The rapid growth of semiconductor and display manufacturing highlights the demand for fast, precise motion stages. Advanced systems such as lithography and bio-stages require accuracy at the μm and nm levels, but linear motor stages face challenges from disturbances, model uncertainties, and measurement noise. Disturbances and uncertainties cause deviations from models, while noise limits control gains and performance. Disturbance Observers (DOBs) enhance performance by compensating for these effects using input–output data and a nominal inverse model. However, widening the disturbance estimation bandwidth increases noise sensitivity. Conversely, the Kalman Filter (KF) estimates system states from noisy measurements, reducing noise in position feedback, but it does not treat disturbances as states, limiting compensation. To address this, we propose an Augmented Kalman Filter (AKF)–based position control for linear motor stages. The system was modeled and identified through frequency response analysis, and DOB and AKF were implemented with a PIV servo filter. Experimental validation showed reduced following error, jitter, and control effort, demonstrating the improved control performance of the AKF approach over conventional methods.

This study quantitatively examines the impact of ultraviolet (UV) intensity and energy on the formation of high aspect ratio (HAR) microstructures using the Self-Propagating Photopolymer Waveguide (SPPW) process. This mechanism relies on the self-focusing of UV light within a refractive index gradient, allowing the light to propagate and polymerize vertically beyond the initial exposure zone. Experiments were performed at UV intensities of 7.5, 12.5, and 17.5 mW/cm², with energy levels ranging from 0.0375 to 13.5 J/cm². The results indicated that a lower UV intensity of 7.5 mW/cm² produced uniform and vertically elongated structures, achieving a maximum aspect ratio of 12.26 at 0.9 J/cm². In contrast, higher UV intensities led to lateral over-curing, base expansion, and shape distortion, primarily due to rapid polymerization and the oxygen inhibition effect. These findings emphasize the importance of precisely controlling both UV intensity and energy to produce uniform, vertically aligned HAR microstructures, offering valuable insights for optimizing the SPPW process in future microfabrication applications.

A study investigated hydrogen permeability in sulfur-cured NBR composites filled with carbon black (CB) and silica, using volumetric analysis across pressures ranging from 1.2 to 92.6 MPa. Both pure NBR and MT CB- and silica-filled NBR exhibited a single sorption mechanism that followed Henry’s law, indicating hydrogen absorption into the polymer chains. In contrast, HAF CB-filled NBR displayed dual sorption behavior, adhering to both Henry’s law and the Langmuir model, which suggests additional hydrogen adsorption at the filler interface. Hydrogen diffusivity in NBR followed Knudsen diffusion at low pressures and bulk diffusion at high pressures. In HAF CB-filled NBR, permeability decreased exponentially with increasing density, while in MT CB- and silica-filled NBR, it declined linearly. The strong polymer-filler interactions in HAF CB significantly influenced permeability. Permeability trends closely correlated with hardness, tensile strength, and density, allowing for the establishment of quantitative relationships between these physical and mechanical properties. These findings indicate that analyzing these properties can predict hydrogen permeability, positioning NBR composites as promising sealing materials for high-pressure hydrogen storage in refueling stations and fuel cell vehicles.

ERCP (Endoscopic Retrograde Cholangiopancreatography) is a common procedure used to diagnose and treat biliary and pancreatic diseases. However, the repeated exposure to X-ray radiation during these procedures poses health risks to surgeons. Teleoperation systems can help reduce this exposure, but they face challenges such as the lack of force feedback and differences between the master device's mechanisms and the movements of surgical tools, which can diminish surgical precision. This study aimed to develop a master device with force feedback specifically for teleoperated ERCP guidewire insertion, drawing inspiration from the natural hand movements of surgeons. The device includes a ring-shaped translation control handle and a rotation control handle, both designed to allow unlimited movement, thereby intuitively replicating the operation of the guidewire. A force feedback system was incorporated to enable collision detection and prevent potential injuries during procedures. Experimental results showed that the proposed system enhances control precision, reduces handling inertia, and provides effective force feedback. These advancements ensure safer and more accurate guidewire manipulation, addressing key limitations of existing teleoperation systems. Ultimately, this device not only minimizes radiation exposure for surgeons but also facilitates intuitive and precise teleoperated ERCP procedures.