National Taiwan University

Other

National Science Council

Far Eastone Telecommunications Co., Ltd.

Tung Thih Electronic Co., Ltd.

Advancewave Technology, Inc.

Wen-Hsin Hsiao

Chih-Kung Lee

Wen-Jong Wu

Wen-Ching Ko

Jia-Lun Chen

Yu-Chi Chen

Yu-Hsiang Hsu

Shih-Yuan Lee

Chih-Chiang Cheng

Jen-Hsuan Ho

Ing Yih Leu

Hsu-Ching Liao

Han-Lung Chen

Chun-Kuang Chen

Chia-Yu Lin

Chih-Wen Hsieh

Herman Chunghwa Rao

Chih-Ting Lin

Ching-Hsiang Hsu

Hsueh-Ching Shih

Chuin-Shan Chen

Yen-Chieh Wang

Yu-Yuan Chen

Yih-Fan Chen

Yi-Chun Chen

Jung Nan Hung

Jay Shieh

Ing-Yih Leu

Ji-De Huang

Yao-Tien Huang

Shieh Jay

Lee Chih-Kung

Yuan-Ping Liu

An electret loudspeaker device including a diaphragm, a first perforated electrode and a first spacer is provided. The diaphragm includes a first electret, a second electret, a polymer layer and an electrode layer. At least one layer of the first electret or the second electret is formed by expanded polytetrafluoroethylene. The second electret is stacked on one side of the first electret, while the electrode layer is stacked on the opposite side of the first electret. The polymer layer is made of a hydrophobic material and is disposed on the second electret. The first perforated electrode is stacked on a first spacer and close to the polymer layer. The first spacer disposed between the diaphragm and the first perforated electrode supports the first perforated electrode over the diaphragm and defines a first chamber. A fabrication method of the electret loudspeaker device is also provided.

Electret loudspeaker device

A method of making a nonfluoropolymer electret film is provided. The method may include: providing a polymer-containing solution, the polymer-containing solution comprising at least one polymer material, at least one solvent, and at least one surfactant, spreading the polymer-containing solution to provide a wetting polymer film, removing at least a portion of the solvent in the wetting polymer film to provide a polymer film, and conducting a Corona charging to the polymer film to form the electret film.

Method of manufacturing an electret film

An electret loudspeaker device including a diaphragm, a first perforated electrode and a first spacer is provided. The diaphragm has an electret layer and an electrode layer. The first perforated electrode is stacked on a side of the diaphragm near the electret layer, and has multiple holes. The first spacer is stacked between the diaphragm and the first perforated electrode, and includes a first distribution area and plural second distribution areas. The first distribution area has first openings penetrating through the first spacer, and each first opening has a first opening space volume between the diaphragm and the first perforated electrode. Each second distribution area has second openings penetrating through the first spacer, and each second opening has a second opening space volume between the diaphragm and the first perforated electrode. A difference between the first and the second opening space volumes is greater than 10%.

A sound-generating device comprises at least two first enclosures and a thin film. The at least two first enclosures with at least one first bendable element coupled between two neighboring first enclosures. The thin film comprising at least one electrode and at least one piezoelectric layer, the at least one electrode being coupled with a terminal of an audio signal output, wherein the at least one piezoelectric layer is configured to respond to a signal supplied by the audio signal output and to generate sound waves. The thin film and the at least two first enclosures are coupled together forming at least two first cavities between the thin film and the first enclosure, and the first bendable element is attached to the thin film.

Flexible piezoelectric sound-generating devices

A sound-generating device comprises a first enclosure having at least one first electrode and a first piezoelectric layer, a first terminal of an audio signal output being coupled to the at least one first electrode of the first enclosure, a second enclosure having at least one first electrode and a first piezoelectric layer, and a first bendable element coupled between the first and second enclosures. The at least one first electrode is coupled with the first terminal of the audio signal output. The first piezoelectric layer of the first enclosure and the first piezoelectric layer of the second enclosure are configured to respond to the signal supplied by the audio signal output and to generate sound waves.

A speaker comprises at least one electrode electrically coupled with an audio signal input and a film comprising at least one electret layer. The film is configured to interact with the electrode in response to an audio signal supplied by the audio signal input and to vibrate to generate sound waves. The electret layer is formed from a polymer-containing solution.

Electret materials, electret speakers, and methods of manufacturing the same

A flexible actuator comprises a thin film and at least one first enclosure with at least one first bendable element coupled to the first enclosure. The thin film may comprise a conductive layer and a first electret layer over a first surface of the conductive layer. The thin film is configured to be bendable. The first enclosure have a first electrode layer as part of the first enclosure. The first enclosure is provided over the first electret layer with the first electrode layer being spaced apart from the first electret layer. The first electrode layer is coupled with a first terminal of an audio signal input. The thin film is configured to interact with the first enclosure in response to audio signals supplied by the audio signal input and to generate sound waves.

Flexible electret actuators and methods of manufacturing the same

A speaker system that includes an audio signal-receiving interface, a modulating circuit, a phase-control circuit, and a number of speaker units. The audio signal-receiving interface is configured to receive an audio signal, and the modulating circuit is coupled with the audio signal-receiving interface. The modulating circuit is configured to modulate a low frequency component of the audio signal and to generate a modulated signal. The phase-control circuit is coupled with the modulating circuit and the audio signal-receiving interface. The phase-control circuit is configured to receive the modulated signal and a high-frequency component of the audio signal and to control a phase of the modulated signal, a phase of the high-frequency component of the audio signal, or both. The speaker units are coupled with the phase-control circuit and configured to generate sound waves based on signals supplied by the phase-control circuit.

Electrostatic loudspeaker array

An ultrasound transducer has a cup-shaped casing. The cup-shaped casing has a sidewall. A cross section of an inner surface of the sidewall being perpendicular to a central axis of the ultrasound transducer substantially shows a dumbbell-shaped contour. The dumbbell-shaped contour has a pair of opposite straight-line sections being substantially parallel to a longitudinal axis of the dumbbell-shaped contour and a pair of opposite arc sections being located respectively at two ends of the longitudinal axis of the dumbbell-shaped contour and respectively forming two enlarged portions of the dumbbell-shaped contour. Two ends of each arc section of the dumbbell-shaped contour respectively joint the straight-line sections through two curve sections and each curve section is connected to one end of the arc section and one straight-line section. At least one enlarged area of a dumbbell-shaped surface of an inside bottom surface has a recessed portion.

Ultrasound transducer with a dumbbell-shaped chamber

In the present invention, a dual-output piezoelectric transformer for driving at least two loads is provided. The dual-output piezoelectric transformer comprises a piezoelectric piece, a set of input electrodes mounted centrally on a first and a second sides of the piece with a first polarization direction along a thickness direction of the piece, and a first and a second output electrodes polarized reversely in a second polarization direction and respectively mounted around surfaces of two ends of the piece with the second polarization direction being a longitudinal direction of the piece.

Multi-output piezoelectric inverter and transformer thereof

The invention advantageously provides an alert system and method for geographic or natural disasters that utilize a telecommunications network for monitoring geographic data in disaster-prone areas and accordingly issuing warnings against potential disasters to people inside the monitored area. An alert system according to a preferred embodiment of the invention comprises a telecommunications service network, one or more wireless sensor modules and a control center. The telecommunications network according to this particular embodiment includes service coverage over the monitored areas. The wireless sensor modules are installed to selected locations inside monitored areas. Each of the sensor modules further comprises at least one sensor for collecting geographic or geodetic data and a wireless communications unit for sending collected geographic data to the control center via the telecommunications network. The control center then receives and processes the monitored geographic or geodetic data sent by the wireless sensor modules for further algorithmic analysis. The control center accordingly issues alerts for imminent geographic or natural disasters if the processing of the geographic or geodetic data produces adverse results.

Alert system and method for geographic or natural disasters utilizing a telecommunications network

Augmenting surface electrodes for piezoelectric workpieces together with the method for fabrication are disclosed for improving fabrication and operation reliability of the workpieces. A piezoelectric workpiece used for energy conversion between electrical and mechanical forms in a piezoelectric system comprises a body, a number of function electrodes, and at least an augmenting surface electrode. The body of piezoelectricity is used for implementing the energy conversion. The function electrodes are each fixedly attached to the surface of the body, and are connected in the electric circuit for implementing the energy conversion. At least one of the function electrodes has a shape with a contour of at least one acute angle. At least an augmenting surface electrode has a substantially elongated shape fixedly attached to the surface of the body proximate to the acute angle. Together, the augmenting surface electrode and the proximate function electrode thereof constitute a gross electrode that substantially cancels the acute angle when both are connected electrically to the same electric potential. The acute angle is cancelled during the polarization of electric dipoles of the body grain molecules so that the boundary region between different polarization orientation distribution regions can be smoothed. The reliability of the piezoelectric workpiece is improved both during the fabrication and during normal operation of the workpiece.

Augmenting surface electrode for piezoelectric workpiece

An innovative piezoelectric transducer apparatus having a piezoelectric workpiece with a modal-shaped actuator electrode for converting an input energy of one form into an output energy of another form. The piezoelectric workpiece comprises an actuator section and a sensor section. The actuator section is formed in the piezoelectric workpiece and has a modal-shaped electrode for exciting the piezoelectric workpiece into mechanical vibration upon driven by the input energy. The sensor section is also formed in the piezoelectric workpiece and has a sensor electrode for delivering the output energy to an external load of the apparatus by picking up the energy generated by the excitation. The modal-shaped actuator electrode has a shape function defined by the mathematical solution function of the governing equation of the piezoelectric workpiece under the condition that the piezoelectric workpiece being vibrating in a selected resonant mode.

Piezoelectric transducer apparatus having a modal-shaped electrode

The present invention discloses a vibration measuring device for measuring a vibration of an object. Such device includes a sensing body generating a dynamic information in response to the vibration, and a piezoelectric sensing layer disposed on the sensing body to construct a sensor and formed in a distributed mode to measure the dynamic information in a selected specific bandwidth. The present invention also discloses a vibration measuring method.

Growing community of inventors

Longtan, Taiwan

Wen-Hsin Hsiao