This study investigated effects of energy levels, pulse durations, and pulse frequencies during an IPL (Intense Pulsed Light) sintering process on surface morphology and resistance of screen-printed Ag patterns on PET substrates. Surface characteristics, including primary profile (Pa), roughness (Ra), thickness, and sheet resistance, were measured before and after sintering. At fixed energy levels (13.18, 32.96, and 46.14 kW), increasing pulse counts (2, 5, and 7) at 6 ms durations significantly increased Pa and thickness, while Ra was not changed. In contrast, higher pulse counts (4, 10, and 14) at 3 ms durations improved surface roughness by reducing Ra. Statistical analysis (Paired T-test) confirmed these results. Sheet resistance analysis showed that lower pulse counts at 6 ms caused greater variability in resistance, stabilizing with higher counts. At 3 ms, surface resistance decreased with higher pulse counts, showing reduced variability. These results suggest that adjusting pulse conditions and counts during the sintering process can optimize both electrical properties and uniformity. Additionally, morphological changes before and after sintering indicated that these adjustments might influence upper-layer printability in multilayer printing. The study highlights the importance of considering both functional and morphological characteristics during sintering for optimized production of printed electronic devices.

In soft robotics, gripper technology based on granular jamming offers the capability to adapt flexibly to objects of diverse shapes and material properties. Specifically, small-scale jamming grippers can address tasks challenging for conventional grippers either by enhancing gripping performance or by extending functionality when combined with rigid grippers. This study investigated effects of membrane morphology, thickness, and material on performances of small-scale jamming grippers to identify optimal design parameters. Experiments were conducted with three membrane morphologies, two thickness levels, and two material types. Results indicated that a concentric-pocket membrane morphology, a membrane thickness of 1.5 mm, and a soft material such as Dragon Skin 10 achieved a superior holding force of 430.7 gf. These findings indicate that softer materials can improve the membrane's ability to conform to objects, while increasing thickness can minimize deformation due to tensile forces, thereby enhancing gripping stability. Furthermore, experiments demonstrated that this configuration could enable the gripper to safely grasp objects of various shapes and perform additional tasks, such as rotating valves and handles, with effectiveness.

Rolling bearing fatigue life is an essential criterion in industrial equipment design and manufacturing and requires precise maintenance and replacement predictions. ISO/TS 281:2007 and 16281:2008 are commonly used for angular contact ball bearing (ACBB) fatigue life calculations, but they do not account for the characteristics of individual bearing elements under combined loading conditions. This study proposes an enhanced formula for calculating fatigue life modification factors that considers individual element-specific contact loads and resulting film thickness variations. The proposed fatigue life formula provides longer life predictions than the conventional method of determining modification factors based solely on maximum contact loads. This difference is particularly noticeable in low-speed and/or heavy-loading applications. Analysis conducted using the proposed fatigue life formula on various factors affecting fatigue life revealed that fluid kinetic viscosity coefficients, temperature-associated density changes, and changes in radial loads and rotational speeds could significantly impact the fatigue life of ACBBs. The proposed fatigue life formula is expected to increase the accuracy of ACBB fatigue life predictions.

In this study, we fabricated thin film solid oxide fuel cells on nanoporous anodic aluminum oxide (AAO) substrate for low-temperature operation using the all-through sputtering method. To deposit up to a three-micrometer thick anode with both porosity and electrical conductivity, we used the glancing angle deposition and co-sputtering methods. For the anode materials, we used nickel gadolinium-doped-ceria (Ni-GDC) mixed ionic and electronic conductor (MIEC), which improved hydrogen oxidation reaction reactivity at the anode side. TF-SOFCs were successfully operated at 500℃, and 223.6 mW/cm² was their highest measured maximum power density. We conducted structural and electrochemical analyses to figure out cells’ unique resistant characteristics; ohmic resistance through the anode thin film and polarization resistance of reaction area near the narrowed anode pores. We found how the anode thin film thickness affects the current collecting performance and the anode reactivity, and their effects were qualitatively and quantitatively compared.

Most of the consumables used in the CMP (Chemical Mechanical Planarization) process are discarded because it is difficult to reuse them. Slurry accounts for most of the consumables, so research is being conducted to reduce the amount of slurry used. A previous study explains that when the same amount of slurry is injected, the material removal rate is improved when the slurry is injected wide and thin instead of the tube nozzle, which is the conventional slurry injection method. However, there was no change in the injection method due to the problems of the injection method suggested in previous studies and the lack of follow-up studies. Thus, in this paper, an injection method through an ultrasonic spray nozzle is proposed to improve the problems of the injection method proposed in previous studies. Additionally, it is intended to calculate the slurry film thickness according to the spraying range and to explain the effect of the film thickness on the material removal rate.

Three-dimensional (3-D) printing, with its capability for producing arbitrary shapes, has shown great potential for usage in patient-specific tissue engineering. However, if artificial tissues are fabricated directly through typical 3-D printing processes, the mechanical properties, particularly for softness or flexibility, significantly differ from those of natural tissues, resulting in inappropriate side effects during surgeries using vascular grafts. However, this can be overcome through the indirect 3-D printing of templates created with a thin-film formation process, such as dip coating. Dip coating is performed in two steps, including dipping/withdrawing a target base template from a polymer solution, and then drying the solvent into a solid thin film on the template. However, it is difficult to form a uniform layer on the arbitrary template because the gravitational flow of the coated solution disturbs the uniformity of the template as the solvent is drying. Therefore, we minimized the flow around the template after dip coating by rapidly removing the solvent removal by dipping the solution-coated template into ethanol. This reduced the solvent removal time and increased the viscosity of the coated solution, thereby alleviating the gravitational flow of the coated solution, and allowing us to successfully fabricate flexible vascular grafts.

Many countries are trying to overcome global warming due to greenhouse gas emissions, such as CO₂. In particular, the regulation on CO₂ emissions of internal combustion engine vehicles has become strictly important. Thus, the automobile companies are putting more effort for improving the manufacturing of the battery, which is the main power supply of electrical vehicles. In the electrode cutting process, laser cutting has been actively discussed to solve problems originating from the conventional electrode cutting processes. However, there is a lack of research considering the effect of thickness of the active material on laser cutting. In this paper, the effect of thickness of the active material on laser cutting of electrodes is analyzed. First, the cut electrodes are observed through a scanning electron microscope (SEM). Next, the kerf width and clearance width of the electrodes are measured and compared at the same laser parameter. The kerf width and clearance width of relatively thick electrodes are narrowly formed. Finally, the cutting quality of the electrode is compared. A uniform cut edge is observed as the scanning speed increases.

This study focuses on these issues and includes the static fracture experiments with two forms of specimens; aluminum foam DCB and TDCB bonded with the type of mode III, a simulation static analysis to verify this experiment, and analysis of fracture behavior of adhesive interface of structures attached with aluminum foam by shape and thickness. The thickness of DCB and TDCB specimens designed in this study are set as variable t, and each thickness is t = 35 mm, 45 mm, 55 mm. According to forced displacements, the maximum reaction forces of DCB specimens due to thickness were approximately 0.35 kN, 0.45 kN, 0.54 kN, and the maximum reaction force of TDCB were approximately 0.4 kN, 0.52 kN, and 0.63 kN respectively. We expect the data according to variables to be easily investigated without a separate testing process, and effective analysis of the mechanical characteristics of aluminum foam DCB and TDCB.

This study investigated the role of multi-layer lever type flexure hinges for high magnification of piezoelectric actuators and their optimal design. In order to obtain a displacement higher than 700 μm with a common PZT actuator of displacement less than 15 μm, the magnification ratio of a flexure hinge must be at least 50 or higher. Under a limited compact space, a multi-layer lever structure represents a useful alternative. Restricting the important design parameters to the number of layers and rotational stiffness of notch, the maximum required input displacement/force and the maximum output displacement were analyzed according to the number of layers. The two-layer structure was selected as the best option for large magnification ratio because the required input displacement was drastically reduced. FEM analysis revealed that the lever thickness should be larger than 12 mm to exhibit a rigid body behavior. The output displacement was 664 μm, which was less than 704 μm expected in the design stage. It might be attributed to elastic deformation of the notches of 1st and 2nd layers, which was not considered in the design stage.

Three-dimensional (3D) scanning processes have been applied to a wide range of manufacturing industries for inspection and reverse engineering. Especially, optical scanning method is used mostly as a non-contact scanning technique in manufacturing field. However, it can be influenced from surface characteristics such as transparency and reflectivity. To resolve these problems, various coating techniques have been studied for years. Among them, atomization-based coating method is one of the key technologies to change its characteristics before scanning the objects. In this study, atomizationbased spray coating system is developed for producing a uniform thin layer. Then, a series of experiments are conducted to evaluate the coating performance with the developed coating system. As a result, after coating the surface of transparent and shiny target objects: glass slide, colour sample, cell cover, and clutch lever, 3D scanning results show that a uniform coating of target objects is significantly improved. Its coating thickness is less than 1 μm which means that it is important to keep the geometry unchanged of the part.

This study proposes a method for identifying correlations between tension and drop height for sessile droplets in a roll-toroll processing system. The effect of tension and drop height on the contact angle of a sessile droplet is presented. Design of experiment (DOE) methodology and statistical analysis are used to define a correlation between the process parameters. The contact angle is decreased while increasing tension and drop height. The influence of the tension is less significant on the contact angle compared with the effect of the drop height. However, tension should be considered as a major parameter because it is not easy to fix with roll eccentricity and compensating speed of the driven roll. The results of this study show that the effect of tension on the contact angle of a sessile droplet is more important than drop height because the drop height is fixed when the process systems are determined.