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Prof.
Mikio Ito
Fukui University of Technology
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Speech Title:
Fabrication of Diamond Particle Dispersed Metal Matrix Composites by
Spark Plasma Sintering(SPS) for high thermal conductive materials
Abstract: TBA
Biography:
Prof. Mikio Ito received B.E., M.E, and Dr.E degrees from Osaka
University. He was an assistant professor and associate professor at
Osaka University, and is now a professor of Department of Mechanical
Engineering, Fukui University of Technology. His research interests
include development of novel powder metallurgy process, especially for
sintering process, and improvement of various
powder-metallurgy-processed functional materials, such as thermoelectric
and hard magnetic materials, etc.
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Prof.
Chih-Lang Lin
Central Taiwan University of Science and Technology |
Speech Title:
Study of the Factors on Controlling Cured Layer Thickness in DLP
3D Printing
Abstract:
Digital Light Processing (DLP) 3D
printing is an additive manufacturing technique that uses a digital
light projector to cure photopolymer resin layer-by-layer to create
high-precision solid structures. In addition to the planar resolution,
the control of curing depth has a critical impact on the success of
precise printing and the geometric features of the printed product. This
issue is aggravated in the case of projection micro-stereolithography
(PμSL), which uses an objective lens to enhance the planar resolution of
the projected pattern. In this study, we investigated possible measures
to control the cured layer thickness from both material and optical
perspectives. As-received commercial resin was used to obtain the raw
cured layer thickness, and then Sudan I or carbon black was added
separately to study their effects. Eventually, the grayscale of the
exposed pattern was adjusted to reduce light intensity and achieve a
thinner layer thickness. Combining the above measures reduced the
single-layer cured thickness from the raw 250 μm to 5.8 μm, approaching
the usual minimum layer dimension setting of 5 μm. By exploring the
variables affecting cured layer thickness, this study is expected to
improve DLP 3D printing technology in producing high resolution
structures.
Biography:
Dr. Chih-Lang Lin got his master’s degree in Power Mechanical
Engineering from National Tsing-Hua University. He earned his Ph.D. in
Mechanical Engineering from National Taiwan University. In the mean
while, he earned another Ph.D. in Physics of Condensed Material and
Radiation from Joseph Fourier University, France. His thesis involves
two subjects which are fiber Bragg grating (FBG) sensors and laser
driven microsensors. In the first part, a framework for the
interpretation of reflected FBG spectra under a non-uniform strain field
is proposed and experimental results for a crack tip strain field are
presented. In the second part, the fabrication of laser driven polymer
microsensors for visconsimetry, velocimetry and micropump applications
are developed. Before he created the Bio-Photonics Lab at Central Taiwan
University of Science and Technology, he joined Air Liquide
international group to work in Japan as a researcher (TFT/LCD group) and
in Taiwan as an operation manager/factory director. One of Dr. Lin’s
research interests is laser driven micromachines. He proposed a serious
of elemental micromachines, such as cantilever, lever beam, spring,
Archimedes screw…etc. His another interest is the fabrication of
three-dimensional structured protein using two-photon polymerization
technology for detecting bio-cells such as bacteria, red blood cells,
and cancer cells. Also, he studied the bio-mechanics of cells by using
optical tweezers for the clinical diagnosis. The above subjects were
expected to contribute to the application of point-of-cares. More
recently, he starts to implement the intelligent manufacture by the 3D
printing technique.
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Assoc.
Prof.
Go Yamamoto
Tohoku University
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Speech Title:
Can strength prediction methods based on continuum mechanics be applied
for unidirectional carbon nanotube yarn reinforced plastic composites?
Abstract: Carbon nanotubes (CNTs) having a high elastic
modulus and tensile strength are anticipated for use as a reinforcing
agent in fiber reinforced composites. Recently, the focus has shifted to
investigating the fracture mechanisms of CNT yarns, which are twisted
together to form long threads of CNTs, particularly in polymer matrix
environments. In this study, the interaction between CNT yarns in
polymer matrix environment under tensile loading was observed using the
X-ray computed tomography (CT) method at the synchrotron radiation
facility, SPring-8. Double-fiber fragmentation specimens were prepared
by positioning two yarns parallel to the loading direction, implementing
an inter-yarn spacing of within 20 μm. X-ray CT nanoimaging revealed
that the CNT yarns fractured closely together in the direction of the
long axis of the CNT yarns. This implies that stress concentration
occurred in the adjacent CNT yarn due to the fracture of the CNT yarn,
as observed for unidirectional carbon fiber reinforced plastic (CFRP)
composites. Moreover, the fracture surfaces of the individual CNT yarns
were observed to be separated by the relative slippage of CNT bundles.
The matrix crack propagated longitudinally within the CNT yarns, taking
a helical path through the matrix. Our findings revealed that stress
concentration on the adjacent CNT yarn is expected to occur, providing
valuable insight into the similarity of the failure mechanisms between
unidirectional CNT yarn composites and unidirectional CFRPs.
Biography:
Dr. Go Yamamoto obtained his PhD degree from Tohoku University (Japan)
in 2006. He is currently an Associate Professor in Department of
Aerospace Engineering, Tohoku University, Japan. His group research
interests include (1) Tensile strength prediction of carbon fiber
reinforced plastic composites, (2) Determination of elastic constants of
materials with intricate 3D geometries and mechanical anisotropy, and
(3) Development of defect detection method by using topology
optimization. Some of the work has been published in Composites Part A,
Carbon, and Nanotechnology, among others.
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