TIME REVERSAL BEAM FOCUSING OF ULTRASONIC ARRAY TRANSDUCER ON A DEFECT IN A TWO LAYER MEDIUM

2010 ◽  
Author(s):  
Hyunjo Jeong ◽  
Jeong-Sik Lee ◽  
Chung-Hoon Lee ◽  
Donald O. Thompson ◽  
Dale E. Chimenti
Keyword(s):  
Time Reversal ◽  
Beam Focusing ◽  
Array Transducer ◽  
Ultrasonic Array ◽  
Layer Medium

scholarly journals Micromachining of High Quality PMN–31%PT Single Crystals for High-Frequency (>20 MHz) Ultrasonic Array Transducer Applications

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 512 ◽  
Author(s):  
Zhihong Lei ◽  
Yan Chen ◽  
Guisheng Xu ◽  
Jinfeng Liu ◽  
Maodan Yuan ◽  
...  
Keyword(s):  
High Frequency ◽  
Piezoelectric Coefficient ◽  
Piezoelectric Properties ◽  
Urgent Problem ◽  
High Quality ◽  
Laser Parameters ◽  
Array Transducer ◽  
Micro Cracks ◽  
Ultrasonic Array ◽  
Piezoelectric Performance

A decrease of piezoelectric properties in the fabrication of ultra-small Pb(Mg1/3Nb2/3)–x%PbTiO3 (PMN–x%PT) for high-frequency (>20 MHz) ultrasonic array transducers remains an urgent problem. Here, PMN–31%PT with micron-sized kerfs and high piezoelectric performance was micromachined using a 355 nm laser. We studied the kerf profile as a function of laser parameters, revealing that micron-sized kerfs with designated profiles and fewer micro-cracks can be obtained by optimizing the laser parameters. The domain morphology of micromachined PMN–31%PT was thoroughly analyzed to validate the superior piezoelectric performance maintained near the kerfs. A high piezoresponse of the samples after micromachining was also successfully demonstrated by determining the effective piezoelectric coefficient (d33*~1200 pm/V). Our results are promising for fabricating superior PMN–31%PT and other piezoelectric high-frequency (>20 MHz) ultrasonic array transducers.

scholarly journals Analysis of Linear Non-Destructive Testing and Evaluation Methods for Thin-Walled Structure Inspection Using Ultrasonic Array

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 146
Author(s):  
Yang Li ◽  
Zhenggan Zhou ◽  
Jun Wang
Keyword(s):  
Signal To Noise Ratio ◽  
Near Field ◽  
Central Frequency ◽  
Destructive Testing ◽  
Array Transducer ◽  
Imaging Results ◽  
Ultrasonic Array ◽  
Thin Walled ◽  
Aluminum Plates ◽  
Non Destructive

The ultrasonic array used for thin-walled structure non-destructive inspection usually has a high central frequency so that the thickness-to-acoustic wavelength ratio is greater than 10. When the ratio is much smaller than 10, the reliability of the conventional ultrasonic array method will dramatically decrease due to the influence of the acoustic near-field. This situation is unavoidable since the available central frequency of the array transducer cannot be an arbitrarily large value. To optimize the inspection performance in this case, the testing of an ultrasonic array and the evaluation of a structure whose thickness is smaller than five-times the longitudinal wavelength are analyzed in this paper. Linear ultrasonic array methods using different combinations of wave patterns, reflection times, and coupling conditions are uniformly expressed as full matrix algorithms. Simulated and experimental full matrices of 6 mm-thick aluminum plates using a 5-MHz array transducer are captured to analyze their imaging performances and sizing abilities with respect to various defects. Analyses show that the inspection results of the wedge coupling method have a much higher signal-to-noise ratio (SNR) than the results of conventional direct contact methods. Circular defects and rectangular defects can be distinguished by comparing the imaging results of different modes. For the simulated circular defect, the diameter can be measured according to the maximum image amplitude of the defect. To simulate a rectangular defect located in the lower half of the region, the nominal length can be measured using a linear function whose input is a −6 dB drop in length of the SS-S mode image. For a real sample, the material anisotropy and complex self-reflections will decrease the SNR by about 10 dB.

Curved ultrasonic array transducer for AGV applications

Ultrasonics ◽  
1989 ◽  
Vol 27 (4) ◽  
pp. 221-225 ◽  
Author(s):  
J.P. Huissoon ◽  
D.M. Moziar
Keyword(s):  
Array Transducer ◽  
Ultrasonic Array

Ultrasonic Array Transducer Using Interdigital Electrode

1984 ◽  
Vol 23 (S1) ◽  
pp. 110
Author(s):  
Ryuichi Shinomura ◽  
Hiroshi Takeuchi ◽  
Hiroshi Kanda ◽  
Kageyoshi Katakura
Keyword(s):  
Interdigital Electrode ◽  
Array Transducer ◽  
Ultrasonic Array

Transformable Ultrasonic Array Transducer for Multi-scale Imaging and Beamforming

2021 ◽  
pp. 1-1
Author(s):  
Qi Zhang ◽  
Teng Ma ◽  
Congzhi Wang ◽  
Xiangli Liu ◽  
Yongchuan Li ◽  
...  
Keyword(s):  
Multi Scale ◽  
Array Transducer ◽  
Ultrasonic Array

scholarly journals Preliminary Investigation of Magnetic Resonance Imaging Guided Beamforming in Flexible Type Ultrasonic Array Transducers

2021 ◽  
Vol 9 ◽  
Author(s):  
Koki Hasegawa ◽  
Kengo Namekawa ◽  
Shinji Takayanagi ◽  
Iwaki Akiyama
Keyword(s):  
Focal Point ◽  
Piezoelectric Materials ◽  
Preliminary Investigation ◽  
Beam Width ◽  
Lateral Direction ◽  
Practical Applications ◽  
Field Environment ◽  
Array Transducer ◽  
Ultrasonic Array ◽  
Set Up

A flexible-shaped ultrasonic array probe that can be used in a high magnetic field environment in an MRI gantry has been developed. Given that this probe can be fixed according to the shape of the skull’s surface, it is particularly applicable for imaging in the brain. To perform ultrasonic beamforming using a bent probe, it is necessary to measure the bent shape. Therefore, in this research, the curvature of the probe was estimated using MRI. A phantom with ellipse surface close to the shape of a skull was created using a 3D printer. The probe was arranged along the phantom surface to perform MRI and ultrasonic beamforming. The ultrasonic array transducer had 192 elements made from 1-3 composite piezoelectric materials with an element spacing of 0.3 mm. Eight MR position markers were attached to the probe in parallel in two rows of four each, with the array transducer in between. The delay time of each element in dynamic focusing for reception was calculated from its position estimated by the curvature of the probe. To evaluate the feasibility of this method, a B-mode image of 0.98 mm-diameter-thread targets placed in water was generated. The beam width at half maximum of the echo peak in the lateral direction from the thread target set up near the transmission focal point was calculated based on the B-mode image. It was found that the beam width of 1.32 mm in the proposed method, which was close to the thread diameter, whereas that was 4.38 mm in the conventional method that did not consider the bending of the probe. Consequently, the proposed beamforming technique is feasible for ultrasonic imaging through an arbitrary curved surface. Practical applications with a head phantom mimicking skull and cerebral tissue are expected.

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