Wearable temperature sensors are becoming increasingly important for continuous health monitoring, personalized healthcare, and biointegrated electronic systems. However, conventional temperature-sensing platforms often suffer from limited thermal sensitivity, insufficient mechanical compliance, and unstable performance under repeated deformation, making it difficult to detect subtle physiological temperature variations in real time. Here, this tutorial status report presents a fabrication strategy for highly sensitive wearable temperature sensors based on gold-doped crystalline silicon nanomembranes. Gold diffusion into crystalline silicon introduces deep-level impurity states that modulate the Fermi level and shift the freeze-out region toward the physiological temperature range, enabling an ultrahigh negative temperature coefficient of resistance. By integrating the gold-doped silicon nanomembrane with a polyimide-supported ultrathin platform, neutral mechanical plane design, and serpentine mesh interconnects, the resulting device can provide high thermal sensitivity, fast response, conformal skin attachment, and stable operation under mechanical deformation. This fabrication approach is expected to broaden the use of impurity-engineered silicon nanomembranes in next-generation wearable sensors, flexible bioelectronics, and multifunctional healthcare monitoring systems.

As the importance of eco-friendly technologies increases, hydrogen vehicles are gaining significant attention as a key component of future mobility. However, the sensor technology required to accurately measure the concentration of high-purity hydrogen gas, which serves as the fuel for hydrogen vehicles, currently lacks the sensitivity needed for commercialization and remains at a demonstrative stage. This study aims to enhance the detection performance of hydrogen sensors by optimizing the fabrication process of a membrane electrode assembly (MEA) with a Pt-based electrode-electrolyte-electrode structure, where the proton-conducting electrolyte is sandwiched between upper and lower Pt electrodes. The MEA was fabricated using a hot press method, and the process was optimized by adjusting pressure, temperature, and time parameters to improve both the physical and electrical properties of the MEA. The hydrogen sensor produced using the optimized MEA showed improved sensitivity. This enhancement enables the effective monitoring of high-purity hydrogen gas used in hydrogen vehicles, thereby improving the fuel efficiency of these vehicles.

Direct exposure to toxic and hazardous gases has always been considered as the most pervasive problem worldwide, leading to a gradual increase in the number of asthma patients due to NO_x/SO_x gases inhaling and exposure to 50 ppm formaldehyde gases. Therefore, the development of accurate gas sensors is a key issue for resolving these problems. To address such issues, the development of membranes for selective filtering of target molecules as well as nanocatalyst for enhancing the sensing selectivity is highly crucial. In this review, the research progress for porous membrane materials (e.g. MOFs, and graphene) and nanocatalyst technology for the development of selective and accurate gas sensors will be discussed.

We established the emulsion method using membrane filter with precise control of LC droplet distribution in PDLC. PDLC cells with various LC droplet size distributions such as single droplet sizes of 1.0 μn, 1.9 μn and 3.5 μm, the mixture of two different LC droplet sizes and the mixture of three different LC droplet sizes were fabricated and the electro-optical properties of the emulsion type PDLC cells with various droplet size distribution were investigated. In the appropriate droplet size range, the PDLCs with the single droplet sizes distributions have good electro optical properties than those with the mixture of three different LC droplet sizes. In addition, the PDLC cells with the mixture of two different LC droplet sizes have the better electro optical properties than those with single droplet sizes distribution. The PDLC cell with dual droplet size distribution of 1.0+1.9 μm shown the best electro optical properties than the PDLC cells with other size distributions. This method enabled us to find the proper LC droplet size distribution for achieving both high transmittance and contrast ratio.

We investigated the variation of anion exchange membrane of hydrogen generator of alkaline electrolysis. We detected the variation of elements and change of anion exchange membrane using EDS and FE-SEM. We detected two different sites of membrane because of different structure of membrane. Sp2 shows that the distribution ratio of C, 0, Al is 98% very higher than Sp2 of 78%. Especially, the main elements of STS316 which is P. S. Fe, Ni were more detected at Sp2 than Sp,. We think that this result depends on the structure of membrane. This also affect the resistance, lifetime of membrane and decrease the efficiency of hydrogen production. We hope that this article is a foundation of developing of hydrogen production technology.

We fabricated the electrolyte-insulator-semiconductor (EIS) devices with various high-k sensing membranes to realize a high quality pH sensor. The sensing properties of each high-k dielectric material were compared with those of conventional SiO2 (O) and SiO2/Si3N4 (ON) membranes. As a result, the high-k sensing membranes demonstrated better sensitivity and stability than the O and ON membranes. Especially, the SiO2/HfO2 (OH) stacked layer showed a high sensitivity and the SiO2/Al2O3 (OA) stacked layer exhibited an excellent chemical stability. In conclusion, the high-k sensing membranes are expected to have excellent operating characteristics in terms of sensitivity and chemical stability for the biosensor application.