marc lukacs - Academia.edu (original) (raw)
Papers by marc lukacs
MRS Proceedings, 1997
The analytical solution of the wave equation for a piezoelectric layer supported by a substrate i... more The analytical solution of the wave equation for a piezoelectric layer supported by a substrate is presented. Using the appropriate boundary conditions, the impedance for a piezoelectric layer driven in the thickness axis is derived and expressed in terms of the mechanical, electrical and piezoelectrical properties of the two materials. This solution allows for the extension of the free resonator IEEE impedance techniques and provides a nondestructive method for determining the material parameters of a piezoelectric film with mechanical support. The validity and universality of the model is demonstrated by measurements on composite sol gel PZT coatings within the thickness range of 15-70lm on aluminum substrates of varying thickness, and by simulating the mass loading of a quartz thickness resonator.
Ultrasound in Medicine and Biology, Oct 1, 2009
Most institutions now have a suite of imaging tools to follow mouse models of human disease. Micr... more Most institutions now have a suite of imaging tools to follow mouse models of human disease. Microultrasound is one of these tools and is second after whole-mouse fluorescence or bioluminescent imaging, in terms of installed systems. We report in this paper the first commercially available array transducer-based ultrasound imaging system that enables micro-ultrasound imaging at center frequencies between 15 and 50 MHz. At the heart of the new scanner is a laser-machined high-frequency 256 element, linear transducer array capable of forming dynamic diffraction limited beams. The power of the linear array approach is embodied in the uniform high resolution maintained over the full field of view. This leads to greatly expanded scope for real-time functional imaging that is demonstrated in this paper. The unprecedented images made with the new imaging system will enable many new applications not previously possible. These include real-time visualization of flow in the mouse placenta, visualization of flow development in the embryo, studies of embryonic to adult cardiac development/disease, and studies of real-time blood flow in mouse models of tumour angiogenesis.
Ultra-Fine Piezoelectric Composites For High Frequency
This paper presents a new technique called interdigital phase bonding (IPhB) that has been develo... more This paper presents a new technique called interdigital phase bonding (IPhB) that has been developed to make 2-2 PZT composites of ultra-fine pitch for use as transducers and arrays operating at frequencies >30 MHz. By using the IPhB method, a composite structure with a pitch that is less than the dicing saw blade thickness can be created. The flexibility of
Proceedings of SPIE, Jul 15, 1999
ABSTRACT
Design and Fabrication of Ultrafine Piezoelectric Composites
Ultrasonic Imaging, 2005
Making fine scale (< 20 microm) piezoelectric composites for high frequency (> 50 M... more Making fine scale (< 20 microm) piezoelectric composites for high frequency (> 50 MHz) ultrasound transducers remains challenging. Interdigital phase bonding (IPhB), described in this paper, presents a new technique developed to make piezoelectric composites at the ultrafine scale using a conventional dicing saw. Using the IPhB technique, a composite structure with a pitch that is less than the dicing saw blade thickness can be created. The approach is flexible enough to make composites of different combination of pitch and volume ratio. Using a conventional dicing saw with a 50 microm thick blade, composite with a 25 microm pitch and a volume ratio of 61 percent are fabricated. Such a composite is suitable for fabrication of ultrasonic transducers and arrays with central frequencies of up to 85 MHz. Single element transducers working at central frequencies of 50-60 MHz were made of these composites as a mean to characterize the acoustic performance. Measurement results of the transducers show that the longitudinal electromechanical coupling coefficient is greater than 0.6 and that there are no noticeable lateral resonances in the frequency range of 55-150 MHz. Design criteria for fine scale elements are also discussed based on theoretical results from finite element analysis (FEA).
Proceedings of SPIE, May 1, 1998
Ceramic ultrasonic transducers with a frequency response <50MHz using lead zirconate titanate ... more Ceramic ultrasonic transducers with a frequency response <50MHz using lead zirconate titanate (PZT) layers in the 5-4Otm range have been difficult to achieve by bulk or thin film techniques. Advances in the production of small sized PZT ceramic powder allow the development ofthinner ceramic layers for this application. Sol gel composite thin film technology also provides a new technique for producing ceramic coatings of a thickness that successfully bridges the gap between traditional thin film and bulk techniques. So! gel composite PZT layers of 5-7Om have been coated on substrates (aluminum, platinized silicon, stainless steel, .. .) that can withstand the thermal processing of the ceramic. The thickness mode response of a thin piezoelectric layer supported by a thick substrate has been modeled from first principles using complex material constants. The LevenbergMarquart non linear regression technique has been used to extract the thickness mode elastic stiffness, dielectric constant and piezoelectric constant of the PZT, and the elastic stiffness of the substrate from the layered structure. This non-destructive technique allows for a reliable assessment of the quality of a coating prior to the fabrication of a transducer. The elastic stiffness of the substrate is not lossy enough for the required broadband response of an imaging transducer. However, aluminum can be preferentially etched, releasing the ceramic coating. Therefore it is possible to transfer the PZT film to a more suitable backing material. A processing sequence for single element PZT transducers in the frequency range of 50-200MHz has been developed. Characterization of transducers has been performed using pulse-echo techniques and by creating real time B-scan images of agar phantoms and biological tissue. Methods for patterning the PZT composite coatings are being developed with the intent to fabricate a linear array in the 40-60 MHz frequency range. Due to the very fine patterning and high concentration of cuts required for a high aspect ratio linear array, the limits of conventional etching techniques are surpassed. Laser micromachining using a frequency doubled Nd:YAG and a KrF excimer laser have the ability to pattern the array structure. In both cases, laser cuts <1Om wide have been achieved.
Thickness mode material constants of a supported piezoelectric film
Journal of Applied Physics, Mar 1, 1999
New thick film ceramic processing techniques and microelectromechanical systems require material ... more New thick film ceramic processing techniques and microelectromechanical systems require material characterization of a piezoelectric film supported by a substrate. An analytical solution of the one-dimensional wave equation for multiple layered systems driven in the thickness mode is presented. The impedance across the piezoelectric layer is derived and expressed in terms of the material properties of the two materials. This includes the open-circuit elastic stiffness c33D, the clamped permittivity ε33S and the h33 piezoelectric constant of the piezoelectric layer and the elastic stiffness csD of the substrate. The properties are expressed as complex variables in order to account for the losses within the materials. The material parameters of the solution are extracted from experimental results using a modified Levenberg–Marquardt technique. The capabilities of this nondestructive technique are demonstrated using experimental and simulated impedance spectra of lead zirconium titanate sol gel composite coatings within the thickness range of 15–70 μm on aluminum and on platinum electroded silicon substrates and by simulating the mass loading of a quartz thickness resonator. The analytical solution allows for the extension of the Institute of Electrical and Electronics Engineers free resonator impedance technique to supported films and provides a method for determining the material parameters of a piezoelectric coating.
Hybrid dual frequency transducer and Scanhead for micro-ultrasound imaging
Abstract We report on the design, assembly and evaluation of a dual frequency mechanically scanne... more Abstract We report on the design, assembly and evaluation of a dual frequency mechanically scanned transducer for ultrasound bubble manipulation and real time high frequency imaging applications. A low frequency 2 MHz annulus was designed to fit on ...
Performance and Characterization of New Micromachined High-Frequency Linear Arrays
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, Oct 1, 2006
A new approach for fabricating high frequency (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;a... more A new approach for fabricating high frequency (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 20 MHz) linear array transducers, based on laser micromachining, has been developed. A 30 MHz, 64-element, 74-microm pitch, linear array design is presented. The performance of the device is demonstrated by comparing electrical and acoustic measurements with analytical, equivalent circuit, and finite-element analysis (FEA) simulations. All FEA results for array performance have been generated using one global set of material parameters. Each fabricated array has been integrated onto a flex circuit for ease of handling, and the flex has been integrated onto a custom printed circuit board test card for ease of testing. For a fully assembled array, with an acoustic lens, the center frequency was 28.7 MHz with a one-way -3 dB and -6 dB bandwidth of 59% and 83%, respectively, and a -20 dB pulse width of -99 ns. The per-element peak acoustic power, for a +/- 30 V single cycle pulse, measured at the 10 mm focal length of the lens was 590 kPa with a -6 dB directivity span of about 30 degrees. The worst-case total cross talk of the combined array and flex assembly is for nearest neighboring elements and was measured to have an average level -40 dB across the -6 dB bandwidth of the device. Any significant deviation from simulation can be explained through limitations in apparatus calibration and in device packaging.
Techniques to determine the complex material constants of spherical and cylindrical ring resonators
... Ron Tasker&amp;#x27;, Marc Lukacs&amp;#x27;, Mike Saye?, Stewart Shemt&am... more ... Ron Tasker&amp;#x27;, Marc Lukacs&amp;#x27;, Mike Saye?, Stewart Shemt&amp;#x27; I TASI Technical Software, Kingston, ON, CANADA 2Queen&amp;#x27;s University, Kingston, ON, CANADA &amp;#x27;Royal Military College, Kingston, ON ... http://wwwtasitcchnical.corn/ [IO] TASI Technical Software, 1 Mack St., Unit 4, Kingston, ...
Novel PZT films for ultrasound biomicroscopy
Lead zirconate titanate (PZT) ceramic films of thickness 5-200 μm have been produced on various s... more Lead zirconate titanate (PZT) ceramic films of thickness 5-200 μm have been produced on various substrates using a modified sol gel process. A subset of these films (5-27 μm) open the possibility of fabricating ceramic ultrasound transducers in the frequency range of 80-200 MHz. The technique involves mixing PZT powder conventional PZT sol gel to form a paint which is
Thick and Composite Piezoelectric Coatings for Biomedical and High Temperature Ultrasound
Springer eBooks, 2000
THICK AND COMPOSITE PIEZOELECTRIC COATINGS FOR BIOMEDICAL AND HIGH TEMPERATURE ULTRASOUND M. SAYE... more THICK AND COMPOSITE PIEZOELECTRIC COATINGS FOR BIOMEDICAL AND HIGH TEMPERATURE ULTRASOUND M. SAYER, M. LUKACS, G. PANG, L. ZOU, Y. CHEN Department of Physics, Queen's University, Kingston, Ontario, K7L 3N6 Canada CK JEN Industrial Materials ...
Single element and linear array PZT ultrasound biomicroscopy transducers
PZT coatings have been produced in the thickness range of 5-200 microns using a composite sol gel... more PZT coatings have been produced in the thickness range of 5-200 microns using a composite sol gel process (M. Lukacs et al., 1996). The application of this process in the fabrication of high frequency transducers suitable for ultrasound biomicroscopy (UBM) has been investigated. Curved single element transducers have been produced in a range of 70-165 MHz with -6dB bandwidths as
Single element high frequency (<50 MHz) PZT sol gel composite ultrasound transducers
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2000
A sol gel composite process has been used to produce lead zirconate titanate coatings in the thic... more A sol gel composite process has been used to produce lead zirconate titanate coatings in the thickness range of 3 to 100 microm on aluminum substrates. The complex permittivity (epsilon(33)(S )), elastic stiffness (c(33)(D)), and the piezoelectric constant (h(33)) of the coating and the complex elastic stiffness (c(33)(D)) of the substrate have been determined using impedance measurements and a commercially available software program [Piezoelectric Resonance Analysis Program PRAP 2.0, TASI Technical Software, Kingston, Ontario, Canada]. The complex components of the material parameters account for the losses within the film and the substrate. Sol gel composite films on aluminum have a dielectric constant of 220 with an imaginary component of 1% and an electromechanical coupling coefficient of up to 0.24 with an imaginary component of 3%. These films are applied to the fabrication of a high frequency transducers suitable for ultrasound biomicroscopy (UBM). By combining the sol gel composite material with existing transducer fabrication techniques, single-element focusing transducers have been produced that operate in the frequency range of 70 to 160 MHz. Devices have -6-dB bandwidths up to 52% and minimum insertion losses ranging from -47 to -58 dB. Real-time images of phantom materials and ex vivo biological samples are shown.
Sol-gel PZT thick films for ultrasonic imaging
Ultrasound transducers for B-mode medical imaging are typically operated between 1 and 10 MHz. Re... more Ultrasound transducers for B-mode medical imaging are typically operated between 1 and 10 MHz. Research has been directed towards developing transducers that are sensitive in the 10-100 MHz range because a number of clinical problems require higher resolution than can be achieved at the lower frequencies. Using a modified sol-gel technique developed at Queen&amp;#39;s University, lead zirconate titanate (PZT) thin
Ultra-fine piezoelectric composites for high frequency ultrasonic transducers
This paper presents a new technique called interdigital phase bonding (IPhB) that has been develo... more This paper presents a new technique called interdigital phase bonding (IPhB) that has been developed to make 2-2 PZT composites of ultra-fine pitch for use as transducers and arrays operating at frequencies &amp;gt;30 MHz. By using the IPhB method, a composite structure with a pitch that is less than the dicing saw blade thickness can be created. The flexibility of
Laser micromachined high frequency ultrasonic arrays
Piezoelectric ceramics have been patterned by means of laser micromachining to create ultrasonic ... more Piezoelectric ceramics have been patterned by means of laser micromachining to create ultrasonic arrays resonating in the frequency range of 35-45 MHz. The Lumonics PM-844 excimer laser with a KrF gas mixture (248 nm) has been used to micromachine trenches with a width to depth aspect ratio of up to 1:5. By using a projection etch approach, the large aperture
Process Optimization for Piezoelectric Films and Coatings
MRS Proceedings, 1997
ABSTRACTThe dielectric and piezoelectric response of sol gel based films and composite coatings i... more ABSTRACTThe dielectric and piezoelectric response of sol gel based films and composite coatings is affected by the choice of process, gel composition, thermal cycle, processing atmosphere and poling conditions. Important general factors for thin films are the crystallization kinetics and the effects of residual carbon, while a new dielectric technique allows poling methods to be evaluated.
High frequency piezo-composite transducer with hexagonal pillars
Abstract Developing a high-frequency piezo-composite material is a challenge due to the extremely... more Abstract Developing a high-frequency piezo-composite material is a challenge due to the extremely small pillar dimensions. The high frequency composites made by conventional dicing saw techniques will most likely have a low ceramic volume fraction and a large ...
Performance and characterization of high frequency linear arrays
Simulations of the array characteristics based on finite element analysis performed with PZFlex s... more Simulations of the array characteristics based on finite element analysis performed with PZFlex show good agreement with experimental results. Synthesized images based on the measured performance of the array elements for a given fabricated transducer will also be ...
MRS Proceedings, 1997
The analytical solution of the wave equation for a piezoelectric layer supported by a substrate i... more The analytical solution of the wave equation for a piezoelectric layer supported by a substrate is presented. Using the appropriate boundary conditions, the impedance for a piezoelectric layer driven in the thickness axis is derived and expressed in terms of the mechanical, electrical and piezoelectrical properties of the two materials. This solution allows for the extension of the free resonator IEEE impedance techniques and provides a nondestructive method for determining the material parameters of a piezoelectric film with mechanical support. The validity and universality of the model is demonstrated by measurements on composite sol gel PZT coatings within the thickness range of 15-70lm on aluminum substrates of varying thickness, and by simulating the mass loading of a quartz thickness resonator.
Ultrasound in Medicine and Biology, Oct 1, 2009
Most institutions now have a suite of imaging tools to follow mouse models of human disease. Micr... more Most institutions now have a suite of imaging tools to follow mouse models of human disease. Microultrasound is one of these tools and is second after whole-mouse fluorescence or bioluminescent imaging, in terms of installed systems. We report in this paper the first commercially available array transducer-based ultrasound imaging system that enables micro-ultrasound imaging at center frequencies between 15 and 50 MHz. At the heart of the new scanner is a laser-machined high-frequency 256 element, linear transducer array capable of forming dynamic diffraction limited beams. The power of the linear array approach is embodied in the uniform high resolution maintained over the full field of view. This leads to greatly expanded scope for real-time functional imaging that is demonstrated in this paper. The unprecedented images made with the new imaging system will enable many new applications not previously possible. These include real-time visualization of flow in the mouse placenta, visualization of flow development in the embryo, studies of embryonic to adult cardiac development/disease, and studies of real-time blood flow in mouse models of tumour angiogenesis.
Ultra-Fine Piezoelectric Composites For High Frequency
This paper presents a new technique called interdigital phase bonding (IPhB) that has been develo... more This paper presents a new technique called interdigital phase bonding (IPhB) that has been developed to make 2-2 PZT composites of ultra-fine pitch for use as transducers and arrays operating at frequencies &amp;gt;30 MHz. By using the IPhB method, a composite structure with a pitch that is less than the dicing saw blade thickness can be created. The flexibility of
Proceedings of SPIE, Jul 15, 1999
ABSTRACT
Design and Fabrication of Ultrafine Piezoelectric Composites
Ultrasonic Imaging, 2005
Making fine scale (< 20 microm) piezoelectric composites for high frequency (> 50 M... more Making fine scale (< 20 microm) piezoelectric composites for high frequency (> 50 MHz) ultrasound transducers remains challenging. Interdigital phase bonding (IPhB), described in this paper, presents a new technique developed to make piezoelectric composites at the ultrafine scale using a conventional dicing saw. Using the IPhB technique, a composite structure with a pitch that is less than the dicing saw blade thickness can be created. The approach is flexible enough to make composites of different combination of pitch and volume ratio. Using a conventional dicing saw with a 50 microm thick blade, composite with a 25 microm pitch and a volume ratio of 61 percent are fabricated. Such a composite is suitable for fabrication of ultrasonic transducers and arrays with central frequencies of up to 85 MHz. Single element transducers working at central frequencies of 50-60 MHz were made of these composites as a mean to characterize the acoustic performance. Measurement results of the transducers show that the longitudinal electromechanical coupling coefficient is greater than 0.6 and that there are no noticeable lateral resonances in the frequency range of 55-150 MHz. Design criteria for fine scale elements are also discussed based on theoretical results from finite element analysis (FEA).
Proceedings of SPIE, May 1, 1998
Ceramic ultrasonic transducers with a frequency response <50MHz using lead zirconate titanate ... more Ceramic ultrasonic transducers with a frequency response <50MHz using lead zirconate titanate (PZT) layers in the 5-4Otm range have been difficult to achieve by bulk or thin film techniques. Advances in the production of small sized PZT ceramic powder allow the development ofthinner ceramic layers for this application. Sol gel composite thin film technology also provides a new technique for producing ceramic coatings of a thickness that successfully bridges the gap between traditional thin film and bulk techniques. So! gel composite PZT layers of 5-7Om have been coated on substrates (aluminum, platinized silicon, stainless steel, .. .) that can withstand the thermal processing of the ceramic. The thickness mode response of a thin piezoelectric layer supported by a thick substrate has been modeled from first principles using complex material constants. The LevenbergMarquart non linear regression technique has been used to extract the thickness mode elastic stiffness, dielectric constant and piezoelectric constant of the PZT, and the elastic stiffness of the substrate from the layered structure. This non-destructive technique allows for a reliable assessment of the quality of a coating prior to the fabrication of a transducer. The elastic stiffness of the substrate is not lossy enough for the required broadband response of an imaging transducer. However, aluminum can be preferentially etched, releasing the ceramic coating. Therefore it is possible to transfer the PZT film to a more suitable backing material. A processing sequence for single element PZT transducers in the frequency range of 50-200MHz has been developed. Characterization of transducers has been performed using pulse-echo techniques and by creating real time B-scan images of agar phantoms and biological tissue. Methods for patterning the PZT composite coatings are being developed with the intent to fabricate a linear array in the 40-60 MHz frequency range. Due to the very fine patterning and high concentration of cuts required for a high aspect ratio linear array, the limits of conventional etching techniques are surpassed. Laser micromachining using a frequency doubled Nd:YAG and a KrF excimer laser have the ability to pattern the array structure. In both cases, laser cuts <1Om wide have been achieved.
Thickness mode material constants of a supported piezoelectric film
Journal of Applied Physics, Mar 1, 1999
New thick film ceramic processing techniques and microelectromechanical systems require material ... more New thick film ceramic processing techniques and microelectromechanical systems require material characterization of a piezoelectric film supported by a substrate. An analytical solution of the one-dimensional wave equation for multiple layered systems driven in the thickness mode is presented. The impedance across the piezoelectric layer is derived and expressed in terms of the material properties of the two materials. This includes the open-circuit elastic stiffness c33D, the clamped permittivity ε33S and the h33 piezoelectric constant of the piezoelectric layer and the elastic stiffness csD of the substrate. The properties are expressed as complex variables in order to account for the losses within the materials. The material parameters of the solution are extracted from experimental results using a modified Levenberg–Marquardt technique. The capabilities of this nondestructive technique are demonstrated using experimental and simulated impedance spectra of lead zirconium titanate sol gel composite coatings within the thickness range of 15–70 μm on aluminum and on platinum electroded silicon substrates and by simulating the mass loading of a quartz thickness resonator. The analytical solution allows for the extension of the Institute of Electrical and Electronics Engineers free resonator impedance technique to supported films and provides a method for determining the material parameters of a piezoelectric coating.
Hybrid dual frequency transducer and Scanhead for micro-ultrasound imaging
Abstract We report on the design, assembly and evaluation of a dual frequency mechanically scanne... more Abstract We report on the design, assembly and evaluation of a dual frequency mechanically scanned transducer for ultrasound bubble manipulation and real time high frequency imaging applications. A low frequency 2 MHz annulus was designed to fit on ...
Performance and Characterization of New Micromachined High-Frequency Linear Arrays
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, Oct 1, 2006
A new approach for fabricating high frequency (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;a... more A new approach for fabricating high frequency (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 20 MHz) linear array transducers, based on laser micromachining, has been developed. A 30 MHz, 64-element, 74-microm pitch, linear array design is presented. The performance of the device is demonstrated by comparing electrical and acoustic measurements with analytical, equivalent circuit, and finite-element analysis (FEA) simulations. All FEA results for array performance have been generated using one global set of material parameters. Each fabricated array has been integrated onto a flex circuit for ease of handling, and the flex has been integrated onto a custom printed circuit board test card for ease of testing. For a fully assembled array, with an acoustic lens, the center frequency was 28.7 MHz with a one-way -3 dB and -6 dB bandwidth of 59% and 83%, respectively, and a -20 dB pulse width of -99 ns. The per-element peak acoustic power, for a +/- 30 V single cycle pulse, measured at the 10 mm focal length of the lens was 590 kPa with a -6 dB directivity span of about 30 degrees. The worst-case total cross talk of the combined array and flex assembly is for nearest neighboring elements and was measured to have an average level -40 dB across the -6 dB bandwidth of the device. Any significant deviation from simulation can be explained through limitations in apparatus calibration and in device packaging.
Techniques to determine the complex material constants of spherical and cylindrical ring resonators
... Ron Tasker&amp;#x27;, Marc Lukacs&amp;#x27;, Mike Saye?, Stewart Shemt&am... more ... Ron Tasker&amp;#x27;, Marc Lukacs&amp;#x27;, Mike Saye?, Stewart Shemt&amp;#x27; I TASI Technical Software, Kingston, ON, CANADA 2Queen&amp;#x27;s University, Kingston, ON, CANADA &amp;#x27;Royal Military College, Kingston, ON ... http://wwwtasitcchnical.corn/ [IO] TASI Technical Software, 1 Mack St., Unit 4, Kingston, ...
Novel PZT films for ultrasound biomicroscopy
Lead zirconate titanate (PZT) ceramic films of thickness 5-200 μm have been produced on various s... more Lead zirconate titanate (PZT) ceramic films of thickness 5-200 μm have been produced on various substrates using a modified sol gel process. A subset of these films (5-27 μm) open the possibility of fabricating ceramic ultrasound transducers in the frequency range of 80-200 MHz. The technique involves mixing PZT powder conventional PZT sol gel to form a paint which is
Thick and Composite Piezoelectric Coatings for Biomedical and High Temperature Ultrasound
Springer eBooks, 2000
THICK AND COMPOSITE PIEZOELECTRIC COATINGS FOR BIOMEDICAL AND HIGH TEMPERATURE ULTRASOUND M. SAYE... more THICK AND COMPOSITE PIEZOELECTRIC COATINGS FOR BIOMEDICAL AND HIGH TEMPERATURE ULTRASOUND M. SAYER, M. LUKACS, G. PANG, L. ZOU, Y. CHEN Department of Physics, Queen's University, Kingston, Ontario, K7L 3N6 Canada CK JEN Industrial Materials ...
Single element and linear array PZT ultrasound biomicroscopy transducers
PZT coatings have been produced in the thickness range of 5-200 microns using a composite sol gel... more PZT coatings have been produced in the thickness range of 5-200 microns using a composite sol gel process (M. Lukacs et al., 1996). The application of this process in the fabrication of high frequency transducers suitable for ultrasound biomicroscopy (UBM) has been investigated. Curved single element transducers have been produced in a range of 70-165 MHz with -6dB bandwidths as
Single element high frequency (<50 MHz) PZT sol gel composite ultrasound transducers
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2000
A sol gel composite process has been used to produce lead zirconate titanate coatings in the thic... more A sol gel composite process has been used to produce lead zirconate titanate coatings in the thickness range of 3 to 100 microm on aluminum substrates. The complex permittivity (epsilon(33)(S )), elastic stiffness (c(33)(D)), and the piezoelectric constant (h(33)) of the coating and the complex elastic stiffness (c(33)(D)) of the substrate have been determined using impedance measurements and a commercially available software program [Piezoelectric Resonance Analysis Program PRAP 2.0, TASI Technical Software, Kingston, Ontario, Canada]. The complex components of the material parameters account for the losses within the film and the substrate. Sol gel composite films on aluminum have a dielectric constant of 220 with an imaginary component of 1% and an electromechanical coupling coefficient of up to 0.24 with an imaginary component of 3%. These films are applied to the fabrication of a high frequency transducers suitable for ultrasound biomicroscopy (UBM). By combining the sol gel composite material with existing transducer fabrication techniques, single-element focusing transducers have been produced that operate in the frequency range of 70 to 160 MHz. Devices have -6-dB bandwidths up to 52% and minimum insertion losses ranging from -47 to -58 dB. Real-time images of phantom materials and ex vivo biological samples are shown.
Sol-gel PZT thick films for ultrasonic imaging
Ultrasound transducers for B-mode medical imaging are typically operated between 1 and 10 MHz. Re... more Ultrasound transducers for B-mode medical imaging are typically operated between 1 and 10 MHz. Research has been directed towards developing transducers that are sensitive in the 10-100 MHz range because a number of clinical problems require higher resolution than can be achieved at the lower frequencies. Using a modified sol-gel technique developed at Queen&amp;#39;s University, lead zirconate titanate (PZT) thin
Ultra-fine piezoelectric composites for high frequency ultrasonic transducers
This paper presents a new technique called interdigital phase bonding (IPhB) that has been develo... more This paper presents a new technique called interdigital phase bonding (IPhB) that has been developed to make 2-2 PZT composites of ultra-fine pitch for use as transducers and arrays operating at frequencies &amp;gt;30 MHz. By using the IPhB method, a composite structure with a pitch that is less than the dicing saw blade thickness can be created. The flexibility of
Laser micromachined high frequency ultrasonic arrays
Piezoelectric ceramics have been patterned by means of laser micromachining to create ultrasonic ... more Piezoelectric ceramics have been patterned by means of laser micromachining to create ultrasonic arrays resonating in the frequency range of 35-45 MHz. The Lumonics PM-844 excimer laser with a KrF gas mixture (248 nm) has been used to micromachine trenches with a width to depth aspect ratio of up to 1:5. By using a projection etch approach, the large aperture
Process Optimization for Piezoelectric Films and Coatings
MRS Proceedings, 1997
ABSTRACTThe dielectric and piezoelectric response of sol gel based films and composite coatings i... more ABSTRACTThe dielectric and piezoelectric response of sol gel based films and composite coatings is affected by the choice of process, gel composition, thermal cycle, processing atmosphere and poling conditions. Important general factors for thin films are the crystallization kinetics and the effects of residual carbon, while a new dielectric technique allows poling methods to be evaluated.
High frequency piezo-composite transducer with hexagonal pillars
Abstract Developing a high-frequency piezo-composite material is a challenge due to the extremely... more Abstract Developing a high-frequency piezo-composite material is a challenge due to the extremely small pillar dimensions. The high frequency composites made by conventional dicing saw techniques will most likely have a low ceramic volume fraction and a large ...
Performance and characterization of high frequency linear arrays
Simulations of the array characteristics based on finite element analysis performed with PZFlex s... more Simulations of the array characteristics based on finite element analysis performed with PZFlex show good agreement with experimental results. Synthesized images based on the measured performance of the array elements for a given fabricated transducer will also be ...