Process Performance of Silicon Thin-Film Transfer Using Laser Micro-Transfer Printing

Author(s):  
Ala’a Al-okaily ◽  
Placid Ferreira

Micro-transfer printing is rapidly emerging as an effective pathway for heterogeneous materials integration. The process transfers pre-fabricated micro- and nano-scale structures, referred to as “ink,” from growth donor substrates to functional receiving substrates. As a non-contact pattern transfer method, Laser Micro-Transfer Printing (LMTP) has been introduced to enhance the capabilities of transfer printing technology to be independent of the receiving substrate material, geometry, and preparation. Using micro fabricated square silicon as inks and polydimethylsiloxane (PDMS) as the stamp material. The previous work on the LMTP process focused on experimentally characterizing and modeling the effects of transferred inks’ sizes and thicknesses, and laser beam powers on the laser-driven delamination process mechanism. In this paper, several studies are conducted to understand the effects of other process parameters such as stamp post dimensions (size and height), PDMS formulation for the stamp, ink-stamp alignment, and the shape of the transferred silicon inks on the LMTP performance and mechanism. The studies are supported by both experimental data for the laser pulse duration required to initiate the delamination, and thermo-mechanical FEA model predictions of the energy stored at the interface’s edges to release the ink (Energy Release Rate (ERR)), stress levels at the delamination crack tip (Stress Intensity Factors (SIFs)), and interfacial temperature. This study, along with previous studies, should help LMTP users to understand the effects of the process parameters on the process performance so as to select optimal operation conditions.

2007 ◽  
Vol 353-358 ◽  
pp. 1935-1938 ◽  
Author(s):  
Yasuhiro Yamazaki ◽  
T. Kinebuchi ◽  
H. Fukanuma ◽  
N. Ohno ◽  
K. Kaise

Thermal barrier coatings (TBCs), that reduce the temperature in the underlying substrate material, are an essential requirement for the hot section components of industrial gas turbines. Recently, in order to take full advantage of the potential of the TBC systems, experimental and analytical investigations in TBC systems have been performed. However there is a little information on the deformation behavior of the top coating. In addition, the effects of the thermal exposure and the process parameters on the mechanical properties of the top coating have never been clarified. From these backgrounds, the effects of the process variables in APS and the thermal exposure on the mechanical properties were investigated in order to optimize the APS process of top coatings. The experimental results indicated that the mechanical properties of the APS-TBC, i.e. the tensile strength and the elastic modulus, were significantly changed by the process variables and the long term thermal exposure. The microstructural investigation was also carried out and the relationship between the mechanical properties and the porosity was discussed.


2013 ◽  
Vol 634-638 ◽  
pp. 382-385
Author(s):  
Ke Guo Liu ◽  
Li Li Gu ◽  
Hui Guang Hu ◽  
Rong Yang ◽  
Jun Tao

The experimental studies for purification of 1,8-cineole by vacuum batch distillation as well as the application of additives in 1,8-cineole purification were carried out. There were two steps during the purification. In the first step, experimental results showed that the optimal operation conditions for purification of 1,8-cineole were the temperature of the reboiler at about 320.15 K under a certain vacuum degree. In the second step, the optimal operation temperature of the reboiler was 331.15 K. The optimal reflux ratio was generated finally. Vacuum degree was controlled between 1.1 kPa and 1.3 kPa.


2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Satu Ojala ◽  
Ulla Lassi ◽  
Paavo Perämäki ◽  
Riitta L. Keiski

Catalytic oxidation is a feasible and affordable technology for solvent emission abatement. However, finding optimal operation conditions is important, since they are strongly dependent on the application area of VOC incineration. This paper presents the results of the laboratory experiments concerning four most central parameters, that is, effects of concentration, gas hourly space velocity (GHSV), temperature, and moisture on the oxidation of n-butyl acetate. Both fresh and industrially aged commercial Pt/Al2O3catalysts were tested to determine optimal process conditions and the significance order and level of selected parameters. The effects of these parameters were evaluated by computer-aided statistical experimental design. According to the results, GHSV was the most dominant parameter in the oxidation of n-butyl acetate. Decreasing GHSV and increasing temperature increased the conversion of n-butyl acetate. The interaction effect of GHSV and temperature was more significant than the effect of concentration. Both of these affected the reaction by increasing the conversion of n-butyl acetate. Moisture had only a minor decreasing effect on the conversion, but it also decreased slightly the formation of by products. Ageing did not change the significance order of the above-mentioned parameters, however, the effects of individual parameters increased slightly as a function of ageing.


Author(s):  
Sayed A. Nassar ◽  
Amir Kazemi

Experimental and finite element techniques are used for investigating the effect of cyclic thermal loading on the clamp load decay in preloaded single-lap bolted joints that are made of multimaterial lightweight alloys. Substrate material combinations include aluminum, magnesium, and steel, with various coupon thicknesses. The range of cyclic temperature profile varies between −20 °C and +150 °C in a computer-controlled environmental chamber for generating the desired cyclic temperature profile and durations. Real time clamp load data are recorded using strain gage-based, high-temperature, load cells. Clamp load decay is investigated for various combinations of joint materials, initial preload level, and substrate thickness. Thermal and material creep finite element analysis (FEA) is performed using temperature-dependent mechanical properties. The FEA model and results provided a valuable insight into the experimental results regarding the vulnerability of some lightweight materials to significant material creep at higher temperatures.


2004 ◽  
Vol 58 (12) ◽  
pp. 563-568 ◽  
Author(s):  
Mihajlo Stankovic ◽  
Nadica Stojanovic ◽  
Nada Nikolic ◽  
Vesna Novkovic

The kinetics of extraction of total lipids from ground parsley (Petroselinum crispum (Mill.) Nym. ex. A.W. Hill) seeds with a mixture of ethanol or methanol with non-polar organic solvents, chloroform, carbon tetrachloride, trichloroethylene and petroleum ether, at various temperatures were studied. The maceration technique with reflux was used. The kinetic parameters were determined in extraction kinetic equations, as well as the optimal operation conditions for total lipids extraction. The maximum total lipids yield under optimal conditions was 33.7 g per 100 g of dry parsley seeds. Nine lipid fractions of the total lipids were separated by thin layer chromatography among which were phospholipids, sterol, mono-, di- and triacylglycerol, free fatty acids and carbohydrates.


2022 ◽  
pp. 66-83
Author(s):  
Qingjiao Zhu ◽  
Xintong Guo ◽  
Yanan Guo ◽  
Jingjing Ma ◽  
Qingjie Guo

With the acceleration of industrialization and urbanization in China, wastewater treatment is increasing yearly. As a by-product of wastewater treatment, the gasification of sludge with coal in chemical looping process is a clean and efficient conversion technology. To explore the reaction behavior of cogasification of sludge and coal with iron-based oxygen carriers (OCs) for producing hydrogen-rich syngas, the experiment of cogasification using Fe2O3/Al2O3 as OC in a fluidized bed reactor was conducted. The result showed that the volume percentage of hydrogen (H2) and syngas yield is proportional to the amount of sludge added. The optimal operation conditions were: temperature at 900 °C, the mass ratio of OC to coal at 5.80 and mass ratio of sludge to coal at 0.2. Under this operating condition, the volume percentage of H2 and syngas yield in the flue gas was 75.6 vol% and 97.5 L·min-1·kg-1, respectively. Besides, the OC showed a stable reactivity in the sixth redox cycle with added sludge. However, the reactivity of OC significantly declined in the seventh and eighth redox cycles. It was recovered when the ash was separated. The decrease in the specific surface area of the OC caused by ash deposition is the main reason for the decline in its reactivity. The kinetic analysis showed that the random pore model describes the reaction mechanism of sludge/coal chemical looping gasification (CLG). The addition of sludge can reduce the activation energy of coal CLG reaction, accelerate the gasification reaction rate and increase the carbon conversion.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3920 ◽  
Author(s):  
Mariangela Quarto ◽  
Giuliano Bissacco ◽  
Gianluca D’Urso

Several types of advanced materials have been developed to be applied in many industrial application fields to satisfy the high performance required. Despite this, research and development of process suited to machine are still limited. Due to the high mechanical properties, advanced materials are often considered as difficult to cut. For this reason, EDM (Electrical Discharge Machining) can be defined as a good option for the machining of micro components made of difficult to cut electrically conductive materials. This paper presents an investigation on the applicability of the EDM process to machine ZrB2 reinforced by SiC fibers, with assessment of process performance and energy efficiency. Different fractions of the additive SiC fibers were taken into account to evaluate the stability and repeatability of the process. Circular pocket features were machined by using a micro-EDM machine and the results from different process parameters combinations were analyzed with respect to material removal, electrode wear and cavity surface quality. Discharges data were collected and characterized to define the actual values of process parameters (peak current, pulse duration and energy per discharge). The characteristics of the pulses were used to evaluate the machinability and to investigate the energy efficiency of the process. The main process performance indicators were calculated as a function of the number of occurred discharges and the energy of a single discharge. The results show interesting aspects related to the process from both the performances and the removal mechanism point of view.


2019 ◽  
Vol 12 ◽  
pp. 117862211988048 ◽  
Author(s):  
Erick R Bandala ◽  
Oscar M Rodriguez-Narvaez

Cavitation is considered a high energy demanding process for water treatment. For this study, we used a simple experimental setup to generate cavitation at a low pressure (low energy) and test it for hydroxyl radical production using a well-known chemical probe as a hydroxyl radical scavenger. The conditions for generating the cavitation process (eg, pressure, flow velocity, temperature, and other significant variables) were used to degrade model contaminants, an azo dye and an antibiotic. The amount of hydroxyl radicals generated by the system was estimated using N,N-dimethyl-p-nitrosoaniline (pNDA) as hydroxyl radical scavenger. The capability of hydrodynamic cavitation (HC) to degrade contaminants was assessed using Congo red (CR) and sulfamethoxazole (SMX) as model contaminants. Different chemical models were analyzed using UV-visible spectrophotometry (for pNDA and CR) and high-performance liquid chromatography (HPLC) (for SMX) after HC treatment under different process conditions (ie, pressure of 13.7 and 10.3 kPa, and flow rates of 0.14 to 3.6 × 10−4 m3/s). No pNDA bleaching was observed for any of the reaction conditions tested after 60 minutes of treatment, which suggests that there was no hydroxyl radical generation during the process. However, 50% degradation of CR and 25% degradation of SMX were observed under the same process conditions, comparable with previously reported results. These results suggest that the process is most likely thermally based rather than radically based, and therefore, it can degrade organic pollutants even if no hydroxyl radicals are produced. Hydrodynamic cavitation, either alone or coupled with other advanced water technologies, has been identified as a promising technology for removing organic contaminants entering the water cycle; however, more research is still needed to determine the specific mechanisms involved in the process and the optimal operation conditions for the system.


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