Quartz crystal microbalance (QCM) is a highly sensitive mass sensor and has been widely used in many fields. However, the nonuniform distribution of mass sensitivity will lead to poor reproducibility of QCM, which is not conducive to the application of QCM in some fields. Considering the effect of electrode shape, size, and material on mass sensitivity distribution, we found that for an AT-cut QCM

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Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers.

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Acoustic resonators based on antiferromagnetic crystals of “easy plane” type, like $\alpha $ -Fe 2 O 3 or FeBO 3 , are of interest for applications in magnetoacoustic sensors of electrical and mechanical values because of high sensitivity of their resonance frequency to variations of external magnetic field or mechanical stress. One of the requirements for magnetic control of resonators is a single-value

High-intensity focused ultrasound (HIFU) has been used for noninvasive treatment of breast tumors, but the present magnetic resonance imaging (MRI)-guided HIFU (MRI-HIFU) systems encounter skin burn. In this study, a novel MRI-HIFU breast ablation system was developed to improve the above problem. The system consisted of the ring HIFU phased-array transducer, a commercial power amplifier, the mechanical

This article provides a fundamental study into the trade-offs between the location of piezoceramic elements, resonant frequency, and achievable ultrasonic vibration amplitude at the working end of the bolted Langevin-style transducers (BLTs) for ultrasonically assisted machining (UAM) applications. Analytical models and finite-element (FE) models are established for theoretical study, which are then

The shear mode film bulk acoustic wave resonators (FBARs) have been developed rapidly in recent years due to the increased interest in biosensors. In this article, the mode coupling effects that are unavoidable in real devices are theoretically analyzed and discussed. Mindlin’s approximation method of expanding the displacement fields with power series along the plate thickness direction is employed

This work investigates the role of microstructure on the radiation tolerance of relaxor-ferroelectric, lead magnesium niobate-lead titanate, thin films for piezoelectric microelectromechanical system (MEMS) applications. Thin films comprised of 0.7Pb[Mg 1/3 Nb 2/3 ]O 3 -0.3PbTiO 3 were fabricated via chemical solution deposition on platinized silicon wafers. Processing parameters, i.e., pyrolysis and

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In the context of nondestructive testing (NDT), this article proposes an inverse problem approach for the reconstruction of high-resolution ultrasonic images from full matrix capture (FMC) data sets. We build a linear model that links the FMC data, i.e., the signals collected from all transmitter–receiver pairs of an ultrasonic array, to the discretized reflectivity map of the inspected object. In

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Magnetomotive ultrasound imaging is the identification of tissue in which magnetic nanoparticle tracers are present by detecting a magnetically induced motion. Although the nanoparticles have a magnetization that depends nonlinearly on the external magnetic field, this has often been neglected and the presence of resulting higher harmonics in the detected motion has not been reported yet. Here, the

Pulse wave velocity (PWV) is the most important index for quantifying the elasticity of an artery. The accurate estimation of the local PWV is of great relevance to the early diagnosis and effective prevention of arterial stiffness. In ultrasonic transit time-based local PWV estimation, the locations of time fiduciary point (TFPs) in the upstrokes of the propagating pulse waves are inconsistent because

Abdominal imaging suffers from a particularly difficult acoustic environment - targets are located deep and overlying tissue layers with varying properties generate acoustic clutter. Increasing array size can overcome the penetration and lateral resolution problems in ideal conditions, but how the impact of clutter scales with increasing array extent is unknown and may limit the benefits in vivo. Previous

The use of mechanically-representative phantoms is important for experimental validation in ultrasound imaging, elastography and image registration. This paper proposes a model to predict the elastic modulus of a soft tissue-mimicking phantom based on two very easily controllable parameters: gelatin concentration and refrigeration duration. The model has been validated on small and large-scale phantoms:

Various modulation approaches, such as amplitude and frequency modulations, have been applied widely to modify the acoustic field and improve the performance of ultrasound imaging and therapy. However, phase modulation (PM) has not been investigated extensively in the ultrasound applications, especially at a long-pulse duration. In this study, the effects of PM on the acoustic field were investigated

Patients with unresectable or nonablatable tumors are difficult to cure, but nanotherapy combining targeted nanoparticles has many severe side effects due to the toxicities of anticancer drugs. We found that acoustic energy can produce a local region with high concentration from a low concentration suspended liquid of nano-SiO 2 particles at 2.5 MHz. Our calculated results show that the main reason

In the last 30 years, the contrast-to-noise ratio (CNR) has been used to estimate the contrast and lesion detectability in ultrasound images. Recent studies have shown that the CNR cannot be used with modern beamformers, as dynamic range alterations can produce arbitrarily high CNR values with no real effect on the probability of lesion detection. We generalize the definition of CNR based on the overlap

Intravascular acoustic radiation force impulse (IV-ARFI) imaging has the potential to identify vulnerable atherosclerotic plaques and improve clinical treatment decisions and outcomes for patients with coronary heart disease. Our long-term goal is to develop a thin, flexible catheter probe that does not require mechanical rotation to achieve high-resolution, real-time IV-ARFI imaging. In this work

In this study, a phase-cancelled backing layer for ultrasound linear array transducer is presented. The proposed backing layer is composed of multiple blocks operated by phase inversion technique. Inside of the proposed backing layer, the phase of the reflected signal can be cancelled by adjusting acoustic impedance, piezoelectric layer contact area, and thickness of each block constituting the backing

The present work is an extension of a model previously developed by our group to simulate the electroacoustic response of CMUT-based (Capacitive Micromachined Ultrasonic Transducers) linear arrays acoustically loaded by a fluid medium. The goal is to introduce the viscoelasticity effects of the propagation medium into the modeling. These effects are mainly due to the passivation layer used to protect

This article presents a resonant cavity-based array design for piezoelectric micromachined ultrasonic transducers (PMUTs). The cavity depth is designed to ensure that its open end achieves a considerably smaller acoustic impedance than the surrounding PMUT cells. The interference acoustic wave generated between every two adjacent PMUT cells at the near surface of the array will take an easy path down

A linear piezoelectric micromachined ultrasound transducer (PMUT) array was fabricated and integrated into a device for photoacoustic imaging (PAI) of tissue phantoms. The PMUT contained 65 array elements, with each element having 60 diaphragms of [Formula: see text] diameter and [Formula: see text] pitch. A lead zirconate titanate (PZT) thin film was used as the piezoelectric layer. The in-air vibration

Intravascular ultrasound (IVUS) is one of the most useful tools available today to assist intravascular stenting procedures. Having higher resolution is very important for helping doctors to evaluate the nature of atherosclerotic plaques. The current commercial IVUS systems have a spatial resolution of 70– $200~\mu \text{m}$ in the axial direction and 200– $400~\mu \text{m}$ in the lateral direction

Additive manufacture has been heralded as a disruptive technology with the potential to revolutionise manufacturing and transform how products are consumed. Within the power ultrasonic and sonar transducer domain, the capability of additive manufacture technologies to generate highly complex geometries could facilitate a step change in device performance, yet the employment of metallic additive manufactured

Magnetic hysteresis properties are sensitive to stress in ferromagnetic materials. This suggests that magnetic measurements are a potential method to evaluate residual stress in steel products. Nevertheless, nondestructive inspection of residual stress by using magnetic properties has been limited, because bulk properties over the entire sample are usually obtained in conventional hysteresis curve

Nondestructive testing for identifying defects on the surface of metal materials is important for industries and infrastructures. The Rayleigh wave is widely used for detecting these surface defects. For replacing piezoelectric transducers with electromagnetic acoustic transducers (EMATs) for the surface inspection of metal materials, this article proposes a new magnet and coil combination consisting

This article presents the design and testing of a novel two-directional (2-D) piezoelectric stack-based energy harvester for capturing the mechanical energy from the human footstep. The uniqueness of the harvester lies in the fact that the energy of 2-D excitation is scavenged by a single piezoelectric stack transducer, which can reduce the loss of harvestable energy. The harvester is constructed by

We experimentally demonstrate the dynamical tuning of the acoustic field in a surface acoustic wave (SAW) cavity defined by a periodic arrangement of metal stripes on LiNbO3 substrate. Applying a DC voltage to the ends of the metal grid results in a temperature rise due to resistive heating that changes the frequency response of the device up to 0.3%, which can be used to control the acoustic transmission

Lamb waves propagating in piezoelectric plate covered by thin film electrodes with arbitrary conductivity are investigated. The structure consists of three parts, piezoelectric plate, top and bottom thin films with arbitrary conductivities and top and bottom free space. The governing equations in each parts are first solved respectively, and then continuous conditions are used to form the propagating

A novel piezoelectric XY platform driven by a single actuator was presented for large travel range and compact structure. The actuator operated at the inertial mechanism and moved the output platform step-by-step. A dynamic model of the piezoelectric actuator was established based on the Timoshenko beam theory and Galerkin procedure, which was used to aid the structure design. The dynamic model of

We report a high-performance pulsed optically pumped (POP) Rb clock based on a novel magnetron-type microwave cavity. The cavity has a volume of 30 mL, enabling a highly homogenous microwave field distribution. With the laser frequency tuning to the ground-state hyperfine level F=2 of D2 line, we observe a Ramsey fringe contrast of 52% in terms of optical absorption detection. The resultant shot noise

Here, we report the characteristics of zero-bias capacitive micromachined ultrasonic transducers (CMUT) in various aspects, considering the transmission and reception sensitivity and evaluation of the long-term stability with AC transmission in immersion. The main idea of the zero-bias CMUT implementation is that the charge is injected by the dielectric charging effects in an insulation layer in the

A novel quartz crystal resonator (QCR) sensor with a printed-on-crystal conductive coil, named sensor coil, is presented. The sensor coil electromagnetically coupled to an external readout coil allow to perform contactless interrogation of the QCR working as a stand-alone sensor unit. A frequency-domain readout technique is adopted that allows dual-harmonic operation by detecting the QCR frequencies

This article presents a comprehensive guide to codesign lithium niobate (LiNbO 3 ) lateral overtone bulk acoustic resonators (LOBARs) and voltage-controlled oscillators (VCOs) using discrete components on a printed circuit board (PCB). The analysis focuses on understanding the oscillator-level tradeoffs between the number of locked tones, frequency stability, tuning range, power consumption, and phase

This article aims to develop a semi-noncontact stress-sensing system using a laser-generated ultrasound (LGU) wave assisted by candle soot nanoparticle (CSNP) composite. While the acoustoelastic effect is commonly targeted to measure the stress level, efforts to combine it with the LGU wave signal have been lacking due to weak signal intensity. In this study, the CSNP-based transducer is designed to

We demonstrate time and frequency transfer using a White Rabbit (WR) time transfer system over millimeter-wave (mm-wave) 71–76 GHz carriers. To validate the performance of our system, we present overlapping Allan deviation (ADEV), time deviation (TDEV), and phase statistics. Over mm-wave carriers, we report an ADEV of ${7.1}\times {10}^{-{12}}$ at 1 s and a TDEV of <10 ps at 10 000 s. Our results show

Novel pulsed-Doppler methods for perfusion imaging are validated using dialysis cartridges as perfusion phantoms. Techniques that were demonstrated qualitatively at 24 MHz, in vivo , are here examined quantitatively at 5 and 12.5 MHz using phantoms with the blood-mimicking fluid flow within cellulose microfibers. One goal is to explore a variety of flow states to optimize measurement sensitivity and

Mode-switchable ferroelectric thin-film bulk acoustic resonators (FBARs) are presented. Such resonators operate based on a dynamic nonuniform effective piezoelectricity in composite multilayer ferroelectrics with large electrostriction coefficients, like barium strontium titanate (BST). Harmonic resonance modes ( $\textit {nf}_{o}$ ) of a multilayer ferroelectric bulk acoustic wave (BAW) resonator

The National Time Service Center (NTSC), Chinese Academy of Sciences (CAS), Xi’an, China, has developed a method for common-view time transfer using Geostationary Earth Orbit (GEO) satellite (GCV) applicable to the time and frequency transfer at distant stations. This method is independent of Global Navigation Satellite System (GNSS) time and frequency transfer, as well as two-way satellite time and

Catheter ablation is a common treatment for arrhythmia, but can fail if lesion lines are noncontiguous. Identification of gaps and nontransmural lesions can reduce the likelihood of treatment failure and recurrent arrhythmia. Intracardiac myocardial elastography (IME) is a strain imaging technique that provides visualization of the lesion line. Estimation of lesion size and gap resolution were evaluated

We report the time kinetics of fluorescently labeled microbubbles (MBs) in capillary-level microvasculature as measured via confocal microscopy and compare these results to ultrasound localization microscopy (ULM). The observed 19.4 ± 4.2 MBs per confocal field-of-view ( $212\,\,\mu \text{m}\,\,\times 212\,\,\mu \text{m}$ ) are in excellent agreement with the expected count of 19.1 MBs per frame. The

Super-resolution ultrasound (SR-US) imaging is a new technique that breaks the diffraction limit and allows visualization of microvascular structures down to tens of micrometers. The image processing methods for the spatiotemporal filtering needed in SR-US, such as singular value decomposition (SVD), are computationally burdensome and performed offline. Deep learning has been applied to many biomedical

Current methods for in vivo microvascular imaging (<1 mm) are limited by the tradeoffs between the depth of penetration, resolution, and acquisition time. Ultrasound Doppler approaches combined at elevated frequencies (<7.5 MHz) are able to visualize smaller vasculature and, however, are still limited in the segmentation of lower velocity blood flow from moving tissue. Contrast-enhanced ultrasound

Spatial resolution in conventional sonography is achieved through focusing and steering of an ultrasound beam. However, due to acoustic diffraction, the ability to focus an ultrasound beam is limited which leads to low spatial and contrast resolutions. We aim to propose a new method wherein the array elements are simultaneously excited with signals coded with random sequences, which yields an unfocused

Based on a Ba (1–x) Sr x TiO 3 ferroelectric thin film, a discrete tunable surface mounted device (SMD) capacitor has been developed for microwave frequency applications. The proposed SMD topology has the particular advantage of inherent decoupling between the RF signal and the dc biasing voltage, necessary to tune the ferroelectric permittivity. The design and technological development of the SMD

A layered structure combining a thin plate of lithium niobate (LN) with a langasite (LGS) substrate was numerically investigated as an advanced substrate material for surface acoustic wave (SAW) devices with improved characteristics, including capability of operating at high temperatures. The longitudinal leaky SAWs (LLSAWs) propagating with negligible attenuation and high velocities up to 6400 m/s

This article reports on a design journey for Sc x Al 1 – N -based dual-mode hybrid quasi-surface and bulk acoustic wave (quasi-SAW/BAW) resonators. Four types of acoustic excitation configurations are proposed in these designs based on Sc x Al 1–x N/6H-SiC stack architectures. The influence of Sc x Al 1–x N materials, film thickness, and device configurations on the performance is investigated. After

X-ray-induced acoustic computed tomography (XACT) is a promising imaging modality combining high X-ray absorption contrast with the 3-D propagation advantages provided by high-resolution ultrasound waves. The purpose of this study was to optimize the configuration of a 3-D XACT imaging system for bone imaging. A 280 ultrasonic sensors with peak frequency of 10 MHz was designed to distribute on a spherical

Speckle tracking echocardiography (STE) is a clinical tool to noninvasively assess regional myocardial function through the quantification of regional motion and deformation. Even if the time resolution of STE can be improved by high-frame-rate (HFR) imaging, dedicated HFR STE algorithms have to be developed to detect very small interframe motions. Therefore, in this article, we propose a novel 2-D

We report the development of an optically transparent high-frequency ultrasonic transducer using lithium niobate single-crystal and indium–tin–oxide electrodes with up to 90% optical transmission in the visible-to-near-infrared spectrum. The center frequency of the transducer was at 36.9 MHz with 33.9%, at −6 dB fractional bandwidth. The photoacoustic imaging capability of the fabricated transducer