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Design, Modeling and Fabrication of a Novel Class V Flextensional Transducer:
The Sea-Shell
Article in IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control · November 2022
DOI: 10.1109/TUFFC.2022.3224076
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IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL, VOL. 70, NO. 1, JANUARY 2023
Design, Modeling and Fabrication of a Novel
Class V Flextensional Transducer:
The Sea-Shell
Mustafa Yunus Kaya
and Sedat Alkoy , Member, IEEE
Abstract —In this study, a novel class V flextensional
transducer (FT) was developed by assembling
symmetrically convex ceramic and metal caps to form
a seashell-like structure. The transducer was designed
and analyzed using ATILA finite element analysis (FEA)
software. The diameter, thickness, and radius of curvature
of the ceramic and metal shells have been investigated as
design parameters. The transducer was found to display
four distinct flextensional modes in addition to the main
radial resonance mode between 1 and 200 kHz frequency
range. Prototypical devices were fabricated from four
different commercial lead zirconate titanate (PZT) compositions and underwater performances were compared.
Transmitting voltage responses (TVRs) were observed to range between 120 and 135 dB (ref 1 µPa/V) at frequencies
above 50 kHz.
Index Terms — Class V, finite element analysis (FEA), flextensional transducer (FT), piezoceramic.
I. I NTRODUCTION
N ELECTROACOUSTIC transducer converts acoustic
energy into electrical energy or vice versa, converting
electrical energy into acoustic signals [1], [2]. Electroacoustic
transducers are important for underwater applications, where
they are used as transmitters, receivers, or operating in both
ways. However, a single transducer cannot operate efficiently
in the entire 1 kHz–1 MHz frequency range and thus, various
transducer designs were developed and optimized for specific
frequency ranges and impedance requirements. Among various
transducer designs, flextensional transducers (FTs) were developed for lower frequency requirements where high volumetric
velocities are required. FTs consist of an active driving element
such as a piezoelectric, an electrostrictive, or a magnetostrictive material that is coupled to a flexing metal shell [1], [2],
[3], [4], [5], [6], [7]. Fabrication and testing of the first known
A
Manuscript received 7 October 2022; accepted 17 November 2022.
Date of publication 23 November 2022; date of current version
12 January 2023. This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under Project 116M216.
(Corresponding author: Mustafa Yunus Kaya.)
Mustafa Yunus Kaya was with the Department of Materials Science and Engineering, Gebze Technical University, 41400 Kocaeli,
Turkey. He is now with the Department of Metallurgical and Materials
Engineering, Bursa Technical University, 16310 Bursa, Turkey (e-mail:
mustafayunus.kaya@btu.edu.tr).
Sedat Alkoy is with the Department of Materials Science and
Engineering, Gebze Technical University, 41400 Kocaeli, Turkey (e-mail:
sedal@gtu.edu.tr).
This article has supplementary downloadable material available at
https://doi.org/10.1109/TUFFC.2022.3224076, provided by the authors.
Digital Object Identifier 10.1109/TUFFC.2022.3224076
.
.
.
.
.
flextensional, i.e., flexural-extensional transducer based on the
design of Hayes was made in 1929 [6], [7], [8]. Hayes has
also received an FT patent based on a magnetostrictive rod as
the main drive element, intended to be used mainly in the air
at audible frequencies [7], [8]. Later, in the 1950s and 1960s,
Toulis [9], Abbott [10], and Merchant [11] extended the use
of FTs into the water domain as transmitters for high-voltage
and low-frequency applications using piezoelectric ceramic
material as the main drive element instead of a magnetostrictive rod. FTs are divided into seven sub-classes and their
sizes can range from centimeters to meters scale and they
can weigh from several grams up to hundreds of kilograms
[1], [4]. Several of these designs have been miniaturized for
higher frequency applications, where fabrication complexity
and production costs have also been decreased.
Miniaturization has successfully been demonstrated in
Class V FTs which consist of a thin ceramic disk or ring
combined with metal shells on both sides. “Moonie” transducer, which was developed in the 1990s is a miniaturized
version of Class V and it was named “Moonie” due to the
crescent-shaped cavity on the inner side of the metal cap
[13], [14]. On the other hand, “Cymbal” is the second generation of the Moonie type Class V transducers, which consisted
of thinner metal caps shaped like the musical instrument of
the same name, which emerged in the mid-1990s [13]. In both
of these designs, the interior surfaces of the metal caps have
cavities, and these cavities amplify small radial movements
of the ceramics to larger axial displacements normal to metal
surfaces [13]. As a result of this, an amplification mechanism
1525-8955 © 2022 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.
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.
.
KAYA AND ALKOY: DESIGN, MODELING AND FABRICATION OF A NOVEL CLASS V FT: THE SEA-SHELL
65
Highlights
• A novel class V flextensional transducer consisting of symmetrical metal and ceramic caps with convex geometry
with a Sea-Shell form was designed and optimized by finite element analysis (FEA).
•
Four flextensional modes and one radial vibration mode were identified. Resonance frequencies could be shifted by
varying the dimensions. Prototypes were fabricated and FEA were confirmed with measurements.
•
The Sea-Shell transducer emerges as a promising candidate allowing a thin-profile array design for shallow-water
underwater applications in the 50–100 kHz range.
with high acoustic output can be obtained. Although these
metal-ceramic composite structures provide rather high strains
and high acoustic sensitivity through the flexural-extensional
mechanism, there are alternative approaches to obtain high
strain or high acoustic output from a monolithic ceramic
itself. The Rainbow is one such approach, where fabricating a
stress-biased, monolithic ceramic through chemically reducing
a lead-based piezoelectric ceramic wafer provides a builtin amplification mechanism due to the dome shape of the
Rainbow transducers [14].
In this work, a miniaturized novel Class V FT was developed, combining the metal shell of the Class V flextensional design with that of a dome-shaped ceramic, thereby
accessing the amplification mechanism and advantages of
both approaches. The transducer is monikered “Sea-Shell”
due to the use of symmetrical convex-shaped metal and
ceramic caps. This study consists of two main stages, the
development of the transducer and the experimental validation of the design. In the development part, finite element
analysis (FEA) was used to analyze the vibration modes
and optimize the design and predict the performance of the
device. The commercial ATILA FEA code was used in this
stage. ATILA was specifically developed to analyze active
structures under electrical and magnetic drive conditions and
computes their in-air and underwater response [15], [16],
[17], [18] and in this study, it was used to analyze the
main vibration modes of the Sea-Shell as well as to obtain
the device properties depending on parameters such as the
type and the thickness of the metal caps and ceramic shells.
In the second stage, the Sea-Shell transducers were fabricated
using a brass metal cap with identical ceramic caps based
on the FEA results. In-air and underwater measurements
were done, and the results were compared with that of the
FEA study.
II. M ATERIALS AND M ETHODS
In the first stage of this work, ATILA FEA (6.0.0.6) software
was used to design and analyze the novel Class V FT, the SeaShell. Because of its axisymmetric shape, the device models
were formed in 2-D using the GID 10.9 preprocessor interface,
and the analysis and optimization process was conducted
for various parameters (i.e., ceramic shell and metal cap
thickness, device radius, etc.). Harmonic analysis was done
both in-air and underwater as a medium in a frequency
range from 1 to 200 kHz. Frequency-dependent admittance
spectra were compared for each design parameter to obtain
the simulated performance of the device. “Cymbal” transducer
Fig. 1. Schematic representation of the Sea-Shell device. (a) Twodimensional axisymmetric sketch. (b) Three-dimensional cross section
where green and blue colors denote metal and ceramic parts,
respectively.
with similar dimensions was used as a benchmark reference.
A 2-D axisymmetric drawing of the Sea-Shell was given in
Fig. 1(a) with the definitions of the main parameters. Also,
the figures showing the boundary conditions of 2-D models
were given in supplementary files as SP Fig. 1 and SP Fig. 2.
Cross section of the transducer in 3-D was given in Fig. 1(b)
for better visualization of the device.
Prototypes of the Sea-Shell were also fabricated to validate
the results of the FEA and to realize the design. Initial FEA
studies were carried out using reference dimensions given in
Table I. However, due to the variation of shrinkage of the
ceramic bodies during the actual processing conditions and the
unavailability of commercial brass with 0.25 mm thickness,
new FEA models were created, and analyses were conducted
according to the actual prototype dimensions. Dimensions of
the prototypical device were 13.5 mm diameter, 1 mm ceramic
thickness, 0.3 mm metal cap thickness, and 1.5 mm inner
cavity depth between the metal cap and the ceramic shell with
boundary conditions. Brass was used as the metal cap material
and the shaping of the metal disk into a dome shape was done
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IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL, VOL. 70, NO. 1, JANUARY 2023
TABLE I
R EFERENCE M ODEL D IMENSIONS
using a press mold under uniaxial pressure. Ceramic shells
were fabricated using commercially available lead zirconate
titanate (PZT) powders (Sunnytec, Taipei, Taiwan). Ceramic
shells were shaped using two different methods. Slip casting
into plaster of Paris molds was done according to previously
reported studies in the literature [18], [19]. As a second
shaping method, uniaxial pressing between steel dies with
a shell-shaped cavity was used. Sintering of ceramic shells
was done at 1260 ◦ C with a dwelling time of 4 h in a
double crucible configuration under a PbO-rich atmosphere.
Silver paste (ESL-9910C) electrode was applied to the parallel surfaces of the ceramic shells and fired at 600 ◦ C for
30 min. The ceramic shells were poled under an electric
field of 20 kV/cm for 10 min at 120 ◦ C in silicon oil using
a high voltage dc power supply (Trek Inc., Lockport, NY,
USA). The Sea-Shell transducers were fabricated by applying conductive adhesive polymer (ESL-Europe Conductive
Polymer) to the rim of the ceramic shells and metal caps,
and once the curing of the adhesive element was completed,
thin copper cables were soldered to the outer surface of the
rims. The Sea-Shell transducers were coated with polyurethane
(Biresin U1305, Sika) to electrically insulate the transducer
and form an acoustic coupling medium. In addition, the
acoustic impedance of materials used in the model and prototypes were given in a supplementary file as SP Table I. In-air
and underwater, the characterization of devices was done using
an impedance analyzer (Keysight E4990A). The underwater
characterization process was done as previously reported in
the literature and details were provided in the supplemental
document [2], [18].
III. R ESULTS AND D ISCUSSIONS
A. Finite Elements Modeling and Analysis of the
Sea-Shell Transducer Design
The initial design of the Sea-Shell transducer was analyzed
through the FEA method to understand the vibration modes
and frequency response of the device while at the same
time fine-tuning the device design. In-air admittance-frequency
spectrum of the Sea-Shell obtained from the FEA study was
given in Fig. 2 in comparison with “Cymbal.” In the FEA
study, identical reference dimensions, as given in Table I,
were used for Cymbal and Sea-Shell transducers for a fair
comparison. Apart from the main radial mode at 162 kHz, four
different vibration modes were also identified in the frequency
range from 1 to 200 kHz for the Sea-Shell design, compared
to a single flextensional vibration mode of the Cymbal design.
Fig. 2. Two-dimensional sketch of (a) Cymbal, (b) Sea-Shell transducers,
and (c) comparison of admittance spectra for devices with reference
dimensions.
Fig. 3. (a)–(f) Vibration modes of Sea-Shell transducers at various
resonance frequencies.
Resonance frequency values of these modes for the reference
Sea-Shell design were 22, 46, 73.5, and 131 kHz. In Fig. 3
vibration modes were given in order to observe the displacement mechanism of the Sea-Shell transducer at different
frequencies. Flextensional movements were obtained at the
first frequency. However, the second resonance mode is related
to the ceramic bending mode and von Misses stresses analysis
was given in SP Fig. 3 to show stress distribution under
reference potential application. The third and fourth vibration
modes were identified as higher-order flextensional modes.
Since the first vibration mode was found to be weaker than the
second resonance, further FEA analysis stages were conducted
with a focus to superimpose resonance modes by adjusting
parameters such as ceramic thickness, device diameter, cavity
depth, etc.
KAYA AND ALKOY: DESIGN, MODELING AND FABRICATION OF A NOVEL CLASS V FT: THE SEA-SHELL
67
Fig. 4. Variation of in-air resonance frequencies of the flextensional vibration modes with respect to (a) ceramic thickness, (b) metal thickness,
(c) cavity depth between shells, and (d) device diameter, where all the other dimensions were held constant according to Table I.
The effect of various design parameters on resonance frequencies of the Sea-Shell transducer geometry, were given
in Fig. 4. Increasing ceramic thickness [see Fig. 4(a)], metal
thickness [see Fig. 4(b)], and the cavity depth between inner
domes of ceramic and metal shell [see Fig. 4(c)] resulted in
a general shift of the primary resonance modes of transducer
toward higher frequencies while increasing the device diameter [see Fig. 4(d)] shifts all the resonance modes to lower
frequencies. The aim of the study is to bring the frequencies
of the relevant resonance modes closer rather than overlapping
them at a single peak point. When the resonance frequencies
of different modes come closer to create two transmitting
voltage response (TVR) peaks and a shallow plateau region
in between, then the effective bandwidth of the transducer
is expected to increase. Thus, the approaching of different
resonance modes can be noticed depending on the variation of
the aforementioned design parameters individually in Fig. 4.
This is due to the fact that frequencies of different vibration
modes were affected with varying degrees from device parameters. This approach of different vibration modes toward
similar frequency ranges would allow us to design underwater
transducers with wider bandwidths. As an example, decreasing
the ceramic thickness toward 0.75 mm would lead to a general
approach of all three modes toward a frequency range of
10–40 kHz. These results as a whole point to the flexibility
of this transducer design in engineering the the frequency
range of operations, the bandwidth, and the corresponding
performance. Although varying a single device parameter to
obtain an approaching of the resonance frequencies of various
vibration modes was demonstrated in Fig. 4, variation of more
than a single parameter may be required in certain situations.
The hydrostatic pressures that the Sea-Shell transducer has
to handle will depend on the depth that the device will
operate in underwater transducer applications. For example,
operation under higher hydrostatic pressures would require
increasing the thickness of the ceramic shell and/or metal
caps, while increasing the depth of the cavity between them,
or switching to a stiffer metal cap material while increasing
the cavity depth. Thus, simultaneous variation of more than
a single device parameter was investigated to evaluate their
effectiveness and their trend in modifying the operational
frequencies. The results of these analyses were given in Fig. 5
for the first resonance mode. In the case of simultaneously
increasing the ceramic thickness and the cavity depth between
inner domes, the first resonance mode was found to vary
linearly with respect to the constituent parameters, and a shift
to slightly higher frequencies was observed at higher cavity
depths, as seen in Fig. 5(a). Whereas, when the ceramic and
metal shell thickness values were increased simultaneously, [as
shown in Fig. 5(b)], a drastic increase was observed in the first
resonance frequency of the Sea-Shell transducer. However,
when these results were evaluated in light of the trends shown
in Fig. 5(a), the frequency shift was determined to be mainly
a function of metal thickness in this case. In other words,
metal shell thickness is the main determining factor of the
frequency shift observed in the first flextensional vibration
68
IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL, VOL. 70, NO. 1, JANUARY 2023
Fig. 5. Variation of in-air resonance frequency of the first flextensional vibration mode with respect to simultaneous changes in (a) ceramic shell
thickness and cavity depth, (b) thickness of the ceramic shell and metal caps, (c) metal cap thickness and cavity depth, and (d) metal cap material
and cavity depth, where all the other dimensions were held constant according to Table I.
Fig. 6. Variation of underwater TVR of the Sea-Shell transducers with respect to (a) ceramic thickness, (b) metal thickness, (c) cavity depth between
the shells, and (d) device diameter.
mode due to the lower elastic modulus of the metal caps
compared to the ceramic shell, as was demonstrated in the
literature in the case of cymbal transducers [13], [20], [22].
With this result in mind, metal caps were the focus of further
KAYA AND ALKOY: DESIGN, MODELING AND FABRICATION OF A NOVEL CLASS V FT: THE SEA-SHELL
analysis. In Fig. 5(c), the combined effect of cavity depth
between the inner domes of the shells and the metal thickness
on the frequency of the first flextensional resonance mode
was given. A general increase in the resonance frequency
was observed with increasing metal cap thickness as well
as the cavity depth. As the depth of the Sea-Shell increases,
the domes of the device become more sphere-like, and thus,
the first resonance frequency gradually approaches that of the
main radial resonance mode which started just after at a depth
of 1.5 mm. Thus, especially increased spheroidization on the
dome at 2 mm depth is the cause of the abrupt slope increase in
linearity that was observed in Fig. 5(c). Finally, the variation
of the frequency of the first flextensional resonance mode
with the type of metal cap material was investigated where
brass, copper, titanium, and steel were considered. Results
were presented in Fig. 5(d) where a nice and expected scaling
up of materials was observed in the resonance frequency which
was directly proportional to the elastic modulus and inversely
proportional to the density of the cap material. The cap
material is also important from two additional perspectives,
namely, the elastic modulus of the material affects the depth
handling capability of the device, and the density of the cap
material affects the acoustic impedance matching of the device
with that of water in underwater applications. Selection should
therefore be done accordingly. The density and the elastic
modulus of the metal cap materials used in our analysis were
given in supplementary SP Table II.
Underwater characteristics of the Sea-Shell transducer were
also analyzed by varying a single design parameter, and results
were given in Fig. 6. TVR characteristics were found to
mirror the in-air characteristics and the approaching of the
resonance modes can clearly be seen for each parameter.
The approaching of TVR peaks of two or more resonance
modes is expected to increase the −3 dB bandwidth of
the transducer. The final step of the FEA of the Sea-Shell
transducer was to investigate the acoustic directivity of the
transducer.
The results were presented in Fig. 7 showing the directivity
beam patterns of the Sea-Shell transducer. The acoustic axis
in this figure is along the horizontal axis of symmetry. The
ceramic shell is located on the left side while the metal cap
is facing toward the right side. The transducer was found to
behave as an omnidirectional point source at the first flextensional mode, while a bipolar directivity beam pattern, having
the symmetry of a peanut shape with two lobes was observed
for the second flextensional mode. The third flextensional
mode displayed a rather directive acoustic response with the
metal cap side displaying an 11 dB higher response compared
to the ceramic shell side. The −3 dB beamwidth was found
to be 120◦ .
B. Fabrication and Characterization of the Sea-Shell
Transducer
The Sea-Shell transducer after assembly was shown in
Fig. 8. Brass with a thickness of 0.3 mm was used as the
metal cap material and various commercial PZT compositions, namely, electrically soft compositions corresponding
to PZT-5A and PZT-5H, and electrically hard compositions
69
Fig. 7. Directivity beam patterns of the Sea-Shell transducers obtained
using ATILA FEA software.
Fig. 8.
Sea-Shell transducer after assembly. (a) Metal cap side.
(b) Ceramic shell side. (c) Potted in polyurethane.
corresponding to PZT-4 and PZT-8 were used as the ceramic
shell material with a thickness of 1 mm. The cavity depth was
1.5 mm, and the diameter of the assembled transducer was
13.5 mm.
The admittance-frequency spectra measured from the device
assembled from soft piezoceramic composition was given in
Fig. 9(a), in comparison with the FEA results conducted for
the soft PZT5A composition. Fig. 9(b) shows a narrow frequency range of the same plot to provide a better comparison
of the flextensional modes. In the comparison of FEA versus
Exp. results given in Fig. 9, the exact dimensions of the prototype device were used in the FEA calculations. The dimensions
of the prototypes were different from the reference dimen-
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IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL, VOL. 70, NO. 1, JANUARY 2023
Fig. 9. In air admittance-frequency comparison of FEA model and
prototype for the Sea-Shell transducers. (a) Full spectrum comparison including main radial mode from 1 kHz to 225 kHz frequencies.
(b) Detailed comparison for flextensional-modes from 1 kHz to 100 kHz
frequencies.
sions given in Table I as explained in Section II. When the
admittance values are taken into consideration, the admittance
magnitude of the PZT-5H composition surpassed other PZT
compositions due to the higher dielectric constant and piezoelectric charge coefficient of PZT-5H. It was also deduced
from the resonance spectra that the alignment symmetry of the
shells affects the sharpness and singularity of the resonance
modes. Additionally, the thickness of the adhesive material
and its adhesion force was found to dampen the sharpness
of resonance modes. The second and fourth vibration modes
were clearly visible in all cases with PZT-5A displaying all
of the resonance modes. Following the in-air characterization,
transducers were coated with polyurethane (Biresin U1305,
Sika) to electrically isolate them from the surroundings and
to provide an acoustic coupling with water. Then, in-water
admittance measurements were conducted using an impedance
analyzer (Keysight E4990A). The results for these measurements are given for each composition in Fig. 10(a). Due to the
hydrostatic pressure and mass loading of water, as well as the
polyurethane coating, the resonance peaks were highly damped
and flattened. The first resonance mode was still observable
below 30 kHz and the second resonance mode was detected
between 60 and 70 kHz frequency range for all devices. The
Fig. 10. In water measurement results of commercial PZT compositions.
(a) Admittance-frequency spectra. (b) Calculated TVR curves.
TVR of the transducer in dB ref 1 µPa/V was calculated from
the in-water admittance measurements [2], [18]. Calculated
TVR curves for various PZT compositions were given in
Fig. 10(b). TVR values for primary resonance mode, which are
below 120 dB were deemed sufficient for underwater acoustics
applications, as was demonstrated in the case of cymbal
transducers [13], [20], [21], [22]. In the case of PZT-5H,
the TVR values were above 115 dB for frequencies above
30 kHz and reached values higher than 120 dB above 50 kHz
frequency values. Also, a comparison of TVR calculated from
in-water admittance measurements and computed by FEA was
given in a supplementary file as SP Fig. 4. Apart from the first
resonance mode, devices with PZT-5H and PZT-5A ceramic
shells seem to be more efficient in terms of application. TVR
curves are one of the benchmarking tools that can be used
to predict device performance. However, using the source
level (SL) is a better comparison tool, especially in the case of
different transducer designs or conditions. As such, although
TVR results indicated that soft PZT-5H and PZT-5A clearly
outperformed others, the dielectric and hysteresis losses that
are associated with soft piezoelectrics prevent their actual use
as projector materials for underwater applications. Due to the
relatively lower losses associated with PZT-4, it is more prone
to be driven with higher voltages and thus Sea-Shell transducer
based on PZT-4 is expected to demonstrate higher SLs.
KAYA AND ALKOY: DESIGN, MODELING AND FABRICATION OF A NOVEL CLASS V FT: THE SEA-SHELL
IV. C ONCLUSION
This work demonstrated the design, fabrication, and characterization stages of a novel class V FT, named after Sea-Shell
due to the resemblance of the design, consisting of convex
ceramic and metal shells. The design was conducted in two
main steps. At first, conceptual research was carried out using
ATILA FEA software and several parameters were tested using
the FEA method to identify resonance frequencies and device
performance of Sea-Shell design. Four flextensional vibration
modes were identified, in addition to the radial vibration of the
shells. Then, Sea-Shell prototypes were fabricated using piezoceramic shells of various PZT compositions. The same four
resonance modes were also observed in the in-air admittance
spectra. This similarity verified the consistency of the FEA
and the experimental results. In water, measurements were
done after isolating the prototypes from their surroundings
using polyurethane coatings. According to TVR calculations,
peak broadening occurred at a frequency range of 60–70 kHz
for the second resonance mode. Fabrication processes require
improvements and refinement. However, as pioneering work,
the Sea-Shell design emerges as a promising candidate for
underwater applications, especially in the 50–100 kHz range,
where it would be possible to use them in a thin profile array
design.
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Mustafa Yunus Kaya received the B.S., M.S.,
and Ph.D. degrees in materials science and engineering from Gebze Technical University, Gebze,
Turkey, in 2007, 2010, and 2018, respectively.
He was a Research Assistant with the Department of Material Science and Engineering,
Gebze Technical University, from 2015 to 2018.
He was an Assistant Professor with the Department of Metallurgical and Materials Engineering,
Istanbul Gedik University, Istanbul, Turkey, from
2019 to 2020. He joined the Department of Metallurgical and Materials Engineering, Bursa Technical University (BTU),
Bursa, Turkey, in 2020, as an Assistant Professor, where he is currently an
Assistant Professor of metallurgical and materials engineering. He has
worked as a project assistant in various scientific research projects
that were supported by national funding agencies. He has coauthored
scientific articles in Science Citation Index (SCI)-covered journals. His
research interests are textured piezoceramics, piezoelectric devices and
their applications, relaxor ferroelectrics, and energy storage applications.
Sedat Alkoy (Member, IEEE) received the B.S.
degree in metallurgical engineering and the M.S.
degree in materials science from Istanbul Technical University, Istanbul, Turkey, in 1992 and
1994, respectively, and the Ph.D. degree in materials science and engineering from Pennsylvania State University, State College, PA, USA,
in 1999.
In 2000, he joined the Department of Materials Science and Engineering, Gebze Technical
University (GTU), Gebze, Turkey, as an Assistant
Professor. He was The Japan Society for the Promotion of Science
(JSPS) Fellow and the Visiting Scientist with the Nara Institute of Science
and Technology, Ikoma, Japan, from 2004 to 2006. In 2006, he got
his tenure and was promoted to an Associate Professor with GTU,
where he was promoted to a Full Professor in 2012. He is currently
a Professor of materials science and engineering with GTU. He is
also one of the two co-founders and the chief technical officer of the
spin-off company ENS PiezoDevices Ltd., Gebze. He has authored or
coauthored over 70 scientific articles in Science Citation Index (SCI)covered journals. He holds one U.S. and one Turkish patent. His research
interests include ferroelectric and antiferroelectric thin films, textured
piezoceramics, piezoceramic fibers, piezocomposites, and their device
applications. He has completed 11 research projects that were supported
by national and international funding bodies as a principal investigator
and he was also a researcher in over ten projects.