Abstract: Recently the polymeric LOC (lab-on-a-chip) has been developed by the bio technology
and the micro electro mechanical system technology. It is possible that biological experiment and
analysis is executed rapidly and easily using a simple specimen. Therefore, many researches on
LOC are progressing actively in various fields such as medical, biotechnical, environmental aspects
etc. Up to the present time, most of polymeric LOC has been manufactured by LIGA (lithograpie
galvanofomung abformung) or chemical etching processes. However, these methods have several
disadvantages which are the complicated fabrication stages, requirements for various special
equipments and limitations of materials. In this study, in order to overcome these difficulties, the
possibilities of micro fluidic channel features were executed by micro cutting process for the steel.
So the micro mold insert with micro fluidic channel was designed and manufactured by micro
cutting process for the injection molding.
Abstract: In this study, stainless steel material (X5CrNi1810) was micromachined by chemical
etching method. Ferric chloride was selected as etchant which is the most widely used etchant for
iron-based materials. Four different etchant concentrations (32 °Bé, 36 °Bé, 40 °Bé and 44 °Bé)
were used at various etching temperature. Moreover, the influence of the addition of hydrochloric
acid to main etchant on etching performance was examined. The aim of this study was to
investigate the depth of etch and surface roughness affected by etchant concentration, hydrochloric
acid addition and etching temperature. It was observed that etching temperature for any etchant
concentration is important factor in case of depth of etch and surface roughness. It was also noticed
that the addition of hydrochloric acid to main etchant increased depth of etch value at any etching
temperature. The optimum etching parameters were obtained for the chemical etching of stainless
Abstract: With advances in micro fuel cell development, the production of hydrogen for micro
reformer has become increasingly important. However, some problems regarding the micro
reformer are yet to be resolved. These include reducing the size, reducing the quantity of CO and
combining the fuel cell, among others. Accordingly, in this investigation, a micro temperature
sensor and a heater are combined inside a stainless steel-based micro reformer to measure and
control the temperature and thus improve performance and minimize the concentration of CO.
In this work, micro-electro-mechanical-systems (MEMS) of the micro channel type are
fabricated on a stainless steel substrate to enhance the methanol conversion ratio. The micro
temperature sensor and heater are made of gold and placed inside the micro reformer. Although the
micro temperature sensor and heater have already been used to measure and control temperature in
numerous fields, they have not been employed in micro reformer and commercial products.
Therefore, this study presents a new approach for integrating a micro temperature sensor and heater
in a stainless steel-based micro reformer to minimize the size and improve performance.
Abstract: This investigation utilizes porous silicon as the gas diffusion layer (GDL) in a micro fuel
cell. Pt catalyst is deposited on the surface of, and inside the porous silicon, to improve the
performance of a fuel cell, and the Pt metal that remains on the rib is used to form a micro thermal
sensor in a single lithographic process. Porous silicon with Pt catalyst replaces traditional GDL, and
the relationships between porosity and pore diameter, and the performance of the fuel cell are
In this work, electrochemical etching technology is employed to form porous silicon to replace
the gas diffusion layer of a fuel cell. This work focuses on porous silicon with dimensions of tens of
micrometers. Porous silicon was applied to the gas diffusion layer of a micro fuel cell. Boron-doped
20 '-cm n-type (100)-oriented doubly polished silicon wafer was used on both sides. The process is
performed to etch a fuel channel on one side of a silicon wafer, and then electrochemical etching
was adopted to form porous silicon on the other side to fabricate one silicon wafer that combines
porous silicon with a fuel channel on a silicon wafer to minimize a fuel cell. The principles on
which the method is based, the details of fabrication flows, the set-up and the experimental results
are all presented.
Abstract: The temperature and humidity conditions of a membrane electrode assembly (MEA)
determine the performance of fuel cells. The volume of traditional temperature and humidity
sensors is too large to allow them to be used to measure the distribution of temperature and
humidity in the MEA of fuel cells. Measurements cannot necessarily be made where required. They
measure only the temperature and humidity distribution outside the fuel cells and yield results with
errors that exceed those of measurements made in MEA.
Therefore, in this study, micro-electro-mechanical-systems (MEMS) fabrication technology was
employed to fabricate an array of micro sensors to monitor in situ the temperature and humidity
distributions within the MEA of fuel cells. In this investigation, an array of micro temperature and
humidity sensors was made from gold on the MEA. The advantages of array micro gold
temperature and humidity sensors are their small volume, which enable them to be placed on MEA
and their high sensitivity and accuracy. The dimensions of the temperature and humidity sensors are
180μm × 180μm and 180μm × 220μm, respectively.
The experiment involves temperatures from 30 to 100 °C. The resistance varied from 23.084 to
28.196 /. The experimental results reveal that the temperature is almost linearly related to the
resistance and the accuracy and sensitivity are less than 0.3 °C and 3.2×10-3/°C, respectively. The
humidity sensor showed that the capacitance changed from 15.76 to 17.95 pF, the relative humidity
from 20 to 95 %RH, and the accuracy and sensitivity were less than 0.25 %RH and 0.03 pF/%RH.
Abstract: The fuel cell has the potential to become an indispensable source of electric power.
However, some problems have not yet been resolved. Measuring the temperature and humidity
inside the fuel cells is currently difficult. Accordingly, in this study, micro sensors were fabricated
within the fuel cell, in which the temperature and humidity distributions were measured.
The substrate of the fuel cell was made of stainless steel (SS-304) and etching was employed to
fabricate the channel on the stainless steel substrate. Then micro-electro-mechanical-systems
(MEMS) technology was used to fabricate the array micro temperature and humidity sensors on the
rib of channel of stainless steel. The advantages of array micro temperature sensors are their small
volume, their high accuracy, their short response time, the simplicity of their fabrication, their mass
production and their ability to measure the temperature at a precise location more effectively than
the traditional thermocouple. The micro humidity sensors were made from gold and titanium as
down and up electrodes in the channel. The performance curve of the single cell was operating at
41.54 °C and gas flow rates of H2/O2 at 200/200ml/min. The max power density of the bipolar with
micro sensor was 56 mW/cm2.
Abstract: This study used the Al2O3 nano-lubricant produced from the direct synthesis method was
used as the experimental samples and the ultrasonic vibration was used for dispersing the
nanoparticles into three types of the weight fraction (0.1, 0.2, 0.3%wt). The base solvent was the
lubricant of vacuum pump. The objectives of this study were to discuss the dependence of operating
temperature of vacuum pump under the various weight fraction of Al2O3 nanoparticles. In this
experiment we added Al2O3 nano-lubricant into the direct drive oil sealed rotary vacuum pump, and
used the thermocouple measure the temperature on the four test points (cylinder, in-lubricant, case
of vacuum pump and discharge pipeline). The results show that the cylinder temperature was
reduced by 1.3% and increased by 0.4%, 1.8%, the lubricant temperature was increased by 5.3%,
0.5% and 1.9%, the case surface temperature was reduced by 1.7%, 1.4% and 1.5%, and discharge
pipeline temperature was reduced by 0.6%, 2.1% and 3.8% respectively when the sample fractions
were 0.1%, 0.2% and 0.3%wt. From the results, it could be realized that the nano-lubricant has
more effects on increasing the performance of heat sink than conventional lubricant.
Abstract: The recursive projection schemes used in most existing recursive methods for solid
deformable structure dynamic problems in precision manufacturing systems lead to dense
coefficient matrices in the acceleration equations and consequently there is a strong dynamic
coupling between the joint and elastic coordinates. When the number of elastic degrees of freedom
in engineering materials increases, the size of the coefficient matrix in the acceleration equations
becomes large and consequently the use of these recursive methods for solving the joint and elastic
accelerations becomes less efficient. This paper discusses the problems associated with the recursive
projection schemes used in the existing recursive methods, and it is shown that decoupling the joint
and elastic accelerations using the nonlinear recursive method requires the factorization of nonlinear
matrices whose dimensions are independent of the number of elastic degrees of freedom of the
multibody system. An amalgamated formulation that can be used to decouple the elastic and joint
accelerations for different multibody manufacturing systems is then proposed. The use of the
nonlinear recursive method developed in this paper is demonstrated using the open-loop and closedloop
chains in precision manufacturing systems.
Abstract: The liquid flow in nanoscale channel under thermal gradient, or so-called thermal
transpiration, is studied by Molecular Dynamics Simulation. The phenomenon was realized in two
fluid systems which differed from each other in the methods for applying the temperature gradient.
One used heat source and the other wall-heating. The channel was periodic and its walls consisted
of two different materials: conducting, high energy wall and non-conducting slip wall. It is shown
that the liquid in a periodic channel can effectively be driven by the thermal transpiration. Various
characteristics of the flow are discussed that include the temperature gradient, velocity profile and
liquid structure in the channel.
Abstract: Due to lack of desirable mechanical properties of silicon substrate; the current trend of
micro-fabrication technology is towards metallic materials. In this study, the electrochemical micromachining
(EMM) technology is developed to fabricate micro-scale flow channels on thin metallic
316L stainless steel plate. The cathode electrode, the tool, is the mirror image of flow channels. It
was produced by the MEMS and UV-LIGA technology and the size is 200μm in width and 500μm
in height for the intension to fabricate a serpentine flow channel of 200μm in both depth and width.
Because of the electrode size, the process control parameters and geometrical features surpassed
conventional and CMOS methods. The flow channels on 0.6mm thick SS 316L plates were
fabricated by EMM process within 30 seconds with effective area of 625mm2. The dimensions of
flow channel were varying from 1504m to 5004m in width and about 2004m in depth. The results
demonstrate the EMM technology produces good quality metallic flow channels efficiently.