Ceramic thin plates are widely utilized in various advanced technologies, such as fuel cells and heat dissipation substrates, due to their high mechanical strength and thermal conductivity. However, the trend of thinning ceramic plates increases warpage, which can critically affect product quality and reliability. Therefore, understanding and accurately measuring this warpage has become increasingly important. In this study, a non-contact measurement method, the light sectioning technique, was applied to measure the warpage of thin ceramic plates with a half-cell (anode/electrolyte) structure for solid oxide fuel cells (SOFC) by varying their area and thickness. The relationship between the physical properties of the thin plates and the warpage was analyzed. Additionally, a comparative analysis was conducted to evaluate warpage errors caused by compressive loads during the traditional contact measurement process. Finally, to verify the reliability of the non-contact measurement method, four types of non-contact measurement techniques - light sectioning technique, laser displacement measurement, optical confocal technique, and white-light interferometry technique - were used to compare warpage data by orientation. The results were also compared with those from contact measurement methods to analyze the average warpage values. Through this, the superiority and high reliability of the non-contact measurement method were demonstrated.

The laser (LASER), originating from the principle of stimulated emission proposed by Albert Einstein, has been a catalyst for substantial advancements across numerous industrial and scientific domains. Initially confined to research and laboratory applications, the scope of laser technology has expanded rapidly over time. This expansion is primarily due to the laser's unique characteristics, such as high-density energy output and precise beam control, which have facilitated its widespread integration into contemporary industrial practices. Specifically, laser materials processing technology enables the machining of diverse materials, including metals, ceramics, and polymers, in a non-contact manner, thereby achieving high precision without the risk of wear or contamination. As a result, laser processing has become indispensable in fields such as advanced electronics manufacturing, medical device production, aerospace, and the automotive industry. Furthermore, laser materials processing exhibits significant potential for high-precision applications that demand minimal thermal deformation of materials, such as microfabrication and the production of complex geometries. This paper provides a comprehensive examination of the development and necessity of laser processing technology, explores various laser types and their possible applications, and elucidates why laser technology has emerged as a fundamental component of modern manufacturing, alongside its trajectory for future development.

Capacitive-type humidity sensors with a high sensitivity and fast response/recovery times have attracted a great attention in non-contact respiration biological signal monitoring applications. However, complicated fabrication processes involving high-temperature heat treatment for the hygroscopic film is essential in the conventional ceramic-based humidity sensors. In this study, a non-toxic ceramic/metal halide (BaTiO₃(BT)/NaCl) humidity sensor was prepared at room temperature using a solvent-free aerosol deposition process (AD) without any additional process. Currently prepared BT/NaCl humidity sensor shows an excellent sensitivity (245 pF/RH%) and superior response/recovery times (3s/4s) due to the NaCl ionization effect resulting in an immense interfacial polarization. Furthermore, the non-contact respiration signal variation using the BT/NaCl sensor was determined to be over 700% by maintaining the distance of 20 cm between the individual and the sensor. Through the AD-fabricated sensor in this study, we expect to develop a non-contact biological signal monitoring system that can be applied to various fields such as respiratory disease detection and management, infant respiratory signal observation, and touchless skin moisture sensing button.

Commonly, a live-line alarm can be used to measure the electric field strength of a high-voltage system to calculate its current, but it is hard to detect the electric field of shielded cables or concealed structures, such as underground distribution cables. Current sensors can detect the magnetic field in a single core wire, but they cannot determine the magnetic field about a double-core wire because the currents flow in opposite directions. Therefore, it is very difficult to detect certain current problems, such as a fault current in an extension line comprised of a double line. In this paper, to ultimately develop a sensor that can detect the current regardless of line conditions, we used a simulation to determine the concentration of the magnetic field dependent on the distribution of the external magnetic field and the path of each line’s core.