A MEMS ultrasonic transducer imager array with beam width, acoustic power, and frequency modulations

2012 ◽  
Author(s):  
Tahereh Arezoo Emadi ◽  
Gabriel Thomas ◽  
Douglas A. Buchanan ◽  
Stephen Pistorius
Keyword(s):  
Ultrasonic Transducer ◽  
Beam Width ◽  
Acoustic Power ◽  
Frequency Modulations

Beam-Width-Controllable Ultrasonic Transducer Array

2003 ◽  
Vol 42 (Part 1, No. 5B) ◽  
pp. 3198-3199 ◽  
Author(s):  
Jung-Ho Kim ◽  
In-Jin Song ◽  
Chun-Duck Kim ◽  
Moo-Joon Kim ◽  
Kang-Lyeol Ha ◽  
...  
Keyword(s):  
Ultrasonic Transducer ◽  
Beam Width ◽  
Transducer Array

Calibrating Ultrasonic Images for the NDE of Structural Materials

1994 ◽  
Vol 116 (3) ◽  
pp. 640-646 ◽  
Author(s):  
R. S. Gilmore ◽  
A. M. Glaeser ◽  
J. C. Wade
Keyword(s):  
Imaging System ◽  
Ultrasonic Transducer ◽  
Ultrasonic Imaging ◽  
Beam Width ◽  
Practical Method ◽  
Image Resolution ◽  
Detection Sensitivity ◽  
Manufacturing Companies ◽  
Turbine Engine ◽  
The Individual

Ultrasonic imaging is taking a larger and larger role in the NDE of turbine engine materials and in support of fracture mechanics calculations. It is also playing an increasing role in quality and process control. For most fracture toughness calculations, it is necessary to establish the accuracy with which a flaw’s size and shape are imaged, whether single or multiple flaws are involved, and the spacing of multiple flaws. Because of these requirements, resolution, as well as detection sensitivity, has become an issue. There are a number of resolution targets that can provide this type of calibration information for an ultrasonic imaging system. A fused quartz USAF 1951 target, similar to the patterns used in this work, was first used by Gilmore (1986), but Gilmore’s pattern was superficial and subsurface evaluations were limited to focusing on the pattern from the opposite side of the blank and monitoring the reflection from what is now the target backwall. Work by Paton (1977) did produce buried targets in titanium samples, but there was no practical method to produce buried targets in high-temperature ceramics until the techniques developed by Rodel and Glaeser (1987) were used to produce the targets described in this paper. Optically transparent resolution targets make it feasible to verify visually that the resolution target has been correctly fabricated. An image of the target with a candidate ultrasonic transducer then permits quantitative image resolution estimates to be made even when the interrogating acoustic beam contains significant refractive aberration. This is important because useful subsurface images can be acquired with the use of acoustic beams that are aberrant to the point that diffraction-limited beam-width calculations are meaningless. This work also demonstrates how the interdisciplinary skills of manufacturing companies can be combined with those of universities to produce results that any one of the individual members of the team could not have produced alone, without significant increases in labor, time, and cost.

scholarly journals Low-frequency ultrasound can drive the transport of nanoparticles and molecules in polymer gels for biotechnology applications

2019 ◽  
Vol 3 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Donald K. Martin
Keyword(s):  
Direct Contact ◽  
Ultrasonic Transducer ◽  
Low Frequency ◽  
Polymer Gels ◽  
Acoustic Power ◽  
Outer Retina ◽  
Low Frequency Ultrasound ◽  
Frequency Ultrasound

Abstract This paper reports the use of low-frequency ultrasound to influence transport in porous hydrogels with a transducer attached in direct contact with the hydrogel. This is a different configuration than for ultrasound-generating devices utilized previously for enhancing transport of molecules. The advantages of the system reported in this manuscript are that (i) much less acoustic power is required to influence the transport in the hydrogel that is in direct contact with the ultrasonic transducer, and (ii) no cavitation is induced in the hydrogel to influence the transport. This system was first tested in bench-top in vitro experiments by quantifying the transport of gold nanoparticles stimulated by low-frequency ultrasound. Then, to provide an in vivo example for potential biotechology applications, the system was demonstrated to be capable of transporting drugs across the tunics of a rabbit eye into the ocular circulation so as to target the transported drug to the outer retina.

scholarly journals Acoustic Power Measurement and Thermal Bioeffect Evaluation of Therapeutic Langevin Transducers

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 624
Author(s):  
Jinhyuk Kim ◽  
Jungwoo Lee
Keyword(s):  
Temperature Rise ◽  
Thermal Ablation ◽  
Ultrasonic Transducer ◽  
Average Power ◽  
Acoustic Power ◽  
Acoustic Energy ◽  
Power Measurement ◽  
Maximum Temperature ◽  
Experimental Investigations ◽  
Driving Voltage

We recently proposed an analytical design method of Langevin transducers for therapeutic ultrasound treatment by conducting parametric study to estimate the effect of compression force on resonance characteristics. In this study, experimental investigations were further performed under various electrical conditions to observe the acoustic power of the fully equipped transducer and to assess its heat-related bioeffect. Thermal index (TI) tests were carried out to examine temperature rise and thermal damage induced by the acoustic energy in fatty porcine tissue. Acoustic power emission, TI values, temperature characteristics, and depth/size of thermal ablation were measured as a function of transducer’s driving voltage. By exciting the transducer with 300 Vpp sinusoidal continuous waveform, for instance, the average power was 23.1 W and its corresponding TI was 4.1, less than the 6 specified by the Food and Drug Administration (FDA) guideline. The maximum temperature and the depth of the affected site were 74.5 °C and 19 mm, respectively. It is shown that thermal ablation is likely to be more affected by steep heat surge for a short duration rather than by slow temperature rise over time. Hence, the results demonstrate the capability of our ultrasonic transducer intended for therapeutic procedures by safely interrogating soft tissue and yet delivering enough energy to thermally stimulate the tissue in depth.

scholarly journals Orthogonal Chirp Coded Excitation in a Capacitive Micro-machined Ultrasonic Transducer Array for Ultrasound Imaging: A Feasibility Study

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 883
Author(s):  
Bae-Hyung Kim ◽  
Seungheun Lee ◽  
Kang-Sik Kim
Keyword(s):  
Feasibility Study ◽  
Ultrasonic Transducer ◽  
Low Frequency ◽  
Beam Width ◽  
Ultrasonic Transducers ◽  
Experimental Result ◽  
Frequency Bandwidth ◽  
Coded Excitation ◽  
Short Pulses ◽  
Bandwidth Characteristic

It has been reported that the frequency bandwidth of capacitive micro-machined ultrasonic transducers (CMUTs) is relatively broader than that of other ceramic-based conventional ultrasonic transducers. In this paper, a feasibility study for orthogonal chirp coded excitation to efficiently make use of the wide bandwidth characteristic of CMUT array is presented. The experimental result shows that the two orthogonal chirps mixed and simultaneously fired in CMUT array can be perfectly separated in decoding process of the received echo signal without sacrificing the frequency bandwidth each chirp. The experimental study also shows that frequency band-divided orthogonal chirps are successfully compressed to two short pulses having the −6 dB axial beam-width of 0.26- and 0.31-micro second for high frequency and low frequency chirp, respectively. B-mode image simulations are performed using Field II to estimate the improvement of image quality assuming that the orthogonal chirps designed for the experiments are used for simultaneous transmission multiple-zone focusing (STMF) technique. The simulation results show that the STMF technique used in CMUT array can improve the lateral resolution up to 77.1% and the contrast resolution up to 74.7%, respectively. It is shown that the penetration depth also increases by more than 3 cm.

Nanoparticles Generation using Mono-disperse Droplets by an Ultrasonic Transducer

2020 ◽  
Vol 140 (2) ◽  
pp. 37-42
Author(s):  
Nozomu Fujimoto ◽  
Takefumi Kanda ◽  
Masaya Katsuta ◽  
Yusaku Sakata ◽  
Yoshiaki Yamada ◽  
...  
Keyword(s):  
Ultrasonic Transducer

Optimizing Gas-Assisted Processes for Ga and Xe FIB Circuit Edit Application

2016 ◽  
Author(s):  
Valery Ray ◽  
Josef V. Oboňa ◽  
Sharang Sharang ◽  
Lolita Rotkina ◽  
Eddie Chang ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Structural Damage ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Width ◽  
Ion Source ◽  
Reconstruction Technique ◽  
Beam Diameter ◽  
Current Profile ◽  
Single Beam

Abstract Despite commercial availability of a number of gas-enhanced chemical etches for faster removal of the material, there is still lack of understanding about how to take into account ion implantation and the structural damage by the primary ion beam during focused ion beam gas-assisted etching (FIB GAE). This paper describes the attempt to apply simplified beam reconstruction technique to characterize FIB GAE within single beam width and to evaluate the parameters critical for editing features with the dimensions close to the effective ion beam diameter. The approach is based on reverse-simulation methodology of ion beam current profile reconstruction. Enhancement of silicon dioxide etching with xenon difluoride precursor in xenon FIB with inductively coupled plasma ion source appears to be high and relatively uniform over the cross-section of the xenon beam, making xenon FIB potentially suitable platform for selective removal of materials in circuit edit application.

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