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Based on the fundamental piezoelastic theory, the vibration equation of layered FBAR under sine excitation voltage was derived. The unknown constants were calculated with boundary and continuity conditions. The expressions of electrical impedance were obtained from the electrical potential and current. The series and parallel resonance frequency are then calculated when the electrical impedance tends...
Suspended particles are a general term for solid and the liquid particulate matter suspended in the atmosphere. Total suspended particles in air quality evaluation are an important general pollution index. This paper aims to find a simple acoustic method to measure the volume of the total suspended particles. In order to measure the volume fraction of suspended particulate matter in the air, we studied...
This paper describes the thermal tuning of acoustic transmission enhancement through a phononic crystal slab (PCS), which is formed by ferroelectric ceramic Ba0.7Sr0.3TiO3 (BST) slab patterned with periodical array of rectangular gratings on one side. We theoretically investigate the normal incident transmission spectrum of the PCS in the temperature of 35°C and 45°C respectively, which are across...
In this work, Flynn's formulation is adopted to analyze the dynamics, temperature and pressure of the cavitation bubble in the room-temperature liquids (RTIL) because of their unique physical properties. The effects of the ultrasonic intensity, frequency and the initial radius of the bubble on the cavitation process are studied, and the temperature and pressure in the collapsing bubbles are also analyzed...
Spacecraft's wing surface just like wing, solar panel, satellite antenna and so on can have local high temperature because of high-speed friction with the air of atmosphere and solar radiation in outer space, while upper atmosphere or outer space that light can not strikes have low temperature. Because of these, the wing surface's local stiffness, surface shape and vibration characteristic of mode...
The immobilization of cancer antigens onto the surface of piezoelectric immunosensor by a novel method was presented and evaluated for its potential use in early cancer detection. A 3rd overtone 10MHz AT-cut quartz crystal resonator was applied to detect the antibody of NuTu-19 ovarian cancer cell in serum samples using this novel immobilization method. The NuTu-19 ovarian cancer cells were planted...
Among various manipulation methods, acoustic manipulation has some advantages including penetrability, non-contact and versatility, without any biochemical decorations to particles. Recently, we have theoretically demonstrated that phononic crystal slab (PCS) can generate periodically gradient field near the surface, which can be used for trapping particles. In this letter, we experimentally realize...
The impacts of two immobilization methods, which are Biotin-avidin system (BAS) and Self-assembled monolayer technology (SAM), made on the performance of aptasensors in terms of acoustics were analyzed through experiment. Love-wave aptasensors were designed by coupling aptamers to the surface of a Love-wave sensor with the two methods respectively. Abrin is chosen as the analyte. For certain concentrations...
This paper aimed to study the pressure sensitive coefficients of different cuts of quartz for the surface acoustic wave(SAW) pressure sensors with non-uniform pressure load, and tried to find the most sensitive cut. The finite element analysis/ perturbation theory combines model was constructed to calculate the pressure sensitive coefficients. For analysis of different cut angles (0, θ, φ) of quartz...
Based on the complex variable method, we anaylzed the two-dimensional problems of an electrostrictive solid with two circular holes. The solid is subjected to electric field at infinity. The complex potentials of electric and electroelastic fields were first expressed by introducing series expansion with unknown coefficients. Then, using the boundary condition, we can calculate the unknown coefficients,...
Exact solutions in elementary functions are derived for the stress and electric displacement intensity factors of a penny-shaped crack in a transversely isotropic piezoelectric space interacting with various stress and charge sources: force dipoles, electric dipoles and moments. Locations and orientations of these resultant sources with respect to the crack are arbitrary. Such stress and charge sources...
In this paper, a novel self-sensing smart tool was proposed and designed for monitoring cutting force in ultra-precision machining, which integrate the sensors using piezoelectric films. The special designed insert tool has been presented, which has two small and special stress cavity structures so as to improve the measure sensitivity. The FE-model of smart tool was established and structural mechanics...
Based on linear piezoelectric and elastic theory, axisymmetric wave propagation along the piezoelectric layered composite cylinder is analyzed and the dispersion equation is derived by subjecting general solutions to specific boundary and continuity conditions. The existence of both axial and radial interfacial imperfections is considered using a linear spring model. It is found that the behaviors...
In this paper, we study the band gap properties of two-dimensional piezoelectric phononic crystals with {1-3} connectivity family, in which piezoelectric rods with a square cross-section are embedded in a polymer matrix in a square lattice. The finite element method is applied to calculate the band structures of two polarization modes: the shear mode out-of-plane and the mixed mode in-plane. The effects...
To research on the mechanism of non-resonant linear piezoelectric motors, longitudinal vibration model and pseudo-rigid-body model were established for the stator of motor through the analysis of the construction and operating process of the motor. Then the longitudinal vibration differential equation and transverse vibration differential equation of the drive tip were produced. Thus longitudinal...
To evaluate the sound field characteristic of ultrasonic diagnostic and therapy equipment and industrial ultrasonic transducer, ultrasonic hydrophone such as needle-type hydrophone, membrane hydrophone and fiber optic hydrophone are always needed. The needle-type hydrophone has been widely used for its property of small size, high signal to noise ratio, good directivity, wide frequency response, ability...
The piezoelectric thin film bulk acoustic resonators (FBARs) is a new kind frequency devices, which has exhibited several prominent advantages. In this paper, the typical models of FBAR are established to analyze modal resonance frequency with ANSYS codes. The results for the modal resonance frequencies vs. width-to-thickness aspect ratio were obtained. The effective electro-mechanical coupling factors...
An additional middle elastic layer is considered between input and output portions in a piezoelectric plate transformer due to interface bonding glue possibly used excessively. A theoretical solution of thickness-shear modes is obtained to investigate the effect of the middle layer on the piezoelectric transformer. An examination of the numerical results demonstrates that the addition of middle layer...
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