Tohoku University

Denso Corporation

Sendai Smart Machines Co., Ltd.

Hiroki Kuwano

Takatoshi Sekizawa

Akira Takaoka

Yoichiro Suzuki

Hitoshi Kitayoshi

Haruhiko Asanuma

Hiroyuki Oguchi

Motoaki Hara

A power generation device is provided. A weight may vibrate in one direction as an axial direction in response to an external vibration. A beam may be arranged in at least one side with respect to the weight in the axial direction of the weight, and vibrate together with the weight. A piezoelectric element may be mounted on the beam. A guide may include a hollow guiding a movement of the weight in the axial direction. A stopper may be included in the weight. The stopper may restrict an amount of the movement of the weight in the axial direction within a predetermined amount. A stopper wall may stop the movement of the weight in the axial direction by contacting with the stopper.

Power generation device

A rotary system mounted piezoelectric generator has a folded beam structure in which the whole or part of a spring is formed with a piezoelectric generation element, in which one end is provided in a drive rotation system and in which a weight is attached to the other end, the degree of freedom of motion of the weight is two or more-dimensional and thus it is possible to easily change the locus thereof. The beam has a spiral structure such that when the drive rotation system is rotated, a centrifugal force applied to the weight is efficiently modulated by a second force other than the centrifugal force. A self-powered wireless communication terminal is operated with an extremely small amount of power consumption by use of a wireless connection control means and a modulation scattering response antenna which perform multilevel phase-shift keying (MPSK).

Rotary system mounted piezoelectric generator, self-powered wireless communication terminal and wireless communication system

An electrostatic induction-type vibration power generation device and method for improving a power generation amount, and extracting an external electric field from a spontaneous polarization electret. A pair of conductive plates is disposed with a gap therebetween. A charged body formed of a spontaneous polarization electret having predetermined thickness has a positively charged lower surface and negatively charged upper surface. The charged body is between conductive plates in contact with one conductive plate. The gap between the conductive plates is displaced in a direction vertical to the surfaces of the spontaneous polarization electret, whereby an electrostatic capacitance changes and electric power is generated. The other conductive plate is disposed at a position where an absolute value of an external electric field emitted outside from the charged body is between 2.7&#xd7;10V/m and 1.5&#xd7;10V/m. Moreover, the thickness of the spontaneous polarization electret is between 1 mm and 60 mm.

Electrostatic induction-type vibration power generation device and method of manufacturing the same

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Sendai, Japan

Hiroki Kuwano