along a longitudinal axis of a ferromagnetic core, a magnet, and a suspending device that its first end is designed to be fixed to the body and its second end is designed to be fixed to the magnet. The first end of the core is design to be at close proximity to the magnet and the longitudinal axis of the core is designed to be substantially aligned vertically to the magnetic axis of the magnet. The vibrations of the body can cause a relative alternating movement between the core and the magnet that can create alternating voltage between the ends of the coil.

The module comprises a pendular unit with an elastically deformable piezoelectric beam having a clamped end and an opposite, free end, coupled to an inertial mass. The beam produces an oscillating electrical signal collected by electrodes, which is rectified and regulated to output a voltage for charging a battery. The number and configuration of the electrodes (T1, T2, B1, B2, N) carried by the piezoelectric beam define a plurality of pairs of electrodes between which a corresponding plurality of said oscillating signals can be simultaneously collected. A switching matrix, as a function of an input command, selectively switches the plurality of pairs of electrodes between each other according to a plurality of different series (S), parallel (P) and/or series-parallel (SP) configurations, the selected configuration being that which maximizes the power sent to the battery as a function of the voltage level (VBAT) present at the terminals of the latter.

A vibrational energy harvester element includes: a first electrode; a second electrode that moves in a predetermined direction with respect to the first electrode; a third electrode; a fourth electrode that moves in the predetermined direction with respect to the third electrode; and a support portion that supports the second electrode and the fourth electrode so that they are movable along the predetermined direction; and wherein: the first electrode and the third electrode are disposed along the predetermined direction; at least one of facing surfaces of the first electrode and the second electrode, and at least one of facing surfaces of the third electrode and the fourth electrode, are electrically charged; and the support portion supports the second electrode and the fourth electrode in a state in which electrostatic force between the first electrode and the second electrode, and electrostatic force between the third electrode and the fourth electrode are balanced along the predetermined direction.

An energy harvesting system is disclosed that is especially well-suited for use on aerodynamic systems such as guided projectiles or other aerobodies. A series of piezoelectric cantilevers are arranged to capture vibrations from the ambient environment and transduce the mechanical motion from the vibrations into useful electrical energy. The piezoelectric cantilevers can be arranged along different planes from one another to capture different vibrational modes and directions. A power conditioning circuit is included to receive the electrical energy produced by the piezoelectric cantilevers. A storage element coupled to the power conditioning circuit is configured to store charge based on the electrical energy produced by the plurality of piezoelectric cantilever structures. The stored charge can be used to provide low levels of power to certain electrical components on board the aerodynamic system before it has been launched.

Described herein is a novel piezoelectric energy harvester based on a metamaterial structure capable of scavenging energy from multiple low-frequency ambient vibrations employing a mass-in-mass Phononic crystal structure and comprised of a piezoelectric snail structure, encapsulated in a cylindrical rubber matrix, and encased in a rigid cubic frame.