Abstract: A Nd:YAG crystal having a special structure achieved laser operation with an
extinction ratio of over 20 dB, a CW (continuous wave) average power of 6 W, a pulse width of 50
ns, and repetition rates in the range 1 kHz – 10 kHz for an output wavelength of 1064 nm for
effectively cooling the crystal for the case of laser dressing. The birefringence induced by the stress
applied to the crystal results in the production of elliptical polarization before the Brewster-window
and thus decreases the laser efficiency. In this paper, we analyzed the relationship between the
distortion and the birefringence in a Nd:YAG crystal and the resulting effect on the laser power.
Abstract: This paper describes evaluation and monitoring methods of machining characteristics
for developed cutting machine of micro grooves. Experiments were conducted under various
process conditions such as spindle revolution speed, feed rates and depth of groove. A precision
blade was manufactured to cut micro grooves in the mold of a PDP barrier rib, while taking the
groove shape into consideration. The groove cutting characteristics of the blade were evaluated by
experimenting on STD11 and cemented carbide. AE technology was used to observe the state of
the grooves. The obtained AE signals reliably represented the grooving quality and cutting
conditions, as demonstrated through the use of a fuzzy C-means algorithm.
Abstract: High accuracy and high efficiency machining of micro parts such as a
contact probe for a current inspection of semiconductor is increasingly demanded. In
this study, we have focused on a micro cutting technology of a carbon tool steel which
is a typical material for a contact probe. In order to put the precision cutting of the
high strength material into practice, it is essential to understand the micro cutting
phenomenon such as the surface texture, the tool wear with small depth of cut and low
cutting speed. Then, the precision cutting experiments of a carbon tool steel (SK105)
by titanium carbide and ultra-fine grained tungsten carbide tools were carried out with
an ultra-precision cutting machine. It was found that the feed rate, the cutting speed
and the edge sharpness of tool significantly influence the surface finish.
Abstract: This report describes fabrication of polytetrafluoroethylene (PTFE) to make up a
micro-fluidic device for the application to a Micro-Total Analysis System ( -TAS). This material is
chosen as a material of the device because of many excellent properties such as high chemical
resistance and high heat resistance in comparison with the other polymers. Mechanical micro-cutting
process is employed for the fabrications of the required elemental micro-structures such as a
micro-channel and a micro-reservoir for the device. In general, burrs are easily generated in the
cutting of soft materials such as PTFE. It is thought to be the most important to find how to prevent
the burr generation and how to clean the generated burrs to assure the device quality. Therefore, in
order to obtain the fundamental information about the burr generation in the micro-cutting of PTFE,
through hole drilling, groove milling and face milling are performed. As a result, the elemental
micro-structures without burrs are fabricated on PTFE plate. Furthermore the plate is sealed by
sealing film assisted with pressure. By testing leakage with fluid sample, it is confirmed that the
pressure-aided sealing is useful.
Abstract: The machining of metal dies involves a variety of processes that include grinding, polishing and
electrical discharge machining in addition to various cutting processes such as turning, boring, and milling.
The precise machining of complex dies, particularly in deep machining, has largely been done by
electrical discharge machining in the past, because the use of end mills and other cutting tools for such
work has been difficult. In recent years, however, problems such as low machining efficiency and the
creation of an affected layer have made the use of end mill cutting tools the general approach to this task.
In the research reported here, our objective was to establish guidelines for the optimum design of small
radius ball end mills for the deep machining of dies by systematic investigation of the cutting tool
characteristics, which is to say the rotational behavior, cutting resistance, actual rate of depth of cut and
machining accuracy of small radius ball end mills.
Here, the guidelines obtained for ultra-deep, highly-accurate machining that is applicable to machining
programs and is based on quantitative results for amounts of tool wear and tool deflection that
obtained using the optimum tool shape reported earlier are presented.
Abstract: In order to reduce the thermal influences in laser machining of sapphire surface, effects of a
short-pulse ultra-violet laser were investigated. For the UV laser, the Fifth harmonic generation (Fifth
HG) wave of an Nd:YAG laser (wavelength:213nm) was utilized. Significant reduction of thermal
damages on the surface was demonstrated with the Fifth HG pulses compared to longer wavelengths
of the Nd:YAG laser. It was shown that the control of depth of bottom surface with reduced thermal
influences was possible in lower fluence cases(less than 40 J/cm2) with a homogenized beam and
smooth surface roughness Ra < 200nm was obtainable.
Abstract: This paper proposes a new deposition method using micro electrical discharge machining
(EDM) to deposit micro spiral structure in gas. First, the basic principles of micro electrical
discharge deposition (EDD) are analyzed and the realized conditions are predicted. Then with an
ordinary EDM shaping machine, brass as the electrode, high-speed steel as the workpiece, a lot of
experiments are carried out on the micro spiral structure deposition in air. The effects of major
processing parameters, such as the discharge current, discharge duration, pulse interval, gravity and
working medium, are obtained. As a result, a 19-circle micro spiral structure with 0.19mm in
external diameter, 0.1mm in wire diameter and 3.39mm in height is deposited. Measurements show
that the deposited material has obvious delaminating structure, the components of which depend on
those of the tool electrode material, although Zn in the electrode is oxidized to ZnO. This method
establishes the research basis for micro three-dimensional deposition machining.
Abstract: In order to improve the radial superresolution of the two-photon microfabrication, the
superresolution diffraction theory was introduced in detail. The theoretical analysis of the
photosensitive resist based on the exciting power and concentration of free radical was given.. And
the superresolution diffractive optical element was applied in the two-photon microfabrication
system. Simulation results indicated that the radial superresolution of the two-photon
microfabrication can be improved with the superresolution diffractive optical element.
Abstract: As one part of the efforts to break the bottleneck of power sources in development of
integrated micro systems, a silicon based air-breathing micro direct methanol fuel cell (μDMFC)
was developed in this work. By using micro-machining technologies compatible with that in
processing of the other MEMS devices, the anode and cathode micro flow-field plates had been
successfully fabricated on a pair of 2-inch silicon wafers. The silicon μDMFC was evaluated under
ambient conditions using aqueous methanol solution with different concentrations. Results show
that open circuit potential (OCP) of the μDMFC was above to 0.6 V, and by using 3mol/L
methanol, the peak current density and power density of the silicon μDMFC could reach 28mA/cm2
and 8mW/cm2, respectively.
Abstract: Nanostructured ceramic bulk materials were achieved from nano-Al2O3 ceramic powders
via direct selective laser sintering (SLS). SLS as a non-traditional machining technology of Rapid
Prototyping was introduced and compared with other ceramic forming technologies. Scanning
electron microscopy (SEM) and X-ray diffraction (XRD) were applied to analyze the microstructure
of the ceramic bulk materials. These results demonstrated that the nano-Al2O3 ceramic powders can
be sintered into bulk materials maintained nanostructure with some technological parameters. It was
found that the nanostructured ceramic bulk exhibited unique microstructure and was free formed
rapidly by this sintering technology.