scholarly journals Modeling and Experimental Characterization of Bonding Delaminations in Single-Element Ultrasonic Transducer

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2269
Author(s):  
Wenxiang Ding ◽  
Maxime Bavencoffe ◽  
Marc Lethiecq
Keyword(s):  
Ultrasonic Transducer ◽  
Ultrasonic Transducers ◽  
Single Element ◽  
Experimental Characterization ◽  
The Finite Element Method ◽  
Matching Layer ◽  
Different Types ◽  
3D Printed ◽  
Piezoelectric Disk

Ultrasonic transducers performance can be seriously deteriorated by loss of adhesion between some constitutive elements such as the active element, the backing, or the matching layer. In the present work, the influence of bonding delaminations on the performance of a single-element ultrasonic transducer, which is composed of a piezoelectric disk, a backing, and a matching layer, is studied numerically and experimentally. Based on the positions between layers, two cases, i.e., delaminations between ceramic and backing or between ceramic and matching layer, are considered. Each case involves three different types of delaminations, which are marked as delamination type (DT)-I, II, and III. DT-I, a circular shape delamination, starts from the center and expands towards the peripheric zone; DT-II, an annular shape delamination, starts from the peripheric zone and expands towards the center; DT-III is a sector shape delamination with a given angle. The numerical simulations are performed by the finite element method and the influence of delaminations on the electromechanical admittance (EMA) of the transducer is investigated. 3D printed backings and matching layers are mounted on a PZT sample to assemble delaminated single-element transducers. An impedance analyzer is used for experimental measurements. Comparison between numerical and experimental results shows a reasonable agreement making changes in EMA an interesting indicator to inform about the occurrence and severity of delaminations in a single-element ultrasonic transducer.

Design and Characterization of Capacitive Micromachined Ultrasonic Transducer

2006 ◽  
Vol 321-323 ◽  
pp. 132-135
Author(s):  
Bong Young Ahn ◽  
Ki Bok Kim ◽  
Hae Won Park ◽  
Young Joo Kim ◽  
Yong Seok Kwak
Keyword(s):  
Sacrificial Layer ◽  
Ultrasonic Transducer ◽  
Medical Engineering ◽  
Single Element ◽  
Air Atmosphere ◽  
Engineering Society ◽  
Capacitive Micromachined Ultrasonic Transducer ◽  
X 32 ◽  
2D Array

As cMUTs (capacitive Micromachined Ultrasonic Transducer) offer numerous advantages over traditional transducers in terms of efficiency, bandwidth, and cost, they are expected to replace piezoelectric transducers in many applications. In particular, 2D-array cMUTs have aroused great interest in the medical engineering society because of their ability to materialize a true volumetric ultrasonic image. In this study, single element cMUTs with 32 x 32 and 64 x 64 cells were successfully fabricated. The diameter and thickness of the membrane are 35 and 1000 nm, respectively, with a sacrificial layer thickness of 600 nm. The electric characteristics of the fabricated cMUT were measured. Tests on the efficiencies of the cMUT in terms of wave generation and in terms of detection according to the bias and pulse voltage were performed in an air atmosphere.

scholarly journals Future-Oriented Experimental Characterization of 3D Printed and Conventional Elastomers Based on Their Swelling Behavior

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4402
Author(s):  
Klara Loos ◽  
Vivianne Marie Bruère ◽  
Benedikt Demmel ◽  
Yvonne Ilmberger ◽  
Alexander Lion ◽  
...  
Keyword(s):  
Tensile Tests ◽  
Swelling Behavior ◽  
Uniaxial Tensile ◽  
Stress And Strain ◽  
Experimental Characterization ◽  
Synthetic Fuels ◽  
Fuel Component ◽  
3D Printed ◽  
Fuel Components

The present study investigates different elastomers with regard to their behavior towards liquids such as moisture, fuels, or fuel components. First, four additively manufactured materials are examined in detail with respect to their swelling in the fuel component toluene as well as in water. The chemical nature of the materials is elucidated by means of infrared spectroscopy. The experimentally derived absorption curves of the materials in the liquids are described mathematically using Fick’s diffusion law. The mechanical behavior is determined by uniaxial tensile tests, which are evaluated on the basis of stress and strain at break. The results of the study allow for deriving valuable recommendations regarding the printing process and postprocessing. Second, this article investigates the swelling behavior of new as well as thermo-oxidatively aged elastomers in synthetic fuels. For this purpose, an analysis routine is presented using sorption experiments combined with gas chromatography and mass spectrometry and is thus capable of analyzing the swelling behavior multifacetted. The transition of elastomer constituents into the surrounding fuel at different aging and sorption times is determined precisely. The change in mechanical properties is quantified using density measurements, micro Shore A hardness measurements, and the parameters stress and strain at break from uniaxial tensile tests.

Experimental Droplet Formation of Magnetostrictive Inkjet Head to the Change of Driving Waveform

2011 ◽  
Vol 314-316 ◽  
pp. 2334-2337
Author(s):  
Jae Hyun Yoo ◽  
Young Woo Park ◽  
Kyung Hyun Yoon ◽  
Eun Ju Yoo
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Fluid Flows ◽  
Droplet Formation ◽  
Experimental Characterization ◽  
Droplet Volume ◽  
Waveform Control ◽  
Different Types ◽  
Driving Waveform

This paper presents the experimental characterization of droplet formation in accordance with different types of driving waveform. The objective of the experiments is to generate sound droplets with a minimal volume depending on the types of driving waveform. For it, two types of driving waveform are used to investigate the droplet formation of the M-Jet: one is bipolar and another W-shaped. In the case of the bipolar waveform, ti lead to fluid flows from the liquid reservoir into the chamber in the M-Jet and th is time to impose a pulse under the constant magnetic field, resulting in the formation of the droplets. The droplet volume decreases as ti increases, and increases with further increase of ti. The threshold ti is equal to 500 s. The droplet volume decreases as th decreases, but the droplet formation was not successful at less than 550 s. In the case of the W-shaped waveform, maintains ti and th where is set from bipolar waveform, control the tr, where retracted MM keeps to control droplet volume. The tail becomes longer as tr increases. The droplet volume remains nearly constant as tr increases, but rapidly increases with further increase of tr. When the two driving waveform, the W-shaped driving waveform seems to be effective in reducing the droplet volume, and achieves the reduction of volume by 30 percent.

Development of Fluxgate Magnetometers Based on Fe61Co19Si5B15 Amorphous Ribbons

2014 ◽  
Vol 605 ◽  
pp. 697-700
Author(s):  
Sotiria Vaitsi
Keyword(s):  
Magnetic Field ◽  
Magnetic Core ◽  
Field Variable ◽  
Experimental Characterization ◽  
Dc Voltage ◽  
Amorphous Ribbons ◽  
Different Types ◽  
The Magnetic Field

This paper deals with the characterization of fluxgate magnetometers that adopt a Fe61Co19Si5B15 ribbons as magnetic core. The experimental characterization concerned the dependence of Δt and ΔV according to the magnetic field Hdc. The change of the field (variable input) held by changing the offset, adding a small dc voltage to ac, taking in extremely important results. Still, examined the dependence of ΔV on the frequency for two different types of coils, a circular and an oval coil, made of the same material, Fe61Co19Si5B15.

scholarly journals Experimental Characterization of an Embossed Capacitive Micromachined Ultrasonic Transducer Cell

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 217
Author(s):  
Yuanyu Yu ◽  
Jiujiang Wang ◽  
Xin Liu ◽  
Sio Hang Pun ◽  
Shuang Zhang ◽  
...  
Keyword(s):  
Ultrasonic Transducer ◽  
Experimental Characterization ◽  
Release Process ◽  
Output Pressure ◽  
Collapse Mode ◽  
Acoustic Instruments ◽  
Capacitive Micromachined Ultrasonic Transducer ◽  
Collapse Region ◽  
High Output

Capacitive Micromachined Ultrasonic Transducer (CMUT) is a promising ultrasonic transducer in medical diagnosis and therapeutic applications that demand a high output pressure. The concept of a CMUT with an annular embossed pattern on a membrane working in collapse mode is proposed to further improve the output pressure. To evaluate the performance of an embossed CMUT cell, both the embossed and uniform membrane CMUT cells were fabricated in the same die with a customized six-mask sacrificial release process. An annular nickel pattern with the dimension of 3 μ m × 2 μ m (width × height) was formed on a full top electrode CMUT to realize an embossed CMUT cell. Experimental characterization was carried out with optical, electrical, and acoustic instruments on the embossed and uniform CMUT cells. The embossed CMUT cell achieved 27.1% improvement of output pressure in comparison to the uniform CMUT cell biased at 170 V voltage. The fractional bandwidths of the embossed and uniform CMUT cells were 52.5% and 41.8%, respectively. It substantiated that the embossed pattern should be placed at the vibrating center of the membrane for achieving a higher output pressure. The experimental characterization indicated that the embossed CMUT cell has better operational performance than the uniform CMUT cell in collapse region.

Experimental characterization of the mechanical properties of 3D-printed ABS and polycarbonate parts

2017 ◽  
Vol 23 (4) ◽  
pp. 811-824 ◽  
Author(s):  
Jason T. Cantrell ◽  
Sean Rohde ◽  
David Damiani ◽  
Rishi Gurnani ◽  
Luke DiSandro ◽  
...  
Keyword(s):  
Yield Strength ◽  
Shear Modulus ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Experimental Characterization ◽  
Shear Testing ◽  
Content Type ◽  
Offset Yield Strength ◽  
3D Printed

Purpose This paper aims to present the methodology and results of the experimental characterization of three-dimensional (3D) printed acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) parts utilizing digital image correlation (DIC). Design/methodology/approach Tensile and shear characterizations of ABS and PC 3D-printed parts were performed to determine the extent of anisotropy present in 3D-printed materials. Specimens were printed with varying raster ([+45/−45], [+30/−60], [+15/−75] and [0/90]) and build orientations (flat, on-edge and up-right) to determine the directional properties of the materials. Tensile and Iosipescu shear specimens were printed and loaded in a universal testing machine utilizing two-dimensional (2D) DIC to measure strain. The Poisson’s ratio, Young’s modulus, offset yield strength, tensile strength at yield, elongation at break, tensile stress at break and strain energy density were gathered for each tensile orientation combination. Shear modulus, offset yield strength and shear strength at yield values were collected for each shear combination. Findings Results indicated that raster and build orientations had negligible effects on the Young’s modulus or Poisson’s ratio in ABS tensile specimens. Shear modulus and shear offset yield strength varied by up to 33 per cent in ABS specimens, signifying that tensile properties are not indicative of shear properties. Raster orientation in the flat build samples reveals anisotropic behavior in PC specimens as the moduli and strengths varied by up to 20 per cent. Similar variations were observed in shear for PC. Changing the build orientation of PC specimens appeared to reveal a similar magnitude of variation in material properties. Originality/value This article tests tensile and shear specimens utilizing DIC, which has not been employed previously with 3D-printed specimens. The extensive shear testing conducted in this paper has not been previously attempted, and the results indicate the need for shear testing to understand the 3D-printed material behavior fully.

scholarly journals Experimental Characterization of A Piezoelectric Transducer Array Taking into Account Crosstalk Phenomenon

2020 ◽  
Vol 10 (1) ◽  
pp. 01-14
Author(s):  
Abdelmajid Bybi ◽  
Driss Khouili ◽  
Christian Granger ◽  
Mohammed Garoum ◽  
Ahmed Mzerd ◽  
...  
Keyword(s):  
Piezoelectric Transducer ◽  
Ultrasonic Transducer ◽  
Critical Role ◽  
Experimental Characterization ◽  
Transducer Array ◽  
The Third ◽  
Transducer Arrays ◽  
Piezoelectric Elements ◽  
Thickness Mode

Ultrasonic transducer arrays are generally composed of several piezoelectric elements arranged in 1D or 2D ways. Crosstalk is an undesirable phenomenon decreasing the performance of these devices. It generates parasitic displacements at the elements' radiating surfaces, which changes the directivity of the array. Furthermore, the transducer's displacement plays a critical role in terms of the focal area and transferred intensities. The objective of this paper is to characterize a piezoelectric array composed of seven-elements made of PZ 27 ceramic experimentally. It investigates the effects of the crosstalk phenomenon on the array's performance in particular. The results have shown that the array's elements vibrate mainly in thickness mode, but the displacement is not uniform along their length due to the contribution of a parasitic length mode. Moreover, the major parasitic displacements are obtained on the neighboring passive elements: about -7.3 dB, -11 dB, and -12 dB, on the first, the second, and the third elements, respectively.

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