Piezoelectric transducers have been widely used for the generation and detection of ultrasonic waves for structural health monitoring. Recently, we proposed the use of inductive coupling in order to implement wireless coupling to a Lamb wave transducer. In that transducer the ultrasonic waves were generated by a piezoelectric wafer attached to the surface of a plate. These transducers are effec...

Ultrasonic sensors are commonly used for a wide variety of non-contact presence, proximity or distance measuring applications in industry, especially the automotive branch. This paper shows how the radiation properties of bending-type ultrasonic transducers with rotational symmetry depend on shape, dimensions and material parameters. In order to determine their dependencies, the behaviour of su...

Broadband transmission of ultrasound in water using capacitive, micromachined transducers is reported. Transmission experiments using the same pair of devices at 4, 6, and 8 MHz with a signal-to-noise ratio greater than 48 dB are presented. Transmission is observed from 1 to 20 MHz. Better receiving electronics are necessary to demonstrate operation beyond this range. Furthermore, the same pair...

Sandwiched piezoelectric transducers are widely used, especially in high power applications. For more convenient analysis and design, a PSpice lossy model of sandwiched piezoelectric ultrasonic transducers in longitudinal vibration is proposed by means of the one-dimensional wave and transmission line theories. With the proposed model, the resonance and antiresonance frequencies are obtained, a...

Piezoceramics have been the dominant transducer technology in ultrasound medical imaging for several decades. Recent progress in surface micromachined capacitive ultrasonic immersion transducers makes them an alternative transducer technology, especially in highly integrated twodimensional arrays. This paper demonstrates that the surface micromachined capacitive ultrasonic immersion transducer ...

In order to improve resolution of ultrasonic imaging, high frequency scanners which are employed in the range 20 MHZ to 50 MHz are needed. As a result, it is critical to obtain data on ultrasonic scattering and attenuation in this frequency range. At these high frequencies, it is not feasible to make scattering measurements with unfocused transducers; therefore focused transducers are needed. U...

Vibration power and amplitude are essential factors in ultrasonic drawing processes, especially for difficult-to-draw materials like titanium and its alloys. This paper presents a new composite power-superimposed ultrasonic vibrator for wire drawing which was driven by three separate ultrasonic transducers. The transducers were uniformly distributed around the circular cross section of the vibr...

Non-contact ultrasonic, enables rapid testing of structures using ultrasonic tests that are not possible via conventional contact transducers. This paper reports on laser ultrasonic and air/gas coupled ultrasonic measurements that are performed remotely, do not require direct access to test area, do not need traditional ultrasonic coupling and do not have traditional C-scan fixture requirements...

Piezoelectric micromachined ultrasonic transducers (pMUTs) are an example of the application of MEMS technology to ultrasound generation and detection, which is expected to offer many advantages over conventional transducers. In this work, we investigate pMUTs through novel design and fabrication methods. A finite element (FE) model, with original tools to measure device performance, was develo...

ABSTRACT Conventional methods of ultrasonic non-destructive evaluation (NDF.) use liquids to couple sound waves into the test sample. This either requires immersion of the parts to he examined or the use of complex and bulky water squirting systems that must be scanned over the structure. Air-coupled ultrasonic systems eliminate these requirements if the losses at air-solid interfaces are toler...