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A Love wave sensor with a phononic parylene-C wave guiding layer is proposed to detect the VEGF secreted during the selective platelet activation process, where arrays of a different material (filling material) are fabricated in the parylene-C films. The effects of the structural design parameters (period width and period number) on the electric response of sensors are investigated. As the period...
Construction of smart city has become a historical trend in the world. The management of underground pipes and the intelligent concrete are the main part of building smart city in China. Compared with the available electronic marker system, SAW-RFID system has shown excellent properties: truly passive, strong penetrating capability, long service-life, sensing and ID integration, and etc. Thus, SAW-RFID...
Diamond has the highest sound velocity among all materials and has been applied in high frequency surface acoustic wave (SAW) devices in the gigahertz range. To date, numerous researches have reported that the SAW devices built on a diamond wafer can work in the frequency range from 2 GHz to 10 GHz. S. Fujii et al. reported that the one-port resonator with an interdigital transducer (IDT)/AlN/single...
In this paper, we describe a 920 MHz band long range wireless SAW passive tag system (WSPTS) for vibration monitoring, which achieves more than 10m reading distance. For the purpose of structural health monitoring (SHM) of aging infrastructures (e.g. bridge, building, and so forth), passive wireless sensor systems are an attractive option because they are operated battery-less and almost maintenance...
Lithium (Li) has long been known to be the best anode material for rechargeable batteries, however, lithium metal batteries (LMB) have never been commercialized due to dendrite formation, resulting in thermal runaway and fire or explosion. During charging, Li ions deposit onto Li anode from the cathode via electrolyte. However, the deposition is not uniform due to the inhomogeneous ion distribution...
In this paper, we fabricated a hybrid on-chip acoustic and field-effect device to investigate the acoustic carrier transportation in graphene. The device fabrication exploited aluminum nitride (AlN)-based surface micromachining process on a silicon wafer, facilitating an integration of a surface acoustic wave (SAW) delay line and a graphene field-effect transistor (GFET). The SAW device induced an...
Based on the least squares method which is arranged to the problem of fitting theoretical to experimental measured variables, such as phase velocities of acoustic waves and/or resonant frequencies, the environment of the minimum sum of squares (SSQ) has been analyzed, similarly to [1]. This is done by forming a “sensitivity matrix” (or Jacobian matrix: derivatives of measured variables with respect...
Coupling between surface acoustic waves (SAW) and arrays of mechanical resonators has appeared early in SAW history as a potential means to slow down wave propagation through mass-loading, in particular by creating corrugations on the substrate surface. This concept has been revisited over the past few years in the context of locally-resonant phononic crystals where pillars deposited on a homogeneous...
Driven by the need for high data-rates and improved cell coverage, mobile phone filters are required to process increasingly high RF power levels. The simultaneous demand for smaller filter footprints makes designing a filter for high-power performance a challenge. We report a method for simulating the self-heating effects of high input powers on a surface acoustic wave (SAW) filter. We also report...
Suppression of the SH-SAW response is mandatory to design TC SAW devices on θ degree rotated Y-cut LiNbO3. However, it is not easy because K2 for SH SAW changes rapidly with θ, and its optimal value in terms of the SH-SAW suppression is dependent on electrode and SiO2 thicknesses. The authors found that the optimal θ always locates close to θ where difference in velocities of two SAWs is minimum....
Acoustic delay lines based on Al0.85Sc0.15N thin film hybrid transducers were investigated by finite element modeling. It was found that an acoustic impedance matching between transducer and non-piezoelectric substrate material plays a crucial role to efficiently excite a traveling surface acoustic wave (SAW) through the BAW piston motion. Test devices based on the 2.5 um thick Al0.85Sc0.15N piezoelectric...
Catheter-delivered ultrasound has been widely utilized for intravascular therapies such as thrombolysis, drug delivery, and plaque removal. High amplitude pressure is required for cavitation induced-microstreaming, which is considered main factor for therapeutic efficiency. Precise spatiotemporal control of insonation is important to relieve concerns on ultrasound-induced damaging of surrounding healthy...
Over the course of accelerated failure testing of 2-port SAW delay line resonators on quartz, periodic acoustomigration damage patterns with acoustic apertures of less than 6 wavelengths were observed across the fully metalized region between the transducers, while typical electrode stress damage was observed over the acoustic aperture in the transducer gratings. This suggested the power density had...
Recently, contactless manipulation of immersed objects has garnered great interest. Specifically, acoustic manipulation in microfluidic channels has emerged as a tool to control micron-sized objects in chemical, medical, and biological applications. Pure and controllable acoustic forces of the acoustic manipulation method exhibit a minor negative impact on viability and functionality of biological...
Surface acoustic waves (SAW) are used to study structural changes induced by electric and weak magnetic fields in the nematic liquid crystal (6CHBT) doped with low concentration (1×10−3, 1×10−4, 1×10−5) of carbon nanotubes, both single-walled (SWCNT), multi-walled (MWCNT) and functionalized with Fe3O4 particles. The role of temperature, concentration and functionalization on structural changes was...
It is crucial to transport foreign substance into living cells efficiently and minimize adverse side-effects. Using ultrasound microbubble, it is possible to enhance the cellular uptake and transfer the extracellular molecules into cells, this process is called sonoporation. However, the spatial location of microbubbles appears to be a stochastic process, which makes the targeted sonoporation at specific...
Recently, it was shown that heavily doped AlN film possess the high piezoelectricity by Akiyama et al [1]. On the other hand, SAW devices were widely used as filters and sensors. Among them, SAW in ScAlN film is attracting a lot of attention because this SAW devices have high electromechanical coupling coefficient K2. We analyzed the K2 value in Sc0.4Al0.6N was increased by c-axis tilted angle θ becoming...
A general purpose finite element model that yielded directly the nonlinear frequency response of the second harmonic generation in SAW IDT resonators was developed. The model enabled us to study the effects of the nonlinear material constants, voltage drive, duty factor, and IDT geometry on f-2f nonlinear interactions. Specifically we have applied our model to the study of nonlinear frequency response...
I.H.P. SAW (Incredible High-Performance SAW) has a novel multi-layered structure to confine SAW energy in substrate surface area, and it shows extremely high quality (Q) factor, low temperature coefficient of frequency (TCF) and improved electromechanical coupling coefficient (K2). This paper introduces its mechanism of the high acoustic Q factor, both theoretically and experimentally, and its applications...
Analog signal processing techniques based on surface acoustic wave (SAW) devices have been commercialized in the past 50 years. Delay lines [1] and resonators [2] have been implemented for a wide range of applications [3]. The use of small scale resonators has boomed because of the continuous growth of the cell phone business, whereas components such as delay lines have been relegated to smaller markets...
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