Previous Issue
Volume 16, September
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
6.0
3.0
Journals
Micromachines
Volume 16
Issue 10
share announcement

Micromachines, Volume 16, Issue 10 (October 2025) – 92 articles

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
13 pages, 1852 KB  
Article
Patterning Fidelity Enhancement and Aberration Mitigation in EUV Lithography Through Source–Mask Optimization
by Qi Wang, Qiang Wu, Ying Li, Xianhe Liu and Yanli Li
Micromachines 2025, 16(10), 1166; https://doi.org/10.3390/mi16101166 (registering DOI) - 14 Oct 2025
Abstract
Extreme ultraviolet (EUV) lithography faces critical challenges in aberration control and patterning fidelity as technology nodes shrink below 3 nm. This work demonstrates how Source–Mask Optimization (SMO) simultaneously addresses both illumination and mask design to enhance pattern transfer accuracy and mitigate aberrations. Through [...] Read more.
Extreme ultraviolet (EUV) lithography faces critical challenges in aberration control and patterning fidelity as technology nodes shrink below 3 nm. This work demonstrates how Source–Mask Optimization (SMO) simultaneously addresses both illumination and mask design to enhance pattern transfer accuracy and mitigate aberrations. Through a comprehensive optimization framework incorporating key process metrics, including critical dimension (CD), exposure latitude (EL), and mask error factor (MEF), we achieve significant improvements in imaging quality and process window for 40 nm minimum pitch patterns, representative of 2 nm node back-end-of-line (BEOL) requirements. Our analysis reveals that intelligent SMO implementation not only enables robust patterning solutions but also compensates for inherent EUV aberrations by balancing source characteristics with mask modifications. On average, our results show a 4.02% reduction in CD uniformity variation, concurrent with a 1.48% improvement in exposure latitude and a 5.45% reduction in MEF. The proposed methodology provides actionable insights for aberration-aware SMO strategies, offering a pathway to maintain lithographic performance as feature sizes continue to scale. These results underscore SMO’s indispensable role in advancing EUV lithography capabilities for next-generation semiconductor manufacturing. Full article
(This article belongs to the Special Issue Recent Advances in Lithography)
21 pages, 7655 KB  
Article
Enhancing the Machinability of Sapphire via Ion Implantation and Laser-Assisted Diamond Machining
by Jinyang Ke, Honglei Mo, Ke Ling, Jianning Chu, Xiao Chen and Jianfeng Xu
Micromachines 2025, 16(10), 1165; https://doi.org/10.3390/mi16101165 (registering DOI) - 14 Oct 2025
Abstract
Sapphire crystals, owing to their outstanding mechanical and optical properties, which are widely used in advanced optics, microelectronic devices, and medical instruments. The manufacturing precision of sapphire optical components critically affects the performance of advanced optical systems. However, the extremely high hardness and [...] Read more.
Sapphire crystals, owing to their outstanding mechanical and optical properties, which are widely used in advanced optics, microelectronic devices, and medical instruments. The manufacturing precision of sapphire optical components critically affects the performance of advanced optical systems. However, the extremely high hardness and low fracture toughness of sapphire make it a typical hard-to-machine material, prone to brittle surface fractures and subsurface damage during material removal. Improving the machinability of sapphire remains a pressing challenge in advanced manufacturing. In this study, surface modification and enhanced ductility of C-plane sapphire were achieved via ion implantation, and the machinability of the modified sapphire was further improved through laser-assisted diamond machining (LADM). Monte Carlo simulations were employed to investigate the interaction mechanisms between incident ions and the target material. Based on the simulation results, phosphorus ion implantation experiments were conducted, and transmission electron microscopy observation was used to characterize the microstructural evolution of the modified layer, while the optical properties of the samples before and after modification were analyzed. Finally, groove cutting experiments verified the enhancement in ductile machinability of the modified sapphire under LADM. At a laser power of 16 W, the ductile–brittle transition depth of the modified sapphire increased to 450.67 nm, representing a 51.57% improvement over conventional cutting. The findings of this study provide valuable insights for improving the ductile machining performance of hard and brittle materials. Full article
(This article belongs to the Special Issue Future Trends in Ultra-Precision Machining)
►▼ Show Figures

Figure 1

15 pages, 8984 KB  
Article
Sintering for High Power Optoelectronic Devices
by Hannes Schwan, Nihesh Mohan, Maximilian Schmid, Rocky Kumar Saha, Holger Klassen, Klaus Müller and Gordon Elger
Micromachines 2025, 16(10), 1164; https://doi.org/10.3390/mi16101164 - 14 Oct 2025
Abstract
Residual-free eutectic Au80Sn20 soldering is still the dominant assembly technology for optoelectronic devices such as high-power lasers, LEDs, and photodiodes. Due to the high cost of gold, alternatives are desirable. This paper investigates the thermal performance of copper-based sintering for optoelectronic submodules on [...] Read more.
Residual-free eutectic Au80Sn20 soldering is still the dominant assembly technology for optoelectronic devices such as high-power lasers, LEDs, and photodiodes. Due to the high cost of gold, alternatives are desirable. This paper investigates the thermal performance of copper-based sintering for optoelectronic submodules on first and second level to obtain thermally efficient thin bondlines. Sintered interconnects obtained by a new particle-free copper ink, based on complexed copper salt, are compared with copper flake and silver nanoparticle sintered interconnects and benchmarked against AuSn solder interconnects. The copper ink is dispensed and predried at 130 °C to facilitate in situ generation of Cu nanoparticles by thermal decomposition of the metal salt before sintering. Submounts are then sintered at 275 °C for 15 min under nitrogen with 30 MPa pressure, forming uniform 2–5 µm copper layers achieving shear strengths above 31 MPa. Unpackaged LEDs are bonded on first level using the copper ink but applying only 10 MPa to avoid damaging the semiconductor dies. Thermal performance is evaluated via transient thermal analysis. Results show that copper ink interfaces approach the performance of thin AuSn joints and match silver interconnects at second level. However, at first level, AuSn and sintered interconnects of commercial silver and copper pastes remained superior due to the relative inhomogeneous thickness of the thin Cu copper layer after predrying, requiring higher bonding pressure to equalize surface inhomogeneities. Full article
(This article belongs to the Special Issue Emerging Trends in Optoelectronic Device Engineering)
►▼ Show Figures

Figure 1

17 pages, 5096 KB  
Article
Numerical Simulation and Experimental Study on Picosecond Laser Polishing of 4H-SiC Wafer
by Yixiong Yan, Yuxuan Cheng, Sijia Chen, Yu Tang, Fan Zhang and Piaopiao Gao
Micromachines 2025, 16(10), 1163; https://doi.org/10.3390/mi16101163 - 14 Oct 2025
Abstract
4H-SiC wafers usually require polishing treatment after slicing to improve the surface quality. However, traditional polishing processes have problems such as low removal efficiency and easy surface damage, which affect the reliability of electronic devices. In this paper, picosecond laser polishing technology is [...] Read more.
4H-SiC wafers usually require polishing treatment after slicing to improve the surface quality. However, traditional polishing processes have problems such as low removal efficiency and easy surface damage, which affect the reliability of electronic devices. In this paper, picosecond laser polishing technology is used to study the 4H-SiC wafers after slicing. Numerical models of single-pulse ablation and moving heat source polishing were established to reveal the interaction mechanism between laser and material, including the dynamic evolution of free electron density and the remarkable spatiotemporal non-equilibrium heat transfer characteristics of the electron–lattice system. The sliced 4H-SiC surface with a roughness of 2265 nm was polished by a 1064 nm picosecond laser, and the influence of laser power and scanning speed on the surface quality was systematically studied. By collaboratively optimizing the polishing power and speed, the surface roughness of the sample can be significantly reduced to 207.33 nm (a decrease of 90.85%). The research results indicate that an ultrafast laser is suitable for the pretreatment process of sliced silicon carbide wafers, laying a foundation for further research in the future. This research has a certain research significance for promoting the development of ultrafast laser polishing technology for single crystal silicon carbide wafers and improving the performance and reliability of semiconductor devices. Full article
►▼ Show Figures

Figure 1

23 pages, 2493 KB  
Article
EAAUnet-ILT: A Lightweight and Iterative Mask Optimization Resolution with SRAF Constraint Scheme
by Ke Wang and Kun Ren
Micromachines 2025, 16(10), 1162; https://doi.org/10.3390/mi16101162 - 14 Oct 2025
Abstract
With the continuous scaling-down of integrated circuit feature sizes, inverse lithography technology (ILT), as the most groundbreaking resolution enhancement technique (RET), has become crucial in advanced semiconductor manufacturing. By directly optimizing mask patterns through inverse computation rather than rule-based local corrections, ILT can [...] Read more.
With the continuous scaling-down of integrated circuit feature sizes, inverse lithography technology (ILT), as the most groundbreaking resolution enhancement technique (RET), has become crucial in advanced semiconductor manufacturing. By directly optimizing mask patterns through inverse computation rather than rule-based local corrections, ILT can more accurately approximate target design patterns while extending the process window. However, current mainstream ILT approaches—whether machine learning-based or gradient descent-based—all face the challenge of balancing mask optimization quality and computational time. Moreover, ILT often faces a trade-off between imaging fidelity and manufacturability; fidelity-prioritized optimization leads to explosive growth in mask complexity, whereas manufacturability constraints require compromising fidelity. To address these challenges, we propose an iterative deep learning-based ILT framework incorporating a lightweight model, ghost and adaptive attention U-net (EAAUnet) to accelerate runtime and reduce computational overhead while progressively improving mask quality through multiple iterations based on the pre-trained network model. Compared to recent state-of-the-art (SOTA) ILT solutions, our approach achieves up to a 39% improvement in mask quality metrics. Additionally, we introduce a mask constraint scheme to regulate complex SRAF (sub-resolution assist feature) patterns on the mask, effectively reducing manufacturing complexity. Full article
(This article belongs to the Special Issue Recent Advances in Lithography)
►▼ Show Figures

Figure 1

3 pages, 705 KB  
Correction
Correction: Wang et al. Temperature Effects in Packaged RF MEMS Switches with Optimized Gold Electroplating Process. Micromachines 2024, 15, 1085
by Lifeng Wang, Lili Jiang, Ning Ma and Xiaodong Huang
Micromachines 2025, 16(10), 1161; https://doi.org/10.3390/mi16101161 - 14 Oct 2025
Abstract
It was found that the temperature control of the electroplating station in the previously published paper [...] Full article
►▼ Show Figures

Figure 2

17 pages, 3651 KB  
Article
Optofluidic Lens Refractometer
by Yifan Zhang, Qi Wang, Yuxiang Li, Junjie Liu, Ziyue Lin, Mingkai Fan, Yichi Zhang and Xiang Wu
Micromachines 2025, 16(10), 1160; https://doi.org/10.3390/mi16101160 - 13 Oct 2025
Abstract
In the face of increasingly severe global environmental challenges, the development of low-cost, high-precision, and easily integrable environmental monitoring sensors is of paramount importance. Existing optical refractive index sensors are often limited in application due to their complex structures and high costs, or [...] Read more.
In the face of increasingly severe global environmental challenges, the development of low-cost, high-precision, and easily integrable environmental monitoring sensors is of paramount importance. Existing optical refractive index sensors are often limited in application due to their complex structures and high costs, or their bulky size and difficulty in automation. This paper proposes a novel optical microfluidic refractometer, consisting solely of a laser source, an optical microfluidic lens, and a CCD detector. Through an innovative “simple structure + algorithm” design, the sensor achieves high-precision measurement while significantly reducing cost and size and enhancing robustness. With the aid of signal processing algorithms, the device currently enables the detection of refractive index gradients as low as 1.4 × 10−5 within a refractive index range of 1.33 to 1.48. Full article
(This article belongs to the Special Issue Optofluidic Devices and Their Applications)
►▼ Show Figures

Figure 1

15 pages, 1187 KB  
Review
Integration of Point-of-Care Technology in the Decoding Process of Single Nucleotide Polymorphism for Healthcare Application †
by Thi Ngoc Diep Trinh, Hanh An Nguyen, Nguyen Pham Anh Thi, Thi Xuan Tuy Ho, Kieu The Loan Trinh and Nguyen Khoi Song Tran
Micromachines 2025, 16(10), 1159; https://doi.org/10.3390/mi16101159 - 13 Oct 2025
Abstract
Single nucleotide polymorphism (SNP) involves plenty of genetic disorders in organisms that can be passed down to the next generation or cause the stimulant signal that leads to early mortality in infants, especially within humankind. In medical field, real-time polymerase chain reaction (RT-PCR) [...] Read more.
Single nucleotide polymorphism (SNP) involves plenty of genetic disorders in organisms that can be passed down to the next generation or cause the stimulant signal that leads to early mortality in infants, especially within humankind. In medical field, real-time polymerase chain reaction (RT-PCR) is the most popular method for disease diagnosis. The investigation of genetic maps for the prediction of inherited illnesses needs the collaboration of sequencing technique and genome analysis. Although these methods are popular now, the cost for each test is quite high. Moreover, there is the requirement of extra machines and skillful technician or specialist level. Among these popular methods, the allele-specific polymerase chain reaction (AS-PCR), allele-specific loop isothermal mediated amplification (AS-LAMP), and allele-specific recombinase polymerase amplification (AS-RPA) are brought up for screening the nucleotide differences in the genetic sequence which will be noticed in this review as their availability, novelty, and potential for quick distinguishing of disease caused by SNP. Point-of-care testing (POCT) is a system built in a portable size but can perform the entire process of SNP recognition. Along with that, the POCT is intersected with the mentioned amplification methods and the genetic material preparation steps to become a united framework for higher efficiency and accuracy and lower cost. According to that, this review will focus on three common amplification techniques and their combination with POCT in the upstream and downstream process to genotype SNP related to human diseases. Full article
(This article belongs to the Section B4: Point-of-Care Devices)
►▼ Show Figures

Figure 1

34 pages, 4932 KB  
Review
Recent Progress in Liquid Microlenses and Their Arrays for Adaptive and Applied Optical Systems
by Siyu Lu, Zheyuan Cao, Jinzhong Ling, Ying Yuan, Xin Liu, Xiaorui Wang and Jin-Kun Guo
Micromachines 2025, 16(10), 1158; https://doi.org/10.3390/mi16101158 - 13 Oct 2025
Abstract
Liquid microlenses and their arrays (LMLAs) have emerged as a transformative platform in adaptive optics, offering superior reconfigurability, compactness, and fast response compared to conventional solid-state lenses. This review summarizes recent progress from an application-oriented perspective, focusing on actuation mechanisms, fabrication strategies, and [...] Read more.
Liquid microlenses and their arrays (LMLAs) have emerged as a transformative platform in adaptive optics, offering superior reconfigurability, compactness, and fast response compared to conventional solid-state lenses. This review summarizes recent progress from an application-oriented perspective, focusing on actuation mechanisms, fabrication strategies, and functional performance. Among actuation mechanisms, electric-field-driven approaches are highlighted, including electrowetting for shape tuning and liquid crystal-based refractive-index tuning techniques. The former excels in tuning range and response speed, whereas the latter enables programmable wavefront control with lower optical aberrations but limited efficiency. Notably, double-emulsion configurations, with fast interfacial actuation and inherent structural stability, demonstrate great potential for highly integrated optical components. Fabrication methodologies—including semiconductor-derived processes, additive manufacturing, and dynamic molding—are evaluated, revealing trade-offs among scalability, structural complexity, and cost. Functionally, advances in focal length tuning, field-of-view expansion, depth-of-field extension, and aberration correction have been achieved, though strong coupling among these parameters still constrains system-level performance. Looking forward, innovations in functional materials, hybrid fabrication, and computational imaging are expected to mitigate these constraints. These developments will accelerate applications in microscopy, endoscopy, AR/VR displays, industrial inspection, and machine vision, while paving the way for intelligent photonic systems that integrate adaptive optics with machine learning for real-time control. Full article
(This article belongs to the Special Issue Micro-Nano Photonics: From Design and Fabrication to Application)
►▼ Show Figures

Figure 1

12 pages, 1654 KB  
Article
Research on Open Magnetic Shielding Packaging for STT and SOT-MRAM
by Haibo Ye, Xiaofei Zhang, Nannan Lu, Jiawei Li, Jun Jia, Guilin Zhao, Jiejie Sun, Lei Zhang and Chao Wang
Micromachines 2025, 16(10), 1157; https://doi.org/10.3390/mi16101157 - 13 Oct 2025
Abstract
As an emerging type of non-volatile memory, magneto-resistive random access memory (MRAM) stands out for its exceptional reliability and rapid read–write speeds, thereby garnering considerable attention within the industry. The memory cell architecture of MRAM is centered around the magnetic tunnel junction (MTJ), [...] Read more.
As an emerging type of non-volatile memory, magneto-resistive random access memory (MRAM) stands out for its exceptional reliability and rapid read–write speeds, thereby garnering considerable attention within the industry. The memory cell architecture of MRAM is centered around the magnetic tunnel junction (MTJ), which, however, is prone to interference from external magnetic fields—a limitation that restricts its application in demanding environments. To address this challenge, we propose an innovative open magnetic shielding structure. This design demonstrates remarkable shielding efficacy against both in-plane and perpendicular magnetic fields, effectively catering to the magnetic shielding demands of both spin-transfer torque (STT) and spin–orbit torque (SOT) MRAM. Finite element magnetic simulations reveal that when subjected to an in-plane magnetic field of 40 mT, the magnetic field intensity at the chip level is reduced to nearly 1‰ of its original value. Similarly, under a perpendicular magnetic field of 40 mT, the magnetic field at the chip is reduced to 2‰ of its initial strength. Such reductions significantly enhance the anti-magnetic capabilities of MRAM. Moreover, the magnetic shielding performance remains unaffected by the height of the packaging structure, ensuring compatibility with various chip stack packaging requirements across different layers. The research presented in this paper holds immense significance for the realization of highly reliable magnetic shielding packaging solutions for MRAM. Full article
►▼ Show Figures

Figure 1

17 pages, 3320 KB  
Article
Research on Optimizing Forming Accuracy in Food 3D Printing Based on Temperature–Pressure Dual Closed-Loop Control
by Junhua Wang, Hao Cao, Jianan Shen, Xu Duan, Yanwei Xu, Tancheng Xie and Ruijie Gu
Micromachines 2025, 16(10), 1156; https://doi.org/10.3390/mi16101156 - 12 Oct 2025
Viewed by 44
Abstract
In this paper, a new 3D printing system based on temperature–pressure double closed-loop collaborative control is proposed to solve the problem of 3D printing accuracy of starch food. The rapid and accurate adjustment of the nozzle temperature is realized by the hybrid control [...] Read more.
In this paper, a new 3D printing system based on temperature–pressure double closed-loop collaborative control is proposed to solve the problem of 3D printing accuracy of starch food. The rapid and accurate adjustment of the nozzle temperature is realized by the hybrid control of Bang-Bang and PID, and the extrusion pressure is optimized in real time by combining the adaptive fuzzy PID algorithm, which effectively reduces the influence from the change of material rheological properties and external interference. The experimental results show that the printing accuracy of the system is up to 98% at 40 °C, the pressure fluctuation is reduced by 80%, and the molding accuracy of complex structures is improved to 97%, which significantly improves the over-extrusion and under-extrusion, and provides an effective solution for stable and high-precision printing of high-viscosity food materials. Full article
(This article belongs to the Special Issue Advanced Micro- and Nano-Manufacturing Technologies, 2nd Edition)
►▼ Show Figures

Figure 1

15 pages, 5525 KB  
Article
Post Wire-Bonding Corrosion Prevention Strategies to Mitigate Chloride- and Bromide-Induced Corrosion Failures in Cu- and PCC-Based Wire-Bonded Packages
by Dinesh Kumar Kumaravel, Shinoj Sridharan Nair, Khanh Tuyet Anh Tran, Pavan Ahluwalia, Kevin Antony Jesu Durai and Oliver Chyan
Micromachines 2025, 16(10), 1155; https://doi.org/10.3390/mi16101155 - 12 Oct 2025
Viewed by 43
Abstract
To ensure the highest safety standards in modern automobiles, the industry is constantly adopting zero-defect frameworks, such as AEC-Q100, which aims for defective-parts-per-billion (DPPB) or grade-0 level reliability standards in automotive integrated-circuit (IC) packages. Most contemporary wire-bonded packages use either pure copper (Cu) [...] Read more.
To ensure the highest safety standards in modern automobiles, the industry is constantly adopting zero-defect frameworks, such as AEC-Q100, which aims for defective-parts-per-billion (DPPB) or grade-0 level reliability standards in automotive integrated-circuit (IC) packages. Most contemporary wire-bonded packages use either pure copper (Cu) or palladium (Pd)-coated copper (PCC) wires bonded to aluminum (Al) bond pads as interconnections. This choice is made due to their lower cost and superior electrical and mechanical performance, compared to traditional gold wire-based devices. However, these Cu–Al wire-bonded interconnections are prone to ion-induced lift-off/open-circuit corrosion failures when exposed to even trace amounts (<20 ppm) of extrinsic and/or intrinsic halide (Cl− and Br−) contaminants, decreasing device longevity. This study investigates corrosion failure mechanisms in Cu and PCC wire-based devices by subjecting non-encapsulated devices to a highly accelerated aqueous-immersion screening test containing 100 ppm chloride (Cl−), 100 ppm bromide (Br−), and a mixed-ion solution (MX: Cl− + Br−). The screening results indicate that even control PCC-Al devices with a Pd overlayer can be susceptible to Cl− and Br− induced corrosion, with 21 ± 1.6% lift-off failures in MX-solution. In contrast, applying a novel Cu-selective passivation reduced lift-off to 3.3 ± 0.6% and introducing phosphonic-acid-based inhibitor into the MX solution eliminated lift-off failures, demonstrating markedly improved reliability. Full article
(This article belongs to the Special Issue Microelectronics Assembly and Packaging: Materials and Technologies, 2nd Edition)
►▼ Show Figures

Figure 1

14 pages, 6040 KB  
Article
Analysis of Key Factors Affecting the Sensitivity of Dual-Backplate Capacitive MEMS Microphones
by Chengpu Sun, Haosheng Liu, Ludi Kang and Bilong Liu
Micromachines 2025, 16(10), 1154; https://doi.org/10.3390/mi16101154 - 12 Oct 2025
Viewed by 38
Abstract
This paper presents a comprehensive investigation of sensitivity-determining factors in dual-backplate capacitive MEMS microphones through analytical modeling, finite element analysis (FEM), and experimental validation. The study focuses on three critical design parameters: backplate perforation density, membrane tension, and electrode gap spacing. A lumped [...] Read more.
This paper presents a comprehensive investigation of sensitivity-determining factors in dual-backplate capacitive MEMS microphones through analytical modeling, finite element analysis (FEM), and experimental validation. The study focuses on three critical design parameters: backplate perforation density, membrane tension, and electrode gap spacing. A lumped parameter model (LPM) and FEM simulations are employed to characterize the dynamic behavior and frequency response of the microphone. Simulation results demonstrate that reducing the backplate hole diameter or hole count amplifies squeeze-film damping, inducing nonlinear effects and anti-resonance dips near the fundamental frequency (f0) while mitigating low-frequency roll-off (<100 Hz). Membrane tension exhibits a nonlinear relationship with sensitivity, stabilizing at high tension (>7000 N/m) but risking pull-in instability at low tension (<1500 N/m). Smaller electrode gaps enhance sensitivity but are constrained by pull-in voltage limitations. The FEM model achieves higher accuracy (≤2 dB error) than LPM in predicting low-frequency response anomalies. This work provides systematic guidelines for optimizing dual-backplate MEMS microphone designs, balancing sensitivity, stability, and manufacturability. Full article
►▼ Show Figures

Figure 1

13 pages, 5799 KB  
Article
Additive Manufacturing of Gear Electrodes and EDM of a Gear Cavity
by Kai Jiang, Yangquan Liu, Bin Xu, Shunda Zhan and Junwei Liang
Micromachines 2025, 16(10), 1153; https://doi.org/10.3390/mi16101153 - 11 Oct 2025
Viewed by 84
Abstract
Plastic gears are used in a variety of industrial fields and are primarily produced by injection molding with a gear cavity. At present, EDM is usually used for machining gear cavities with metal materials, and the tool electrode used in the process is [...] Read more.
Plastic gears are used in a variety of industrial fields and are primarily produced by injection molding with a gear cavity. At present, EDM is usually used for machining gear cavities with metal materials, and the tool electrode used in the process is usually machined through a milling process. For helical gear cavities and helical bevel gear cavities, certain problems are encountered when the tool electrodes of EDM are obtained from milling procedures, including waste of raw materials and the complex technical process. Focusing on the above problems, this paper used copper powder to fabricate gear electrodes through a selective laser sintering process. The obtained gear electrodes underwent heat treatment and the effects of the main process parameters on the electrical conductance of tool electrodes were analyzed in this study. Finally, the heat-treated gear electrodes were applied to EDM to fabricate a helical gear cavity and a helical bevel gear cavity. During EDM, the TWR and MRR of the gear electrodes were 0.0029 mm3/min and 0.3872 mm3/min, respectively. Compared with that of gear electrodes made by the milling process, the MRR of the gear electrodes fabricated by SLS improved by 31.53%. Full article
(This article belongs to the Special Issue Micro-Manufacturing and Applications, 5th Edition: Materials and High-Precision Micromachining)
►▼ Show Figures

Figure 1

33 pages, 3122 KB  
Review
Thermal Side-Channel Threats in Densely Integrated Microarchitectures: A Comprehensive Review for Cyber–Physical System Security
by Amrou Zyad Benelhaouare, Idir Mellal, Michel Saydé, Gabriela Nicolescu and Ahmed Lakhssassi
Micromachines 2025, 16(10), 1152; https://doi.org/10.3390/mi16101152 - 11 Oct 2025
Viewed by 291
Abstract
Densely integrated microarchitectures spanning three-dimensional integrated circuits (3D-ICs), chiplet-based designs, and system-in-package (SiP) assemblies make heat a first-order security concern rather than a mere reliability issue. This review consolidates the landscape of thermal side-channel attacks (TSCAs) on densely integrated microarchitectures: we systematize observation [...] Read more.
Densely integrated microarchitectures spanning three-dimensional integrated circuits (3D-ICs), chiplet-based designs, and system-in-package (SiP) assemblies make heat a first-order security concern rather than a mere reliability issue. This review consolidates the landscape of thermal side-channel attacks (TSCAs) on densely integrated microarchitectures: we systematize observation vectors and threat models, clarify core concepts and assumptions, compare the most credible evidence from the past decade, and distill the main classes of defenses across the hardware–software stack. We also explain why hardening against thermal leakage is integral to cyber–physical system (CPS) security and outline the most promising research directions for the field. The strategic relevance of this agenda is reflected in current policy and funding momentum, including initiatives by the United States Department of Homeland Security and the Cybersecurity and Infrastructure Security Agency (DHS/CISA) on operational technology (OT) security, programs by the National Science Foundation (NSF) on CPS, and Canada’s Regional Artificial Intelligence Initiative and Cyber-Physical Resilience Program (RAII, >CAD 35 million), to bridge advanced microelectronics with next-generation cybersecurity. This survey offers a clear, high-level map of the problem space and a focused baseline for future work. Full article
(This article belongs to the Special Issue Microelectronics Assembly and Packaging: Materials and Technologies, 2nd Edition)
►▼ Show Figures

Figure 1

14 pages, 4357 KB  
Article
Thermal Gas Flow Sensor Using SiGe HBT Oscillators Based on GaN/Si SAW Resonators
by Wenpu Cui, Jie Cui, Wenchao Zhang, Guofang Yu, Di Zhao, Jingqing Du, Zhen Li, Jun Fu and Tianling Ren
Micromachines 2025, 16(10), 1151; https://doi.org/10.3390/mi16101151 - 10 Oct 2025
Viewed by 116
Abstract
This paper presents a thermal gas flow sensing system, from surface acoustic wave (SAW) temperature sensor to oscillation circuit and multi-module miniaturization integration. A single-port GaN/Si SAW resonator with single resonant mode and excellent characteristics was fabricated. Combined with an in-house-developed SiGe HBT, [...] Read more.
This paper presents a thermal gas flow sensing system, from surface acoustic wave (SAW) temperature sensor to oscillation circuit and multi-module miniaturization integration. A single-port GaN/Si SAW resonator with single resonant mode and excellent characteristics was fabricated. Combined with an in-house-developed SiGe HBT, a temperature-sensitive high-frequency oscillator was constructed. Under constant temperature control, system-level flow measurement was achieved through dual-oscillation configuration and modular integration. The fabricated SAW device shows a temperature coefficient of frequency (TCF) −28.29 ppm/K and temperature linearity 0.998. The oscillator operates at 1.91 GHz with phase noise of −97.72/−118.62 dBc/Hz at 10/100 kHz offsets. The system demonstrates excellent dynamic response and repeatability, directly measuring 0–50 sccm flows. For higher flows (>50 sccm), a shunt technique extends the test range based on the 0–10 sccm linear region, where response time is <1 s with error <0.9%. Non-contact operation ensures high stability and long lifespan. The sensor shows outstanding performance and broad application prospects in flow measurement. Full article
►▼ Show Figures

Figure 1

17 pages, 6132 KB  
Article
Nanostructured Scaffold, Combined with Human Dental Pulp Stem Cell Secretome, Induces Vascularization in Medicinal Leech Model
by Gaia Marcolli, Nicolò Baranzini, Ludovica Barone, Federica Rossi, Laura Pulze, Christina Pagiatakis, Roberto Papait, Annalisa Grimaldi and Rosalba Gornati
Micromachines 2025, 16(10), 1150; https://doi.org/10.3390/mi16101150 - 10 Oct 2025
Viewed by 111
Abstract
As life expectancy continues to increase, age-related disorders are becoming more prevalent. Among these, vascular complications resulting from chronic inflammation are particularly concerning, as they impair angiogenesis and hinder tissue repair, both processes that heavily rely on a well-structured extracellular matrix (ECM). In [...] Read more.
As life expectancy continues to increase, age-related disorders are becoming more prevalent. Among these, vascular complications resulting from chronic inflammation are particularly concerning, as they impair angiogenesis and hinder tissue repair, both processes that heavily rely on a well-structured extracellular matrix (ECM). In this context, MicroMatrix® UBM Particulate, a skin substitute composed of collagen, laminin, and proteoglycans, appears to offer properties conducive to tissue regeneration. The aim of this study was to evaluate the regenerative potential of MicroMatrix® combined with the Secretome of human Dental Pulp Stem Cells (hDPSC-S), using the medicinal leech Hirudo verbana, a well-established model for studying wound healing, angiogenesis, and tissue regeneration. Adult leeches were injected with MicroMatrix® either suspended in FBS-free medium (CTRL) or supplemented with hDPSC-S. 1-week post-treatment, the animals were sacrificed and subjected to morphological and immunohistochemical analyses. Our findings revealed that MicroMatrix® successfully integrated into the leech body wall. Notably, when supplemented with hDPSC-S, there was a marked increase in cell infiltration, including telocytes and Hematopoietic Precursor Stem Cells, along with a significantly higher vessel density compared to CTRL. These results support the effectiveness of the cell-free device composed of MicroMatrix® and hDPSC-S, highlighting its potential as a promising strategy for regenerative therapies aimed at treating complex wounds with poor vascularization. Full article
►▼ Show Figures

Figure 1

11 pages, 5294 KB  
Article
A Mini-Two-Path Mach–Zehnder Interferometer Sensor with High Curvature Sensitivity Based on Four-Mode Fiber
by Wuming Wu, Jiayi Qian, Yuechun Shi and Xiaojun Zhu
Micromachines 2025, 16(10), 1149; https://doi.org/10.3390/mi16101149 - 10 Oct 2025
Viewed by 175
Abstract
We have proposed and presented a hybrid mini-two-path Mach–Zehnder interferometer (MTP-MZI) sensor based on four-mode fiber (FMF), where the reference path comprises of a section of a single-mode fiber (SMF), and the sensing path adopts a structure of SMF-FMF-SMF (SFS). Using arc discharge [...] Read more.
We have proposed and presented a hybrid mini-two-path Mach–Zehnder interferometer (MTP-MZI) sensor based on four-mode fiber (FMF), where the reference path comprises of a section of a single-mode fiber (SMF), and the sensing path adopts a structure of SMF-FMF-SMF (SFS). Using arc discharge technology, the two paths are effectively fused and coupled, resulting in a robust MTP-MZI structure sensor. In the curvature detection, the maximum intensity sensitivity of curvature reaches 168.41 dB/m−1 when the curvature ranges change from 0 m−1 to 0.091 m−1. To the best of our knowledge, it is the highest curvature sensitivity in the MZI fiber sensor with intensity modulation. Furthermore, we also conducted a temperature-sensing experiment. The experiment results show that the maximum temperature sensitivity is only 78 pm/°C with a temperature range of 30–65 °C. The diverse exhibition of sensing performance for curvature and temperature enables us to effectively mitigate cross-sensitivity challenges. These results provide the experimental basis for developing a high-sensitivity sensor by employing the mini-two-path structure combined with specialty fibers. Full article
(This article belongs to the Special Issue High-Sensitivity Fiber-Optic Sensors: From Design to Applications)
►▼ Show Figures

Figure 1

19 pages, 1885 KB  
Article
Theoretical Model for a Pneumatic Nozzle–Cylindrical Flapper System
by Peimin Xu, Kazuaki Inaba and Toshiharu Kagawa
Micromachines 2025, 16(10), 1148; https://doi.org/10.3390/mi16101148 - 10 Oct 2025
Viewed by 168
Abstract
To increase semiconductor production yield and meet the growing global demand, air bearings offering higher processing speeds and reduced friction losses have been proposed as an ideal solution. However, due to the non-contact support characteristic of air bearings, challenges such as shaft displacement [...] Read more.
To increase semiconductor production yield and meet the growing global demand, air bearings offering higher processing speeds and reduced friction losses have been proposed as an ideal solution. However, due to the non-contact support characteristic of air bearings, challenges such as shaft displacement caused by processing resistance inevitably arise. As an engineering requirement, the shaft must restrict lateral deflection to within 30 μm under transverse force. In our previous research, a compensation system using a nozzle–flapper mechanism as a displacement sensor was proposed to address shaft displacement. The effectiveness of the nozzle–flapper system in measuring shaft displacement was validated at rotational speeds up to 20,000 rpm. Furthermore, the compensation system’s ability to maintain the shaft’s initial position under a 5 N external force was verified in related collaborative research. In this study, building upon prior work, we further analyze the system characteristics of the cylindrical nozzle–flapper. This includes modeling the geometric space formed by the specific shape of the cylindrical flapper and nozzle and proposing an airflow hypothesis based on this geometry. The hypothesis is incorporated into the theoretical model of a standard nozzle–flapper system, resulting in an optimized theoretical method applicable to cylindrical configurations. Experimental results validating the effectiveness of the proposed model are also presented. Full article
(This article belongs to the Special Issue Flexible and Biodegradable Electronics and Novel Semiconductor Devices)
►▼ Show Figures

Figure 1

12 pages, 1430 KB  
Article
Influence of LPCVD-Si3N4 Thickness on Polarization Coulomb Field Scattering in AlGaN/GaN Metal–Insulator–Semiconductor High-Electron-Mobility Transistors
by Guangyuan Jiang, Weikang Li, Xin Luo, Yang Liu, Chen Fu, Qingying Zhang, Guangyuan Zhang, Zhaojun Lin and Peng Cui
Micromachines 2025, 16(10), 1147; https://doi.org/10.3390/mi16101147 - 10 Oct 2025
Viewed by 171
Abstract
The thickness of the LPCVD-Si3N4 gate dielectric layer significantly influences the electron transport properties of AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs), but the mechanism by which it affects polarization Coulomb field (PCF) scattering remains largely unexplored. In this study, AlGaN/GaN MIS-HEMTs [...] Read more.
The thickness of the LPCVD-Si3N4 gate dielectric layer significantly influences the electron transport properties of AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs), but the mechanism by which it affects polarization Coulomb field (PCF) scattering remains largely unexplored. In this study, AlGaN/GaN MIS-HEMTs with LPCVD-Si3N4 gate dielectric thicknesses of 0 nm, 5 nm, and 20 nm were fabricated, and the influence of LPCVD-Si3N4 thickness on PCF scattering was systematically investigated. Through electrical measurements and theoretical calculations, the relationship between LPCVD-Si3N4 gate dielectric layer thickness, additional polarization charge (∆ρ), two-dimensional electron gas (2DEG) density, and 2DEG mobility was analyzed. The results show that increasing the LPCVD-Si3N4 thickness reduces the vertical electric field in the AlGaN barrier, weakening the inverse piezoelectric effect (IPE) and reducing ∆ρ. Further analysis reveals that the ∆ρ exhibits a non-monotonic dependence on negative gate voltage, initially increasing and subsequently decreasing, due to the competition between strain accumulation and stress relaxation. Meanwhile, the 2DEG mobility limited by PCF (μPCF) decreases monotonically with increasing negative gate voltage, mainly due to the progressive weakening of the 2DEG screening effect. The research results reveal the physical mechanism by which LPCVD-Si3N4 thickness regulates PCF scattering, providing theoretical guidance for optimizing gate dielectric parameters and enhancing the performance of AlGaN/GaN MIS-HEMTs. Full article
(This article belongs to the Section D1: Semiconductor Devices)
►▼ Show Figures

Figure 1

14 pages, 4599 KB  
Article
A Numerical and Experimental Study on the Enrichment Performance of a Novel Multi-Physics Coupling Microchannel
by Qiao Liu, Ruiju Shi and Tongxu Gu
Micromachines 2025, 16(10), 1146; https://doi.org/10.3390/mi16101146 - 10 Oct 2025
Viewed by 175
Abstract
The coupled method of inertial focusing and magnetic separation is effective for detecting and isolating circulating tumor cells (CTCs) from blood, wherein the design of a multi-physics coupled microfluidic device plays a critical role in the sorting efficiency. This paper presents a novel [...] Read more.
The coupled method of inertial focusing and magnetic separation is effective for detecting and isolating circulating tumor cells (CTCs) from blood, wherein the design of a multi-physics coupled microfluidic device plays a critical role in the sorting efficiency. This paper presents a novel compact microfluidic device that combines inertial and magnetic forces for CTC separation. Using the finite element method, the effects of three major parameters (e.g., fluid velocity, particle properties, and magnetic field distribution) on sorting efficiency were comprehensively investigated and discussed. Simulated and experimental results demonstrate that the designed compact microfluidic device with coupled physical fields achieves high separation purity (>98%) for CTCs larger than 19 μm in diameter over a wide range of parameters, such as a fluid velocity greater than 3.5 × 10−8 m3/s, a remanent flux density between 1.08 T and 1.28 T, and the position of the magnet ranging from 2.5 mm to 4 mm. Full article
(This article belongs to the Special Issue Recent Progress of Lab-on-a-Chip Assays)
►▼ Show Figures

Figure 1

11 pages, 1394 KB  
Article
Numerical and Experimental Analysis of Microparticle Focusing and Separation in Split–Recombination Microchannel
by Shuang Chen, Jiajia Sun, Zongqian Shi, Lijie Sun and Junxiong Guo
Micromachines 2025, 16(10), 1145; https://doi.org/10.3390/mi16101145 - 10 Oct 2025
Viewed by 261
Abstract
Inertial microfluidics has obtained attention for its good performance in microparticle manipulation. It has the advantages of simplicity, high throughput, and a lack of external fields. In this paper, a simple microfluidic device is described, which contains several split and recombination structures. The [...] Read more.
Inertial microfluidics has obtained attention for its good performance in microparticle manipulation. It has the advantages of simplicity, high throughput, and a lack of external fields. In this paper, a simple microfluidic device is described, which contains several split and recombination structures. The design takes advantage of microparticle migration based on inertial lift and the Dean drag force. Two forces drive microparticles to move laterally and arrive at equilibrium positions in a split–recombination microchannel. Based on the numerical and experimental analysis, the trajectories of microparticles are described, and microparticles are focused and form two narrow streams. In addition, the focusing of microparticles is enhanced significantly with the increase in angle. Finally, two sizes of microparticles are separated in experiments. The simple device and high throughput offered by this passive microfluidic approach make it attractive in biomedical and environmental applications. Full article
(This article belongs to the Special Issue Flows in Micro- and Nano-Systems)
►▼ Show Figures

Figure 1

32 pages, 4265 KB  
Review
A Review on Biomedical, Biomolecular, and Environmental Monitoring Applications of Cysteamine Functionalized Nanomaterials
by Muthaiah Shellaiah
Micromachines 2025, 16(10), 1144; https://doi.org/10.3390/mi16101144 - 8 Oct 2025
Viewed by 366
Abstract
Functionalizing agents enhance the photophysical properties of nanomaterials, thereby broadening their applications. Among these agents, cysteamine (SH-(CH2)2-NH2) is unique because of its free thiol (-SH) and amino (-NH2) groups. The presence of free -SH or [...] Read more.
Functionalizing agents enhance the photophysical properties of nanomaterials, thereby broadening their applications. Among these agents, cysteamine (SH-(CH2)2-NH2) is unique because of its free thiol (-SH) and amino (-NH2) groups. The presence of free -SH or -NH2 groups significantly enhances the functionalization of highly stable nanomaterials. These stable nanomaterials, which contain free -SH or -NH2 groups, can effectively bind with biomedical, biomolecular, and environmental analytes, improving sensor performance and making them valuable materials. In this context, cysteamine-functionalized nanoparticles (NPs), quantum dots (QDs), nanoclusters (NCs), nanocomposites, and other nanostructures have been demonstrated to be useful for quantifying biomedical, biomolecular, and environmental analytes. To date, no review has outlined the functionalizing ability of cysteamine or the application of cysteamine-functionalized nanomaterials in biomedical, biomolecular, and environmental analyte monitoring. This review emphasizes the role of cysteamine in producing stable nanomaterials and detecting specific biomedical, biomolecular, and ecological analytes. It also covers general protocols for functionalizing with cysteamine, the mechanistic basis of analyte detection, and their advantages, limitations, and prospects. Full article
(This article belongs to the Special Issue Nanoparticle-Based (Bio)Sensors for Biomedical and Environmental Monitoring)
►▼ Show Figures

Figure 1

17 pages, 2890 KB  
Article
Machining Micro-Error Compensation Methods for External Turning Tool Wear of CNC Machines
by Hui Zhang, Tongwei Lu, Zhijie Xia, Zhisheng Zhang and Jianxiong Zhu
Micromachines 2025, 16(10), 1143; https://doi.org/10.3390/mi16101143 - 8 Oct 2025
Viewed by 249
Abstract
Tool wear detection is very important in CNC machine tool cutting. Once the tool is excessively worn, it is not only easy to cause the workpiece to be scrapped, but even to damage the machine. Therefore, common external turning tools of CNC machines [...] Read more.
Tool wear detection is very important in CNC machine tool cutting. Once the tool is excessively worn, it is not only easy to cause the workpiece to be scrapped, but even to damage the machine. Therefore, common external turning tools of CNC machines are studied. The effect of tool nose wear on machining accuracy was analyzed by a building mathematical model. According to different wear conditions, a linear detection method based on edge images and input features was proposed to detect the main and secondary cutting edges, which helped determine the theoretical center of the tool nose and build a morphological visual model. For different error cases, the axial and radial error compensation strategies were proposed, respectively. By comparing the experimental data of four kinds of workpieces before and after compensation machining, the average errors of them were reduced separately, and the maximum value reached 79.2%, which verified the effectiveness of the compensation strategy. The intelligent compensation strategies will significantly improve the micro-machining accuracy and efficiency of the external turning tools in CNC machines. Full article
►▼ Show Figures

Figure 1

5 pages, 448 KB  
Editorial
Direct Femtosecond Laser Writing of Micro-Optical Components
by Alessandra Nardini, Rebeca Martínez Vázquez and Behjat Sadat Kariman
Micromachines 2025, 16(10), 1142; https://doi.org/10.3390/mi16101142 - 4 Oct 2025
Viewed by 547
Abstract
Direct femtosecond laser writing (DLW), also known as two-photon polymerization (2PP), emerged as a true 3D micro/nano-structuring method in 1997 when Mauro and co-workers first demonstrated infrared femtosecond laser photopolymerization of a UV-curable resist [...] Full article
(This article belongs to the Section A1: Optical MEMS and Photonic Microsystems)
►▼ Show Figures

Figure 1

22 pages, 6737 KB  
Article
Molecular Dynamics Study on the Effect of Surface Films on the Nanometric Grinding Mechanism of Single-Crystal Silicon
by Meng Li, Di Chang, Pengyue Zhao and Jiubin Tan
Micromachines 2025, 16(10), 1141; https://doi.org/10.3390/mi16101141 - 2 Oct 2025
Viewed by 472
Abstract
To investigate the influence of surface films on the material removal mechanism of single-crystal silicon during nanogrinding, molecular dynamics (MD) simulations were performed under different surface-film conditions. The simulations examined atomic displacements, grinding forces, radial distribution functions (RDF), phase transformations, temperature distributions, and [...] Read more.
To investigate the influence of surface films on the material removal mechanism of single-crystal silicon during nanogrinding, molecular dynamics (MD) simulations were performed under different surface-film conditions. The simulations examined atomic displacements, grinding forces, radial distribution functions (RDF), phase transformations, temperature distributions, and residual stress distributions to elucidate the damage mechanisms at the surface and subsurface on the nanoscale. In this study, boron nitride (BN) and graphene films were applied to the surface of single-crystal silicon workpieces for nanogrinding simulations. The results reveal that both BN and graphene films effectively suppress chip formation, thereby improving the surface quality of the workpiece, with graphene showing a stronger inhibitory effect on atomic displacements. Both films reduce tangential forces and mitigate grinding force fluctuations, while increasing normal forces; the increase in normal force is smaller with BN. Although both films enlarge the subsurface damage layer (SDL) thickness and exhibit limited suppression of crystalline phase transformations, they help to alleviate surface stress release. In addition, the films reduce the surface and subsurface temperatures, with graphene yielding a lower temperature. Residual stresses beneath the abrasive grain are also reduced when either film is applied. Overall, BN and graphene films can enhance the machined surface quality, but further optimization is required to minimize subsurface damage (SSD), providing useful insights for the optimization of single-crystal silicon nanogrinding processes. Full article
►▼ Show Figures

Figure 1

20 pages, 4013 KB  
Review
Bioengineering 3D Pancreatic Cancer Models with Fibrotic Stroma for In Vitro Cancer Modeling
by Xingrun Lan, Keke Chen and Xiaoyun Wei
Micromachines 2025, 16(10), 1140; https://doi.org/10.3390/mi16101140 - 2 Oct 2025
Viewed by 393
Abstract
Pancreatic ductal adenocarcinoma (PDAC) remains highly lethal due to late diagnosis, high malignancy, and profound resistance to therapy. Traditional two-dimensional (2D) cell cultures fail to recapitulate the complex tumor microenvironment (TME), especially the fibrotic stroma, which is crucial for the progression of PDAC [...] Read more.
Pancreatic ductal adenocarcinoma (PDAC) remains highly lethal due to late diagnosis, high malignancy, and profound resistance to therapy. Traditional two-dimensional (2D) cell cultures fail to recapitulate the complex tumor microenvironment (TME), especially the fibrotic stroma, which is crucial for the progression of PDAC and drug response. In vitro three-dimensional (3D) models, which provide more physiologically relevant features such as tight cell–cell and cell-extracellular matrix (ECM) interactions, as well as 3D architecture, have been regarded as highly promising models in PDAC research. This review summarizes some representative in vitro PDAC models, including 3D spheroids, tumor-on-a-chip, bioprinted constructs, and patient-derived organoids (PDOs), particularly focused on the advances in bioengineering strategies for the integration of the key stomal components for microenvironment recapitulation and their applications. Additionally, we discuss the current challenges facing 3D models and propose potential strategies for constructing in vitro models that more accurately simulate the pathophysiology of the fibrotic stroma, aiming for their application in clinical settings. Full article
(This article belongs to the Special Issue 3D Tissue Engineering Techniques and Their Applications)
►▼ Show Figures

Figure 1

12 pages, 1130 KB  
Article
Experimental Study on Abrasive Flow Polishing of Grooves and Oil Holes of Aircraft Engine Main Bearing
by Qinghao Zhang, Jikun Yu and Mingyu Wu
Micromachines 2025, 16(10), 1139; https://doi.org/10.3390/mi16101139 - 1 Oct 2025
Viewed by 299
Abstract
This study addresses the challenges in machining the raceways and oil holes of aircraft engine bearing rings by conducting abrasive flow machining experiments on main bearing rings which had undergone ultra-precision grinding. Viscoelastic abrasive media containing cubic boron nitride of different particle sizes [...] Read more.
This study addresses the challenges in machining the raceways and oil holes of aircraft engine bearing rings by conducting abrasive flow machining experiments on main bearing rings which had undergone ultra-precision grinding. Viscoelastic abrasive media containing cubic boron nitride of different particle sizes is used during the experiments. The results show that bearing performance is improved significantly in terms of surface roughness and residual compressive stress consequently; the overall surface quality is raised. The machining process meets the precision requirements for the main bearings of this type of aircraft engine, validating the feasibility and effectiveness of Abrasive Flow Machining (AFM), and the foundation for further optimization of this process is set through this research. Full article
(This article belongs to the Special Issue Novel Processes for Cutting, Grinding and Polishing of Microstructured Surfaces)
►▼ Show Figures

Figure 1

28 pages, 3829 KB  
Review
Automated Platforms in C. elegans Research: Integration of Microfluidics, Robotics, and Artificial Intelligence
by Tasnuva Binte Mahbub, Parsa Safaeian and Salman Sohrabi
Micromachines 2025, 16(10), 1138; https://doi.org/10.3390/mi16101138 - 1 Oct 2025
Viewed by 461
Abstract
Caenorhabditis elegans is one of the most extensively studied model organisms in biology. Its advantageous features, including genetic homology with humans, conservation of disease pathways, transparency, short lifespan, small size and ease of maintenance have established it as a powerful system for research [...] Read more.
Caenorhabditis elegans is one of the most extensively studied model organisms in biology. Its advantageous features, including genetic homology with humans, conservation of disease pathways, transparency, short lifespan, small size and ease of maintenance have established it as a powerful system for research in aging, genetics, molecular biology, disease modeling and drug discovery. However, traditional methods for worm handling, culturing, scoring and imaging are labor-intensive, low throughput, time consuming, susceptible to operator variability and environmental influences. Addressing these challenges, recent years have seen rapid innovation spanning microfluidics, robotics, imaging platforms and AI-driven analysis in C. elegans-based research. Advances include micromanipulation devices, robotic microinjection systems, automated worm assays and high-throughput screening platforms. In this review, we first summarize foundational developments prior to 2020 that shaped the field, then highlight breakthroughs from the past five years that address key limitations in throughput, reproducibility and scalability. Finally, we discuss ongoing challenges and future directions for integrating these technologies into next-generation automated C. elegans research. Full article
(This article belongs to the Special Issue Advances in Microfluidic Chips for Chemical and Biomedical Applications)
►▼ Show Figures

Figure 1

12 pages, 2558 KB  
Article
Degradation and Damage Effects in GaN HEMTs Induced by Low-Duty-Cycle High-Power Microwave Pulses
by Dong Xing, Hongxia Liu, Mengwei Su, Xingjun Liu and Chang Liu
Micromachines 2025, 16(10), 1137; https://doi.org/10.3390/mi16101137 - 1 Oct 2025
Viewed by 339
Abstract
This study investigates the effects and mechanisms of high-power microwave on GaN HEMTs. By injecting high-power microwave from the gate into the device and employing techniques such as DC characteristics, gate-lag effect analysis, low-frequency noise measurement, and focused ion beam (FIB) cross-sectional inspection, [...] Read more.
This study investigates the effects and mechanisms of high-power microwave on GaN HEMTs. By injecting high-power microwave from the gate into the device and employing techniques such as DC characteristics, gate-lag effect analysis, low-frequency noise measurement, and focused ion beam (FIB) cross-sectional inspection, a systematic investigation was conducted on GaN HEMT degradation and failure behaviors under conditions of a low duty cycle and narrow pulse width. Experimental results indicate that under relatively low-power HPM stress, GaN HEMT exhibits only a slight threshold voltage shift and a modest increase in transconductance, attributed to the passivation of donor-like defects near the gate. However, when the injected power exceeds 43 dBm, the electric field beneath the gate triggers avalanche breakdown, forming a leakage path and causing localized heat accumulation, which ultimately leads to permanent device failure. This study reveals the physical failure mechanisms of GaN HEMTs under low-duty-cycle HPM stress and provides important guidance for the reliability design and hardening protection of RF devices. Full article
(This article belongs to the Section D1: Semiconductor Devices)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-92
Previous Issue
Back to TopTop