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[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - High Voltage Excitation and Nonlinear Transmission of a 16 MHz AlN-Based Piezoelectric Micro-Machined Ultrasonic Transducer
摘要： This paper reports the performance of a 25 μm AlGaN-based micro-piezoelectric transducer (MPT) under high voltage excitation and determination. The proposed MPT array consists of 23×28 elements fabricated on a silicon-on-insulator (SOI) substrate with 1 μm AlGaN thin film on 24 μm silicon membrane. With all the array elements electrically connected together, the electric impedance of the MPT was 11.5–7.22 kΩ at 24.7 MHz resonance frequency in air and 3.21–7.24 kΩ at 22.8 MHz when the device was water charged. The laser Doppler vibrometer (LDV) measurements showed that the transmission efficiency and the bandwidth for free vibration were 1.6 nm/V and 1.0%, respectively. The resonance modes were specifically associated with the material parameters and the initial state of the device. Moreover, nonlinear behavior was observed when increasing the input mean power exceeded 24 mW. This strategy is potentially applied to CMOS-compatible high-resolution ultrasound imaging.
关键词： AlGaN,CMOS-compatible,Ultrasound,High voltage,Micro-piezoelectric transducer
更新于2025-09-23 15:22:29
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Monitoring of the Ceramic Kerf During the Laser Cutting Process through Piezoelectric Transducer
摘要： Advanced ceramics are widely used in industry due to their unique properties. However, the machining of ceramic components by conventional methods is difficult due to their high level of hardness and brittleness. In this sense, laser beam machining (LBM) is presented as an alternative to conventional methods, enabling the machining of workpieces through more accurate and less invasive techniques. Despite the advantages of laser machining, the process still needs to be studied in detail, as advanced ceramic machining is considered a stochastic process. Thus, real-time monitoring systems are required in order to optimize the ceramic laser machining. Therefore, this paper proposes a novel method for monitoring the cutting kerf in the laser cutting process of ceramic components using a low-cost piezoelectric transducer (PZT) and digital signal processing. Tests were performed on the surface of an alumina ceramic workpiece under different machining conditions. The cutting kerf was measured by a digital microscope and the raw signals from the PZT transducer were collected at a sampling rate of 2 MHz. Time domain and frequency domain analyses were performed in order to find a frequency band that best correlates with the process conditions. Finally, a linear regression was calculated in order to correlate the PZT signal and the measured kerf. The results showed that the piezoelectric transducer was sensitive to the acoustic activity generated during the process, allowing the real-time monitoring of the cutting kerf. Thus, the approach proposed in this paper can be used efficiently in the monitoring of the laser cutting process.
关键词： monitoring,digital signal processing,ceramic,laser machining,piezoelectric transducer
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - Design, Fabrication and Characterization of a Hybrid Piezoelectric-CMUT Dual-Frequency Ultrasonic Transducer
摘要： Dual-frequency band imaging and characterization of a hybrid structure consisting of a piezoelectric transducer and a quantum well infrared photodetector (QWIP) are presented. The hybrid structure, i.e., a single-element QWIP placed on top of a piezoelectric transducer, may be conveniently used in different imaging applications such as in harmonic imaging, where it can be used to increase the resolution of the imaging system. In this paper, the design and fabrication of a dual-frequency band hybrid transducer, i.e., a single-element QWIP placed on top of a piezoelectric transducer, is presented. The low-frequency (LF) transducer, i.e., a single-element piezoelectric transducer, is designed for operation around 1 MHz in immersion, while the high-frequency (HF) transducer, i.e., a single-element QWIP, is designed for operation around 20 MHz in immersion. The three transducer prototypes were electrically and acoustically characterized. Characterization results were compared with simulations showing that the proposed hybrid transducer may be conveniently used in non-linear imaging applications such as in harmonic imaging, where it can be used to increase the resolution of the imaging system.
关键词： Harmonic imaging,Hybrid transducer,Dual-frequency band imaging,QWIP,Acoustic characterization,Piezoelectric transducer
更新于2025-09-19 17:15:36
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[IEEE 2019 IEEE International Conference on Sensors and Nanotechnology (SENSORS & NANO) - Penang, Malaysia (2019.7.24-2019.7.25)] 2019 IEEE International Conference on Sensors and Nanotechnology - Effect of Laser Power on the Formation of Porous Graphitic Carbon on Polyimide Film
摘要： This paper proposes a new linear ultrasonic motor using hybrid mode of the first symmetric and anti-symmetric longitudinal modes. The stator is constructed by two Langevin transducers in combination with two isosceles triangular beams. The triangular beams can transform the displacement in axial direction into the displacement in perpendicular direction and generate the oval trajectory of the driving foot, which is the merit of the simple structure. For better mode degeneration result, the influence of the triangular beam dimensions on the vibration frequency difference of the stator was analyzed by Finite Element Method (FEM) analysis. The overall dimensions of the prototype stator are 70 mm (length) × 15 mm (width) × 10 mm (thickness). Driven by ac signals with the driving frequency of 55 kHz and voltage 400 Vp?p, the motor can provide the no-load speed 63.87 mm/s and maximum thrust force 3.14 N, respectively. The frequency matching process of ultrasonic motor is simplified by adjusting the structure dimensions of the triangular beams.
关键词： Ultrasonic motor,piezoelectric transducer,hybrid mode.
更新于2025-09-19 17:13:59
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[IEEE 2019 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Saint-Petersburg, Russia (2019.6.3-2019.6.7)] 2019 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Electronic Retuning of Acousto-Optic Laser Mode Locker. Experimental study
摘要： The effect of electronic retuning of acoustic resonances in an acousto-optic laser mode locker is investigated theoretically and experimentally. In the approximation of plane acoustic waves, the problem of excitation of the Fabry–Perot acoustic resonator by a plate piezoelectric transducer is solved with taking into account real parameters of a RF generator and matching elements. The resonances were retuned by changing reactive matching elements (inductance coil and capacitor) connected between the generator and the transducer. In the experiment, an acousto-optic cell made of crystalline quartz with a two-sectional lithium niobate transducer was used.
关键词： acoustic Fabry–Perot resonator,piezoelectric transducer,acousto-optic modulator,acousto-optic interaction,laser mode locking
更新于2025-09-11 14:15:04
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[IEEE 2018 Days on Diffraction (DD) - St.Petersburg, Russia (2018.6.4-2018.6.8)] 2018 Days on Diffraction (DD) - Semi-analytical hybrid approach for modelling wave motion excited by a piezoelectric transducer in periodic layered composite with a crack
摘要： The paper presents a semi-analytical hybrid approach for modelling the interaction of a piezoelectric transducer and with a periodic elastic structure with a crack. It combines advantages of the frequency domain spectral element method using Gauss–Legendre–Lobatto polynomials and the boundary integral approach. The unknown crack-opening-displacement and the traction vector in the contact area are determined via Galerkin method.
关键词： semi-analytical hybrid approach,frequency domain spectral element method,Galerkin method,periodic elastic structure,boundary integral approach,piezoelectric transducer,crack
更新于2025-09-09 09:28:46
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[ASME ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems - San Antonio, Texas, USA (Monday 10 September 2018)] Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation - Ultrasonic Piezoelectric Atomizers: Electromechanical Modeling and Performance Testing
摘要： Ultrasonic atomization of bulk liquids has received extensive attention in the past few decades due to the ability to produce controlled droplet sizes, a necessity for many industries such as spray coating and aerosol drug delivery. Despite the increase in attention, one novel application of this technology has been overlooked until recently, and that is the moisture removal capabilities of atomization. The first ever ultrasonic dryer, created by researchers at Oak Ridge National Lab in 2016, applies the mechanisms of atomization to mechanically remove moisture from clothing. The process utilizes the ultrasonic vibrations created by a piezoelectric transducer in direct contact with a wet fabric to rupture the liquid-vapor boundary of the retained water. Once ruptured, smaller droplets are ejected from the bulk liquid and are actively removed from the fabric pores. The mechanisms of droplet ejection from this event are related to both capillary waves forming on the liquid surface (Capillary Wave Theory), as well as the implosion of cavitation bubbles formed from the hydraulic shocks propagating from the transducer (Cavitation Theory). In this work, we present an analytical model for predicting the moisture removal rate of a wet fabric exposed to ultrasonic vibrations, and connect the atomization events to a global variable, acceleration, in order to decouple the relationship between the transducer and applied voltage. The acceleration governing atomization is predicted using a verified numerical model. The numerical model is shown to assist in developing ultrasonic drying by means of efficiently evaluating transducer design changes.
关键词： moisture removal,cavitation theory,piezoelectric transducer,capillary wave theory,Ultrasonic atomization
更新于2025-09-09 09:28:46