Materials such as titanium alloys, nickel alloys, and stainless steels are difficult to machine due to low thermal conductivity, work hardening, and built-up edge formation, which accelerate tool wear. Frequent tool changes are required, often relying on operator experience, leading to inefficient tool use. While modern machine tools include intelligent tool replacement systems, many legacy machines remain in service, creating a need for practical alternatives. This study proposes a method to autonomously determine tool replacement timing by monitoring machining process signals in real time, enabling automatic tool changes even on conventional machines. Tool wear is evaluated using current and vibration sensors, with the replacement threshold estimated from the maximum current observed in an initial user-defined interval. When real-time signals exceed this threshold, the system updates controller variables to trigger tool changes. Results show vibration data are more sensitive to wear, whereas current data provide greater stability. These findings indicate that a hybrid strategy combining both sensors can enhance accuracy and reliability of tool change decisions, improving machining efficiency for difficult-to-cut materials.

Intrinsically stretchable electronics enable seamless integration with dynamic biological tissues and curved surfaces, making them vital for next-generation wearables, biointerfaces, and intelligent robotics. Yet, precise, high-resolution patterning of stretchable electrodes and circuits remains challenging, limiting practical applications. Traditional lithography offers excellent resolution but is hindered by thermal and chemical incompatibilities with soft substrates. Consequently, alternative approaches such as soft lithography, laser-based patterning, printing methods, and electrospray deposition have gained importance. Soft lithography provides an economical, low-temperature option suitable for delicate materials like liquid metals. Laser-based techniques deliver high resolution and design flexibility but require careful parameter tuning for specific substrates. Mask-free printing methods, including direct ink writing and inkjet printing, enable versatile patterning of complex geometries, while electrospray deposition supports precise, non-contact patterning on stretchable surfaces. Collectively, these techniques advance the fabrication of robust stretchable displays, wireless antennas, and bioelectronic interfaces for accurate physiological monitoring. Despite progress, challenges persist, particularly in achieving large-area uniformity, multilayer stability, and sustainable processing. Addressing these issues demands interdisciplinary collaboration across materials science, fluid dynamics, interfacial engineering, and digital manufacturing. This review highlights recent progress and remaining hurdles, offering guidance for future research in stretchable electronics.

In this study, we demonstrate a synergistic enhancement of photoluminescence (PL) in an atomically thin molybdenum disulfide (MoS₂) monolayer using a dual-laser-beam-assisted chemical modification method. A continuous-wave (CW) green laser, directed perpendicularly at the MoS₂, locally raises the temperature and induces the formation of sulfur (S) vacancies, resulting in a significant increase in PL intensity. Subsequently, a UV nanosecond laser beam laterally illuminates the area above the MoS₂ layer, breaking chlorine molecules and introducing chlorine radicals without damaging the sample. This process further enhances the PL in the region previously affected by S vacancies. The binding energy of chlorine atoms to S-vacancy sites is greater than that to the pristine MoS₂ surface, facilitating more effective p-type doping. The stronger interaction at the defect sites created by the CW laser contributes to the observed synergistic PL enhancement. Our approach presents a novel method for precise and spatially selective chemical doping in two-dimensional (2D) van der Waals (vdW) materials.