The Experts below are selected from a list of 147663 Experts worldwide ranked by ideXlab platform
Haosu Luo - One of the best experts on this subject based on the ideXlab platform.
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lead free piezoelectric single crystal based 1 3 composites for ultrasonic Transducer applications
Sensors and Actuators A-physical, 2012Co-Authors: Dan Zhou, Qinhui Zhang, Haosu Luo, Kwok Ho Lam, Yan Chen, Yat Ching Chiu, Jiyan Dai, Helen Lai Wa ChanAbstract:Abstract In this work, lead-free 1–3 composites based on piezoelectric 0.947Na0.5Bi0.5TiO3–0.053BaTiO3 (NBT–0.053BT) single crystal and epoxy are fabricated for ultrasonic Transducer applications by a modified dice-and-fill method. Excellent properties for ultrasonic Transducer applications have been achieved, such as high electromechanical coupling coefficient (kt = 73%), lower acoustic impedance (Z = 16 MRayl) and moderate dielectric constant. Based on this lead-free piezoelectric single crystal composite, single-element ultrasonic Transducer and linear array have been fabricated and characterized. Both types of Transducers exhibit similar performance with broad bandwidth of exceeding 100%. The promising results show that these lead-free composites have the potential to be used for high-performance ultrasonic Transducers.
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fabrication of angle beam two element ultrasonic Transducers with pmn pt single crystal and pmn pt epoxy 1 3 composite for nde applications
Sensors and Actuators A-physical, 2011Co-Authors: Yaoyao Zhang, Sheng Wang, Daan Liu, Qinhui Zhang, Wei Wang, Bo Ren, Xiangyong Zhao, Haosu LuoAbstract:Abstract The paper describes the fabrication of angle beam two-element prototype ultrasonic Transducers with PMN–PT single crystal and PMN–PT/epoxy 1–3 composite. The optimal designs of Transducers were obtained based on the simulation of PiezoCAD software. A two-layer front matching structure for PMN–PT single crystal Transducer and a one-layer front matching structure for PMN–PT/epoxy 1–3 composite Transducer were selected to match the polyimide slopping block. In the detection on the stainless steel reference block, PMN–PT single crystal and commercial PZT-based 1–3 composite Transducer show similar performances in sensitivity and bandwidth, and PMN–PT/epoxy 1–3 composite Transducer shows the best performances. The two-way insertion loss and bandwidth at −6 dB of the PMN–PT/epoxy 1–3 composite Transducer are −21.3 dB and 94.5%, respectively.
Kirk K Shung - One of the best experts on this subject based on the ideXlab platform.
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eco friendly highly sensitive Transducers based on a new knn ntk fm lead free piezoelectric ceramic for high frequency biomedical ultrasonic imaging applications
IEEE Transactions on Biomedical Engineering, 2019Co-Authors: Ruimin Chen, A Safari, Laiming Jiang, Tianfu Zhang, Takayuki Matsuoka, Masato Yamazaki, Xuejun Qian, Jianguo Zhu, Kirk K Shung, Qifa ZhouAbstract:High-frequency ultrasonic imaging with improved spatial resolution has gained increasing attention in the field of biomedical imaging. Sensitivity of Transducers plays a pivotal role in determining ultrasonic image quality. Conventional ultrasonic Transducers are mostly made from lead-based piezoelectric materials that may be harmful to the human body and the environment. In this study, a new (K,Na)NbO 3 -KTiNbO 5 -BaZrO 3 -Fe 2 O 3 -MgO (KNN-NTK-FM) lead-free piezoelectric ceramic was utilized in developing eco-friendly Transducers for high-frequency biomedical ultrasonic imaging applications. A needle Transducer with a small active aperture size of 0.45 × 0.55 mm 2 was designed and evaluated. The fabricated Transducer exhibits great performance with a high center frequency (52.6 MHz), a good electromechanical coupling (k eff ~ 0.45), a large bandwidth (64.4% at -6 dB), and a very low two-way insertion loss (10.1 dB). Such high sensitivity is superior to those Transducers based on other lead-free piezoelectric materials and can even be comparable to the lead-based ones. Imaging performance of the KNN-NTK-FM needle Transducer was analyzed by imaging a wire phantom and an agar tissue-mimicking phantom. Imaging capabilities of the Transducer were further demonstrated by ex vivo imaging studies on a porcine eyeball and a rabbit aorta. The results suggest that the KNN-NTK-FM piezoceramic has many attractive properties over other lead-free piezoelectric materials in developing eco-friendly highly sensitive Transducers for high-frequency biomedical ultrasonic imaging applications.
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impedance matching network for high frequency ultrasonic Transducer for cellular applications
Ultrasonics, 2016Co-Authors: Min Gon Kim, Sangpil Yoon, Hyung Ham Kim, Kirk K ShungAbstract:An approach for the design of an impedance matching network (IMN) for high frequency ultrasonic Transducers with large apertures based on impedance analysis for cellular applications is presented in this paper. The main objectives were to maximize energy transmission from the excitation source to the ultrasonic Transducers for cell manipulation and to achieve low input parameters for the safe operation of an ultrasonic Transducer because the piezoelectric material in high frequency ultrasonic Transducers is prone to breakage due to its being extremely thin. Two ultrasonic Transducers, which were made of lithium niobate single crystal with the thickness of 15 μm, having apertures of 4.3 mm (fnumber=1.23) and 2.6mm (fnumber=0.75) were tested. L-type IMN was selected for high sensitivity and compact design of the ultrasonic Transducers. The target center frequency was chosen as the frequency where the electrical admittance (|Y|) and phase angle (θz) from impedance analysis was maximal and zero, respectively. The reference center frequency and reference echo magnitude were selected as the center frequency and echo magnitude, measured by pulse-echo testing, of the ultrasonic Transducer without IMN. Initial component values and topology of IMN were determined using the Smith chart, and pulse-echo testing was analyzed to verify the performance of the ultrasonic Transducers with and without IMN. After several iterations between changing component values and topology of IMN, and pulse-echo measurement of the ultrasonic Transducer with IMN, optimized component values and topology of IMN were chosen when the measured center frequency from pulse-echo testing was comparable to the target frequency, and the measured echo magnitude was at least 30% larger than the reference echo magnitude. Performance of an ultrasonic Transducer with and without IMN was tested by observing a tangible dent on the surface of a plastic petridish and single cell response after an acoustic pulse was applied on a target cell.
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piezoelectric single crystal ultrasonic Transducers for biomedical applications
Progress in Materials Science, 2014Co-Authors: Qifa Zhou, Kwok Ho Lam, Hairong Zheng, Weibao Qiu, Kirk K ShungAbstract:Abstract Piezoelectric single crystals, which have excellent piezoelectric properties, have extensively been employed for various sensors and actuators applications. In this paper, the state-of-art in piezoelectric single crystals for ultrasonic Transducer applications is reviewed. Firstly, the basic principles and design considerations of piezoelectric ultrasonic Transducers will be addressed. Then, the popular piezoelectric single crystals used for ultrasonic Transducer applications, including LiNbO 3 (LN), PMN–PT and PIN–PMN–PT, will be introduced. After describing the preparation and performance of the single crystals, the recent development of both the single-element and array Transducers fabricated using the single crystals will be presented. Finally, various biomedical applications including eye imaging, intravascular imaging, blood flow measurement, photoacoustic imaging and microbeam applications of the single crystal Transducers will be discussed.
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piezoceramics for high frequency 20 to 100 mhz single element imaging Transducers
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 1997Co-Authors: M J Zipparo, Kirk K Shung, T R ShroutAbstract:The performance of Transducers operating at high frequencies is greatly influenced by the properties of the piezoelectric materials used in their fabrication. Selection of an appropriate material for a Transducer is based on many factors, including material properties, Transducer area, and operating frequency. The properties of a number of piezoceramic materials have been experimentally determined by measuring the electrical impedance of air-loaded resonators whose thickness corresponds to resonance frequencies from 10 to 100 MHz. Materials measured include commercially available compositions of lead zirconate titanate (PZT) with relatively high dielectric constants and a modified lead titanate (PT) composition with a much lower dielectric constant. In addition, materials which have been designed or modified to result in improved properties at high frequencies are studied. Conclusions concerning the influence of the microstructure and composition on the frequency dependence of the material properties are made from the calculated properties and microstructural analysis of each material. Issues which affect Transducer performance are discussed in relation to the properties. For Transducers larger than about 1 mm in diameter, the use of a lower dielectric constant material is shown to result in a better electrical match between the Transducer and a standard 50 /spl Omega/ termination. For Transducers whose impedance is close to that of the connecting cables and electrical termination, equivalent circuit model simulations show improved performance without the need for electrical matching networks. Measurements of fabricated Transducers show close agreement with the simulations, validating the measurements and showing the performance benefits of electrically matched Transducers.
Kwok Ho Lam - One of the best experts on this subject based on the ideXlab platform.
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piezoelectric single crystal ultrasonic Transducers for biomedical applications
Progress in Materials Science, 2014Co-Authors: Qifa Zhou, Kwok Ho Lam, Hairong Zheng, Weibao Qiu, Kirk K ShungAbstract:Abstract Piezoelectric single crystals, which have excellent piezoelectric properties, have extensively been employed for various sensors and actuators applications. In this paper, the state-of-art in piezoelectric single crystals for ultrasonic Transducer applications is reviewed. Firstly, the basic principles and design considerations of piezoelectric ultrasonic Transducers will be addressed. Then, the popular piezoelectric single crystals used for ultrasonic Transducer applications, including LiNbO 3 (LN), PMN–PT and PIN–PMN–PT, will be introduced. After describing the preparation and performance of the single crystals, the recent development of both the single-element and array Transducers fabricated using the single crystals will be presented. Finally, various biomedical applications including eye imaging, intravascular imaging, blood flow measurement, photoacoustic imaging and microbeam applications of the single crystal Transducers will be discussed.
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ultrahigh frequency lensless ultrasonic Transducers for acoustic tweezers application
Biotechnology and Bioengineering, 2013Co-Authors: Kwok Ho Lam, Qifa Zhou, Hsiusheng Hsu, Changyang Lee, Anderson Lin, Eun Sok Kim, K K ShungAbstract:Similar to optical tweezers, a tightly focused ultrasound microbeam is needed to manipulate microparticles in acoustic tweezers. The development of highly sensitive ultrahigh frequency ultrasonic Transducers is crucial for trapping particles or cells with a size of a few microns. As an extra lens would cause excessive attenuation at ultrahigh frequencies, two types of 200-MHz lensless Transducer design were developed as an ultrasound microbeam device for acoustic tweezers application. Lithium niobate single crystal press-focused (PF) Transducer and zinc oxide self-focused Transducer were designed, fabricated and characterized. Tightly focused acoustic beams produced by these Transducers were shown to be capable of manipulating single microspheres as small as 5 μm two-dimensionally within a range of hundreds of micrometers in distilled water. The size of the trapped microspheres is the smallest ever reported in the literature of acoustic PF devices. These results suggest that these lensless ultrahigh frequency ultrasonic Transducers are capable of manipulating particles at the cellular level and that acoustic tweezers may be a useful tool to manipulate a single cell or molecule for a wide range of biomedical applications.
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lead free piezoelectric single crystal based 1 3 composites for ultrasonic Transducer applications
Sensors and Actuators A-physical, 2012Co-Authors: Dan Zhou, Qinhui Zhang, Haosu Luo, Kwok Ho Lam, Yan Chen, Yat Ching Chiu, Jiyan Dai, Helen Lai Wa ChanAbstract:Abstract In this work, lead-free 1–3 composites based on piezoelectric 0.947Na0.5Bi0.5TiO3–0.053BaTiO3 (NBT–0.053BT) single crystal and epoxy are fabricated for ultrasonic Transducer applications by a modified dice-and-fill method. Excellent properties for ultrasonic Transducer applications have been achieved, such as high electromechanical coupling coefficient (kt = 73%), lower acoustic impedance (Z = 16 MRayl) and moderate dielectric constant. Based on this lead-free piezoelectric single crystal composite, single-element ultrasonic Transducer and linear array have been fabricated and characterized. Both types of Transducers exhibit similar performance with broad bandwidth of exceeding 100%. The promising results show that these lead-free composites have the potential to be used for high-performance ultrasonic Transducers.
Qifa Zhou - One of the best experts on this subject based on the ideXlab platform.
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eco friendly highly sensitive Transducers based on a new knn ntk fm lead free piezoelectric ceramic for high frequency biomedical ultrasonic imaging applications
IEEE Transactions on Biomedical Engineering, 2019Co-Authors: Ruimin Chen, A Safari, Laiming Jiang, Tianfu Zhang, Takayuki Matsuoka, Masato Yamazaki, Xuejun Qian, Jianguo Zhu, Kirk K Shung, Qifa ZhouAbstract:High-frequency ultrasonic imaging with improved spatial resolution has gained increasing attention in the field of biomedical imaging. Sensitivity of Transducers plays a pivotal role in determining ultrasonic image quality. Conventional ultrasonic Transducers are mostly made from lead-based piezoelectric materials that may be harmful to the human body and the environment. In this study, a new (K,Na)NbO 3 -KTiNbO 5 -BaZrO 3 -Fe 2 O 3 -MgO (KNN-NTK-FM) lead-free piezoelectric ceramic was utilized in developing eco-friendly Transducers for high-frequency biomedical ultrasonic imaging applications. A needle Transducer with a small active aperture size of 0.45 × 0.55 mm 2 was designed and evaluated. The fabricated Transducer exhibits great performance with a high center frequency (52.6 MHz), a good electromechanical coupling (k eff ~ 0.45), a large bandwidth (64.4% at -6 dB), and a very low two-way insertion loss (10.1 dB). Such high sensitivity is superior to those Transducers based on other lead-free piezoelectric materials and can even be comparable to the lead-based ones. Imaging performance of the KNN-NTK-FM needle Transducer was analyzed by imaging a wire phantom and an agar tissue-mimicking phantom. Imaging capabilities of the Transducer were further demonstrated by ex vivo imaging studies on a porcine eyeball and a rabbit aorta. The results suggest that the KNN-NTK-FM piezoceramic has many attractive properties over other lead-free piezoelectric materials in developing eco-friendly highly sensitive Transducers for high-frequency biomedical ultrasonic imaging applications.
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piezoelectric single crystal ultrasonic Transducers for biomedical applications
Progress in Materials Science, 2014Co-Authors: Qifa Zhou, Kwok Ho Lam, Hairong Zheng, Weibao Qiu, Kirk K ShungAbstract:Abstract Piezoelectric single crystals, which have excellent piezoelectric properties, have extensively been employed for various sensors and actuators applications. In this paper, the state-of-art in piezoelectric single crystals for ultrasonic Transducer applications is reviewed. Firstly, the basic principles and design considerations of piezoelectric ultrasonic Transducers will be addressed. Then, the popular piezoelectric single crystals used for ultrasonic Transducer applications, including LiNbO 3 (LN), PMN–PT and PIN–PMN–PT, will be introduced. After describing the preparation and performance of the single crystals, the recent development of both the single-element and array Transducers fabricated using the single crystals will be presented. Finally, various biomedical applications including eye imaging, intravascular imaging, blood flow measurement, photoacoustic imaging and microbeam applications of the single crystal Transducers will be discussed.
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ultrahigh frequency lensless ultrasonic Transducers for acoustic tweezers application
Biotechnology and Bioengineering, 2013Co-Authors: Kwok Ho Lam, Qifa Zhou, Hsiusheng Hsu, Changyang Lee, Anderson Lin, Eun Sok Kim, K K ShungAbstract:Similar to optical tweezers, a tightly focused ultrasound microbeam is needed to manipulate microparticles in acoustic tweezers. The development of highly sensitive ultrahigh frequency ultrasonic Transducers is crucial for trapping particles or cells with a size of a few microns. As an extra lens would cause excessive attenuation at ultrahigh frequencies, two types of 200-MHz lensless Transducer design were developed as an ultrasound microbeam device for acoustic tweezers application. Lithium niobate single crystal press-focused (PF) Transducer and zinc oxide self-focused Transducer were designed, fabricated and characterized. Tightly focused acoustic beams produced by these Transducers were shown to be capable of manipulating single microspheres as small as 5 μm two-dimensionally within a range of hundreds of micrometers in distilled water. The size of the trapped microspheres is the smallest ever reported in the literature of acoustic PF devices. These results suggest that these lensless ultrahigh frequency ultrasonic Transducers are capable of manipulating particles at the cellular level and that acoustic tweezers may be a useful tool to manipulate a single cell or molecule for a wide range of biomedical applications.
Qinhui Zhang - One of the best experts on this subject based on the ideXlab platform.
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lead free piezoelectric single crystal based 1 3 composites for ultrasonic Transducer applications
Sensors and Actuators A-physical, 2012Co-Authors: Dan Zhou, Qinhui Zhang, Haosu Luo, Kwok Ho Lam, Yan Chen, Yat Ching Chiu, Jiyan Dai, Helen Lai Wa ChanAbstract:Abstract In this work, lead-free 1–3 composites based on piezoelectric 0.947Na0.5Bi0.5TiO3–0.053BaTiO3 (NBT–0.053BT) single crystal and epoxy are fabricated for ultrasonic Transducer applications by a modified dice-and-fill method. Excellent properties for ultrasonic Transducer applications have been achieved, such as high electromechanical coupling coefficient (kt = 73%), lower acoustic impedance (Z = 16 MRayl) and moderate dielectric constant. Based on this lead-free piezoelectric single crystal composite, single-element ultrasonic Transducer and linear array have been fabricated and characterized. Both types of Transducers exhibit similar performance with broad bandwidth of exceeding 100%. The promising results show that these lead-free composites have the potential to be used for high-performance ultrasonic Transducers.
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fabrication of angle beam two element ultrasonic Transducers with pmn pt single crystal and pmn pt epoxy 1 3 composite for nde applications
Sensors and Actuators A-physical, 2011Co-Authors: Yaoyao Zhang, Sheng Wang, Daan Liu, Qinhui Zhang, Wei Wang, Bo Ren, Xiangyong Zhao, Haosu LuoAbstract:Abstract The paper describes the fabrication of angle beam two-element prototype ultrasonic Transducers with PMN–PT single crystal and PMN–PT/epoxy 1–3 composite. The optimal designs of Transducers were obtained based on the simulation of PiezoCAD software. A two-layer front matching structure for PMN–PT single crystal Transducer and a one-layer front matching structure for PMN–PT/epoxy 1–3 composite Transducer were selected to match the polyimide slopping block. In the detection on the stainless steel reference block, PMN–PT single crystal and commercial PZT-based 1–3 composite Transducer show similar performances in sensitivity and bandwidth, and PMN–PT/epoxy 1–3 composite Transducer shows the best performances. The two-way insertion loss and bandwidth at −6 dB of the PMN–PT/epoxy 1–3 composite Transducer are −21.3 dB and 94.5%, respectively.
