Recently, lightweight materials centered on the future mobility industry are used in various parts such as battery housings and EV platform frames to improve fuel efficiency of automobile engines. Polycrystalline Diamond (PCD) tools are in demand by parts processing companies to improve productivity for machining lightweight parts. PCD drills have excellent cutting performance and wear resistance in high-speed machining. They are expected to grow in the global cutting tool market in the future. Research is needed to improve their performance. In this study, PCD gun drill and twist drill were respectively manufactured using brazing technology. Comparative machining experiments were then conducted. The PCD gun drill is a straight-shaped tool with a PCD tip brazed to a tool body groove for the tip to enter the cutting edge. The PCD twist drill is a spiral-shaped tool with a PCD drill blank brazed to a V-shaped butt joint with the tool body and an internal groove. Both PCD drills were successfully manufactured and evaluated for dimensional accuracy and surface quality by machining aluminum alloy materials with MCT equipment. In the future, we will evaluate not only aluminum materials, but also various machining materials.

A lamb wave propagation behavior on a freestanding nanoscale membrane was investigated using a laser ultrasonic technique in the present study. A 110-nm thick aluminum (Al) layer was deposited on a rectangular 200-nm thick silicon nitride (SiN) membrane and the Lamb wave was launched using a pulsed laser. The transfer matrix technique was employed to obtain a theoretical dispersion curve so that material properties of the SiN membrane could be estimated through curve-fitting. In addition, picosecond ultrasonic measurement was used to characterize the Al film. Results showed that the dispersive behavior of Lamb wave in the fundamental antisymmetric mode could be clearly observed on the membrane. However, comparison of dispersion curves indicated that the effect of residual stress of the film became more influential at a low dimensional scale.

In this study, we introduce a novel flash light sintering (FLS) method to address the issue of secondary phase formation in conventional high-temperature thermal sintering processes. The microstructure and cross section of the Lanthanum strontium cobalt (LSC) air electrode were analyzed using field emission scanning electron microscopy (FE-SEM). The presence of secondary phases was evaluated using X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) in SEM. Electrochemical performance was assessed using NiO-YSZ anode-supported LSC cathode cells at 750oC. The maximum power density of the thermally sintered LSC cathode at 900oC was 272.4 mW/cm², while the flash light sintered LSC cathode by 18.5 J/cm² achieved 2,222 mW/cm². These results demonstrate that the flash light sintering process can effectively prevent secondary phase formation and successfully sinter the electrode, thereby enhancing the performance and reliability of SOFCs.

This paper extensively explores and analyzes the latest research trends in Ionic Polymer-Metal Composites (IPMC) sensors. IPMC sensors are known for their flexibility, lightness, and high responsiveness. They show great promise across different fields. They can respond sensitively to various stimuli such as mechanical deformation, humidity, and pressure, making them ideal for bio-responsive detection, health monitoring, and energy harvesting. This paper introduces actuation and sensing mechanisms of IPMCs, discusses their manufacturing processes, and explores how these processes can influence the responsiveness and stability of sensors. Moreover, through case studies of IPMC-based research that can perform self-sensing functions, it presents possibilities brought by the integration of sensors and actuators. This paper emphasizes the potential for research and development of IPMC sensors to expand into various industrial fields and explores ways to continuously improve the accuracy and reliability of sensors. IPMC-based sensors are expected to play a significant role in advancing medical devices and wearable technologies, thereby facilitating innovation in the field.

Microfluidic chips have become a critical component in advanced applications such as biochemical analysis, medical diagnostics, drug development, and environmental monitoring because of their ability to precisely control fluid flow at the microscale. The functionality of these chips is highly dependent on the precision and dimensional stability of microchannel structures formed on them. While injection molding is an efficient method for a mass production of microfluidic chips, it is required to minimize undesirable deformation due to thermal and mechanical stresses, which can degrade the overall performance. This study investigated global (Macro-scale) and local (Micro-scale) deformation behaviors of injection-molded microfluidic chips. Effects of processing parameters, including mold temperature, melt temperature, filling time, and packing pressure, were investigated. The Taguchi-based design of experiments approach was employed to systematically analyze these effects and to determine optimal conditions to minimize deformation.

As the global manufacturing industry moves toward carbon neutrality, improving energy efficiency of machine tools has become essential. Although machine tools contribute significantly to industrial energy consumption, systematic methods for evaluating their energy consumption remain insufficient. To address this issue, this study developed an energy consumption evaluation system based on ISO 14955, the international standard for machine tool energy efficiency. The proposed system enabled a detailed analysis of energy usage patterns in different operating states, identifying key areas for energy reduction. The developed system could measure energy consumption of individual machine tool components in various operating states using power meters and automatically generates reports. This allows users to identify which components and operating states consume the most energy. We tested and validated this system on three different machine tools and analyzed strategies for reducing energy consumption. The developed evaluation system can help machine tool manufacturers integrate it into their equipment, develop energy-efficient technologies, and contribute to sustainable manufacturing.

Degradation of proton exchange membrane fuel cells (PEMFCs) can be accelerated by impurities in the air. In maritime environments in particular, sodium chloride (NaCl) can reduce the performance of membrane electrode assembly (MEA) in PEMFCs. In this context, we experimentally analyzed effect of flow channel depth on PEMFCs humidified with a NaCl solution at the cathode side. The analysis was conducted in serpentine flow channels with different depths of 0.4, 0.8, and 1.6 mm. The initial performance of unit cells was compared to their performance after applying a constant current for 10 hours. Results showed that the degradation rate correlated positively with the flow-channel depth. Channel depths of 0.4 and 1.6 mm resulted in 2.4% and 7.3% decreases in the maximum power density, respectively. For the 1.6 mm channel depth, the activation loss after 10 hours was larger than the initial loss.

We present a xenon arc source-based illumination system designed to achieve high spatial uniformity and efficient light collection across a wide spectral range. The proposed optical system comprised an ellipsoid reflector, diffuser, motorized iris, and collimation lens to optimize beam homogenization. Non-sequential ray-tracing simulations were performed to evaluate angular irradiation distributions of various diffusers and the overall beam profile uniformity. The system was experimentally implemented using a fused silica holographic diffuser optimized for high-power operation, with a motorized iris enabling precise control of light intensity. The resulting beam profile exhibited a well-defined flat-top shape, with a beam uniformity of approximately 95% evaluated according to the ISO 13694 standard. The developed illumination system demonstrated its ability to produce highly uniform illumination, suitable for various optical applications including spectroscopy, precision measurement, and optical imaging.