Denso Corporation

Nippondenso Co., Ltd.

National Institute of Advanced Industrial Science and Technology

Tokyo University of Science Foundation

Institute of Science Tokyo

Kazuhiko Kano

Yukihiro Takeuchi

Kenichi Ao

Akihiko Teshigahara

Yoshinori Ohtsuka

Junji Oohara

Toshimasa Yamamoto

Hiroshi Muto

Kazuki Arakawa

Minekazu Sakai

Tetsuo Yoshioka

Takamoto Watanabe

Tsuyoshi Fukada

Morito Akiyama

Hirofumi Uenoyama

Kazushi Asami

Takao Iwaki

Masakazu Kanosue

Junji Ohara

Yasutoshi Suzuki

Makiko Sugiura

Toshiyuki Morishita

Minoru Murata

Nobuyuki Kato

Noriyuki Matsushita

Nobuyuki Ohya

Yumi Tanaka

Yoshitaka Noda

Hideaki Yamada

Yoshihiro Kozawa

Kenichi Nara

Tadashi Hattori

Inao Toyoda

Seiichiro Ishio

Hirofumi Higuchi

Toshiki Isogai

Shinji Yoshihara

Seiji Fujino

Naohiro Ueno

Yoshitaka Gotoh

Nobuaki Kawahara

Hiroshige Sugito

Keiko Nishikubo

Norio Kitao

Koji Hattori

Kenichi Sakai

Yoshinori Otsuka

Takatoki Yamamoto

Toshihiro Kamohara

Shingo Jinno

Kazuhisa Nakagawa

Yukihiko Takeuchi

Makiko Fujita

Hiroki Otsuka

Tetsuo Y Shioka

Yusuke Edano

Kozo Shibata

Akira Nukazuka

Kei Hayakawa

A power generator includes a power generating unit and at least one of a power storage unit or an output unit that is electrically connected to the power generating unit. The power generating unit includes an electret having a first charged surface and a second charged surface that are charged with opposite polarities, a first electrode formed on the first charged surface, and a second electrode formed on the second charged surface. The electret is formed by polarizing an electret material that includes an inorganic dielectric having a bandgap energy of 4 eV or more. At least one of the first electrode or the second electrode are partially disposed on the corresponding charged surface such that at least one of the first charged surface or the second charged surface has a portion as a current collecting surface exposed outward.

Power generator having an electret for harvesting energy

A power generator includes an electret including a first charged surface and a second charged surface having opposite polarities, a first electrode partially formed on the first charged surface, a second electrode formed on the second charged surface, a third electrode disposed to face the first charged surface with a space, and at least one of a power storage unit or an output unit. The first charged surface has a current collecting surface that is exposed outward. The first electrode and the second electrode form a first power generating unit and the third electrode and the second electrode form a second power generating unit. The electret is formed by polarizing an electret material that includes an inorganic dielectric having a bandgap energy of 4 eV or more.

Power generator

Provided is a piezoelectric film including an AlN crystal, and a first element and a second element doped to the AlN crystal. The first element is an element having an ionic radius larger than an ionic radius of Al. The second element is an element having an ionic radius smaller than the ionic radius of Al. Also provided are piezoelectric film laminated body including an underlayer and a piezoelectric film including ScAlN, and a method of manufacturing the same. The underlayer has a crystal lattice having six-fold symmetry or three-fold symmetry. Also provided are a piezoelectric film including ScAlN having a laminated structure of a hexagonal crystal and a cubic crystal, and a method of manufacturing the same. The cubic crystal is doped with an element other than trivalent element.

Piezoelectric film, method of manufacturing same, piezoelectric film laminated body, and method of manufacturing same

A piezoelectric thin film is formed through sputtering and consists essentially of scandium aluminum nitride. The carbon atomic content is 2.5 at % or less. When producing the piezoelectric thin film, scandium and aluminum are sputtered simultaneously on a substrate from a scandium aluminum alloy target material having a carbon atomic content of 5 at % or less in an atmosphere where at least nitrogen gas exists. The sputtering may be conducted also by applying an ion beam on an opposing surface of the alloy target material at an oblique angle. Moreover, aluminum and scandium may be also sputtered simultaneously on the substrate from an Sc target material and an Al target material. As a result, a piezoelectric thin film which exhibits excellent piezoelectric properties and a method for the same can be provided.

Piezoelectric thin film and method for producing the same

A method for manufacturing a piezoelectric thin film including an aluminum nitride thin film containing scandium on a substrate, the method includes: sputtering step for sputtering aluminum and scandium under an atmosphere containing at least a nitrogen gas. In the sputtering step in the method according to the present invention, a scandium content rate falls within the range from 0.5% by atom to 50% by atom when a temperature of the substrate falls within the range from 5&#xb0; C. to 450&#xb0; C. during the sputtering step.

Manufacturing method of piezoelectric-body film, and piezoelectric-body film manufactured by the manufacturing method

In a SAW device, a first area placed at a surface of a measurement subject directly under a propagation portion is fixed to the measurement subject, and a second area placed at the surface of the measurement subject directly under both a drive electrode and a reflector is not fixed to the measurement subject. When a strain is generated in the measurement subject, a strain is generated only in the propagation portion, and a phase change is generated in a surface acoustic wave reflected by the reflector. Because the phase change is hardly affected by a temperature change, the strain of the measurement subject can be measured based on the phase change. Because a resonant frequency of the SAW device is changed by the temperature change, but is not affected by the strain of the measurement subject, a temperature can be measured based on a resonant frequency change.

Surface acoustic wave sensor

In a SAW oscillator, each of a first SAW element and a second SAW element includes interdigital electrodes and a reflector formed on a piezoelectric material. A first oscillating circuit part forms an oscillating loop including the first SAW element. A second oscillating circuit part forms an oscillating loop including the second SAW element. The first and second oscillating circuit parts have an identical admittance property. The first and second SAW elements are configured that an electrode pitch is identical and an admittance property indicating a relation between a frequency and an admittance value is different therebetween. Further, a first intersection point between the admittance property of the first SAW element and the admittance property of the first oscillating circuit part and a second intersection point between the admittance property of the second SAW element and the admittance property of the second oscillating circuit part are at different frequencies.

Surface acoustic wave oscillator

A surface acoustic wave device is disclosed. The surface acoustic wave device includes: a substrate having a plane surface; multiple first electrodes formed on the plane surface of the substrate; and multiple second electrodes formed on the plane surface of the substrate. Each of the first and second electrodes has a predetermined closed ring shape. The first and second electrodes are concentric. The second electrodes are located radially inside or radially outside of the first electrodes.

Surface acoustic wave device having concentrically arranged electrodes

An angular rate sensor comprises a piezoelectric film having a first and a second surfaces forming an x-y plane and utilizes a perturbation mass coherently vibrating elastic acoustic waves on which a Coriolis force acts when the angular rate sensor undergoes a rotary motion about an x-direction. A first elastic acoustic wave is excited in the piezoelectric film by a driving transducer and a second elastic acoustic wave generated by the Coriolis force proportional to an angular rate of the rotary motion of the angular rate sensor itself is detected by the detecting transducer. The angular rate sensor further comprises at least a first electrode disposed on the first surface of the piezoelectric film for discharging a surface charge caused due to piezoelectric effect at the lower surface of the film in which the first elastic acoustic wave is excited.

Angular rate sensor

A surface acoustic wave element includes a piezoelectric member, a comb-teeth electrode, and a reflector. The comb-teeth electrode is arranged on the piezoelectric member. The reflector is arranged on the piezoelectric member. The reflector reflects a surface acoustic wave transmitted from the comb-teeth electrode. The reflector has a plurality of areas, and each of the areas has a frequency to make a reflection efficiency the largest. At least two of the frequencies of the areas are made different from each other.

Surface acoustic wave element, method of producing the same, and method of changing resonation frequency of the same

A yaw rate sensor has two sets of exciting electrodes, perturbative weights and two sets of detecting electrodes on a surface of a piezoelectric substrate. The exciting electrodes excite first surface acoustic waves transmitted through the surface of the substrate in a propagation direction. The weights are oscillated by the waves and excite a second surface acoustic wave, transmitted through the surface of the substrate in a detection direction orthogonal to the propagation direction, in response to a yaw applied to the weights. The detecting electrodes measure an intensity of the second surface acoustic wave to detect the yaw rate. The sets of exciting electrodes are symmetrically placed with respect to a driving axis extending straight along the propagation direction. The group of weights is symmetric with respect to the driving axis.

Yaw rate sensor using surface acoustic wave

A piezoelectric thin film of the present invention includes an aluminum nitride thin film that contains scandium. A content ratio of scandium in the aluminum nitride thin film is 0.5 atom % to 50 atom % on the assumption that a total amount of the number of scandium atoms and the number of aluminum atoms is 100 atom %. According to this arrangement, the piezoelectric thin film of the present invention can improve a piezoelectric response while keeping characteristics of elastic wave propagation speed, Q value, and frequency-temperature coefficient that the aluminum nitride thin film has.

Piezoelectric thin film, piezoelectric material, and fabrication method of piezoelectric thin film and piezoelectric material, and piezoelectric resonator, actuator element, and physical sensor using piezoelectric thin film

An optical device includes a semiconductor substrate and an optical part having a plurality of columnar members disposed on the substrate. Each columnar member is disposed in a standing manner and adhered each other so that the optical part is provided. The optical part is integrated with the substrate. This optical part has high design freedom.

Optical device having micro lens array

A capacitance type physical quantity sensor detects physical quantity. The sensor includes a movable portion including a movable electrode and a fixed portion including a fixed electrode. The fixed electrode includes a detection surface facing a detection surface of the movable electrode. The movable electrode is movable toward the fixed electrode in accordance with the physical quantity so that a distance between the detection surfaces is changeable. At least one of the movable and the fixed electrodes includes a groove. The groove is disposed on a top or a bottom of the one of the movable and the fixed electrodes, has a predetermined depth from the top or the bottom, and extends from the detection surface to an opposite surface.

Capacitance type physical quantity sensor

Growing community of inventors

Toyoake, Japan

Kazuhiko Kano