A method for measuring mechanical parameters of a multilayer composite thin film structure and belongs to the technical field of online tests of micro-electro-mechanical system (MEMS for short) material parameters. Equivalent Young modulus and equivalent residual stress of each layer of the multilayer composite thin film structure can be obtained in one step by means of solving an equation set on the basis of a relationship between first-order resonance frequency of multilayer composite fixed-fixed beams and multilayer composite cantilever beams and parameters such as material characteristics and structure size, the online test of multilayer thin film materials can be realized, the test structure and calculating method are simple, and the accuracy is higher. The present invention further discloses a device for measuring mechanical parameters of the multilayer composite thin film structure.

A piezoelectric element has a first electrode layer, a piezoelectric layer on the first electrode layer, a second electrode layer on the piezoelectric layer, a third electrode layer on part of the second electrode layer and including third metal, and an insulating layer covering at least a part of the piezoelectric layer not provided with the second electrode layer and having an aperture exposing a part of the second electrode layer. The second electrode layer has a first layer including first metal and a second layer including second metal on the first layer. The second layer is exposed in the aperture. A difference in standard redox potential between the second metal and the third metal is smaller than a difference in standard redox potential between the first metal and the third metal.

A signal sensing module includes a substrate, a sensing electrode, a piezoresistive material layer and a sensing circuit. The substrate has a surface. The sensing electrode is disposed on the substrate and is exposed from the surface. The piezoresistive material layer is formed on the surface and covers the sensing electrode. The piezoresistive material layer has a resistance value. The sensing circuit is disposed in the substrate and adapted to sense a change of resistance value when a pressure wave passes through the piezoresistive material layer.

In described examples of a CMOS IC, an ultrasonic transducer having terminals is formed on a substrate of the IC. CMOS circuitry having ultrasonic signal terminals is formed on the substrate. At least one metal interconnect layer overlies the ultrasonic transducer and the CMOS circuitry. The at least one metal interconnect layer connects the CMOS circuitry ultrasonic signal terminals to the terminals of the ultrasonic transducer.

A thermoacoustic probe with an electromagnetic (EM) energy applicator, a thermoacoustic transducer, and a housing containing the applicator and thermoacoustic transducer and enabling an EM exit window and a transducer front face to be held flush with respect to each other. A first acoustic absorbing material is placed between the EM applicator and the transducer, between the EM applicator and the housing, and between the transducer and the housing as spacers; and a second acoustic absorbing material is injected between the EM applicator and the transducer, between the EM applicator and the housing, and between the transducer and the housing in the spaced gaps, wherein the first acoustic absorbing material and the second acoustic absorbing material are combined to form a sleeve covering the applicator sides and the transducer sides. The acoustic absorbing materials mitigate sound artifacts and noise resulting in cleaner signal data. In a preferred embodiment the applicator is a radio-frequency applicator, the transducer is a piezoelectric transducer, and the probe is utilizable for tissue imaging.

Ultrasonic devices include a transducer having a piezoelectric element therein that may operate as an acoustic signal receiving surface and/or an acoustic signal generating surface. At least one acoustic matching layer is provided on the piezoelectric element. This at least one acoustic matching layer may be configured as a composite of N acoustic matching layers, with a first of the N acoustic matching layers contacting the primary surface of the piezoelectric element. This first acoustic matching layer may have an acoustic impedance equivalent to Z.sub.L1, where N is a positive integer greater than zero. In some embodiments of the invention, the magnitude of Z.sub.L1 may be defined as: 0.75 ((Z.sub.p).sup.N+1(Z.sub.g)).sup.1/(N+2)Z.sub.L11.25 ((Z.sub.p).sup.N+1(Z.sub.g)).sup.1/(N+2), where Z.sub.p is the acoustic impedance of the piezoelectric element (e.g., lead zirconate titanate (PZT)) and Z.sub.g is the acoustic impedance of a compatible gas.

A piezoelectric element has a diaphragm, a first electrode on the diaphragm, a piezoelectric layer on the first electrode, and a second electrode on the piezoelectric layer. The piezoelectric layer is a stack of multiple piezoelectric films and is made of a perovskite composite oxide containing lead, zirconium, and titanium and represented by the general formula ABO.sub.3, with the molar ratio of the A-site to the B-site (A/B) in the perovskite composite oxide being 1.14 or more and 1.22 or less. In current-time curve measurement, the activation energy calculated from relaxation current using an Arrhenius plot is 0.6 [eV] or less. The relaxation current is the amount of current at the time at which a downward trend in current turns upward.

An apparatus includes an XY scanning mechanism, a first transducer configured to transmit a sound wave, a second transducer configured to receive the sound wave, and a tray configured to hold a material. The tray is coupled to the XY scanning mechanism and located beneath the first transducer and the second transducer is located on a bottom side of the tray below the material. The tray is moved in an XY pattern along an X axis and a Y axis in response to an XY scanning mechanism controller mechanically moving the XY scanning mechanism while the first transducer is positioned in a stationary location along a vertical axis perpendicular to the tray. The first transducer transmits sound waves into the material and the second transmitter receives the transmitted sound waves at each XY position.

An ultrasound transducer array probe arranged as a layered structure having at least one layer of transducer array elements, and at least one further layer mounted in at least one of i) acoustic, and ii) thermal contact with said layer of transducer elements. The further layer has particles of a polymer core coated with at least one surface layer of a material that at least one of i) determines an acoustic impedance, and ii) a thermal conductivity of the further layer. The density of particles provides for a large number of particles to be in contact with neighboring particles, and the further layer is, at least across a part of its surface, coated with an electrically isolating layer that is so thin that the effect of the isolating layer on acoustic and thermal performance of the further layer is negligible.

Provided is a sensor and method for weld defect detection. The sensor includes several piezoelectric elements which form a matrix arranged on a flexible substrate. Each piezoelectric element is covered with a damping block and surrounded by sound absorbing material, and packaged within a flexible protective film. The sensor is simple, highly adaptable and high detection efficiency, which is especially suitable for the quick in-service inspection of long distance welds in large equipment, it has high degree of automation.