An impact detection device includes an impact detector, a wireless communication device, an energy storage device, an autonomous electrical energy generation device, a device for receiving energy by radio frequency, the device being configured to adopt the following two modes: a first mode, referred to as autonomous mode, in which the autonomous electrical energy generation device is configured to supply the impact detector and the wireless communication device; a second mode, referred to as external mode, in which the device for receiving energy by radio frequency is configured to supply the impact detector and the wireless communication device.

A measurement system includes a vibration generation unit that generates sound or vibration in response to a change in environmental state quantity, a vibration-driven energy harvesting unit that generates electric power using the sound or vibration generated by the vibration generation unit, and a transmission unit that is driven with the electric power generated by the vibration-driven energy harvesting unit and transmits predetermined information.

A device for harvesting motion energy, the device including an outer structure, a plurality of piezoelectric units including a permanent source of electromagnetic field (magnet or electret) attached to a piezoelectric material, where each of the piezoelectric units is fixed, at least in part, to the outer structure, an inner structure located inside the outer structure, the inner structure including a plurality of permanent sources of electromagnetic field (magnets or electrets) fixed to a rigid frame, the inner structure is configured to be suspended within the outer structure due to mutual electromagnetic forces acting between permanent sources of electromagnetic field pertaining to the piezoelectric units and permanent sources of electromagnetic field pertaining to the inner structure, and an electric circuit configured to store or provide electric energy supplied by the piezoelectric units due to strain caused by relative motion between the outer structure and the inner structure.

A device for harvesting motion energy, the device having an outer structure, multiple piezoelectric units having a permanent source of electromagnetic field (magnet or electret) attached to a piezoelectric material, where each of the piezoelectric units is fixed, at least in part, to the outer structure, where the inner structure is configured to be free to move within the outer structure, and an electric circuit configured to store or provide electric energy supplied by the piezoelectric units due to strain caused by relative motion between the outer structure and the inner structure.

Electrical connectors mountable on wheels are described. An electrical connector may include a sleeve sized for mounting on a barrel of a wheel. The sleeve defines one or more channels. The electrical connector may also include one or more hollow spokes mechanically coupled with the sleeve, and one or more electrical conductors. An electrical conductor extends from a portion of the sleeve corresponding to a bead seat region through the one or more channels and a hollow spoke for electrically coupling with an electrical module positioned on a tread region of a tire mounted on the wheel. Electrical devices including such electrical connectors and electrical devices including other electrical connectors are also described.

An energy harvester having an electromagnet and a triboelectric nanogenerator. The triboelectric nanogenerator has triboelectric layers configured to be spaced apart by a gap width. Displacement of a magnet of the electromagnet is configured to enable the triboelectric layers to contact one another, in which the gap width is configured to be smaller than the displacement.

A power generation element includes a magnetostrictive material having a fixed end in a longitudinal direction, and generates power when force is applied to the magnetostrictive material. The power generation element includes a magnetostrictive portion containing the magnetostrictive material, a magnetic portion containing a magnetic material and having surfaces at least partially fixed to the magnetostrictive portion, a coil for enclosing at least a part of the magnetostrictive material, and a first and second magnetic field generation portions to generate a magnetic field that are fixed to the magnetostrictive portion to sandwich the coil, all of which configuring a magnetic circuit. Out of the first and the second magnetic field generation portions, the magnetic field generated from the first magnetic field generation portion close to the fixed end is larger than that generated from the second magnetic field generation portion.

An electronic device includes a housing structure including a first cover facing in a first direction and forming a first surface of the electronic device, and a second cover facing in a second direction opposite to the first direction and forming a second surface of the electronic device. The electronic device also includes a display positioned in a space formed by the housing structure and exposed through the first surface. The electronic device further includes an energy harvesting structure positioned in the space and configured to generate a current from a contact input to the first surface and a sound input generated inside and outside the electronic device. The electronic device additionally includes a battery positioned in the space. The electronic device also includes a charging circuit configured to charge the battery using the current received from the energy harvesting structure.

The present disclosure relates to a piezoelectric device, and more particularly, to a piezoelectric device including: a piezoelectric actuator; a displacement transmission structure disposed on the piezoelectric actuator; and a displacement amplification structure disposed between the piezoelectric actuator and the displacement transmission structure. Here, the displacement amplification structure includes: a first displacement amplification structure and a second displacement amplification structure, which cross each other; and a fixing pin that passes through the first displacement amplification structure and the second displacement amplification structure to connect the first displacement amplification structure and the second displacement amplification structure. Also, each of one end of the first displacement amplification structure and one end of the second displacement amplification structure may be fixed on the piezoelectric actuator.

The disclosure provides a piezoelectric element and a method for manufacturing a piezoelectric element. The disclosure provides the piezoelectric element comprising: a base layer, a piezoelectric layer which is disposed on one surface of the base layer, and in which upwardly curved convex portions and downwardly curved concave portions are continuously disposed along a first direction; and contact members which are disposed on the concave portions of the piezoelectric layer and on the one surface of the base layer to connect the piezoelectric layer to the base layer.