Micromachines最新文献

{"title":"Effects of Structural and Electrical Defects on Vibration Suppression and Energy Harvesting Performance of Piezoelectric Metamaterial Beam.","authors":"Hongyan Wang, Xinru Jin, Guanglei Wang, Xiangwei Sun","doi":"10.3390/mi17101114","DOIUrl":"https://doi.org/10.3390/mi17101114","url":null,"abstract":"<p><p>This paper investigates the vibration suppression and energy harvesting performance of a locally resonant piezoelectric metamaterial beam (PMMB) with structural and electrical defects. The unit cell of a PMMB comprises a square aluminum substrate, two rubber plates sandwiching a piezoelectric plate, and a cylindrical stub on top. The structural and electrical defects are introduced by varying the material density of a stub, adjusting the spacing between the two adjacent piezoelectric local resonators (PLRs), and connecting inductors to selected PLRs, respectively. To investigate the theoretical band gap (BG), the effective BG (i.e., attenuation band), and the energy harvesting performance of defect-configured PMMB, supercell finite element were performed to obtain dispersion curves, while the six-PLR PMMB simulations were conducted to acquire transmission spectra and responding voltage outputs. Three distinct mechanisms are explored to enhance the performance of PMMB: defect states inside the effective BG for energy localization, defect-boundary interference for energy redistribution in the passband, and LC resonance in the shunted piezoelectric resonators for frequency-tunable energy harvesting. The results demonstrate that either stub-mass-reduced defect or substrate-length-increased spacing defect yield high voltages via energy localization in the effective BG, but they also narrow the effective BG. In contrast, tuning the center-to-center spacing of the two adjacent PLRs (near the excitation end) to an appropriate distance generates a dominant passband peak. The significant rises in both the far-end PLR voltage and the total voltage of the six PLRs clearly indicate energy redistribution within the passband. By selecting appropriate inductor parameters, LC-resonance-based electrical defects enable frequency-tunable voltage enhancement either at the effective BG edge or within the passband. Overall, this study provides comprehensive insight into how structural and electrical defects affect the response characteristics of the locally resonant PMMB.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unifying Field and Temperature Acceleration in Semiconductor Device Reliability Through Entropic Kinetics.","authors":"Liron Cohen, Lidor Bazon, Joseph B Bernstein","doi":"10.3390/mi17101116","DOIUrl":"https://doi.org/10.3390/mi17101116","url":null,"abstract":"<p><p>Time-dependent dielectric breakdown (TDDB) is an important failure mechanism that affects semiconductor device reliability. The degradation lifetime depends strongly on both electric field and temperature, yet these dependencies are commonly treated using separate empirical acceleration factors. This work develops a thermodynamic description in which electrical stress changes the accessible microscopic states of the dielectric and therefore contributes an entropic term to the Gibbs free energy. The resulting formulation separates the field-independent activation barrier, Ea, from a field-dependent entropic contribution characterized by α. This relation predicts a linear decrease in apparent activation energy with the logarithm of the electric field. Published TDDB data for SiO₂, high-k, low-k, and Cu/low-k dielectric systems exhibit this behavior. Independent temperature- and field-dependent measurements from the same source yield a common entropic field-energy scale of approximately 1.2 eV. A one-second reference field, E1sec, provides a physical time anchor that allows field and temperature acceleration to be compared without assuming a common pre-exponential factor across temperatures. For an absolute time temperature series, independently extracted values of α vary by 11.9% across three temperatures, while a fixed α produces a normalized relation with R² ≈ 0.97. The parameters Ea, α, and E1sec provide a compact thermodynamic representation of field- and temperature-dependent TDDB kinetics across the datasets examined here.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Broadband Microwave Absorber Operating Under High-Power Antenna Irradiation.","authors":"Wenjun Yu, Dong Yang, Zhong Cheng, Zheyu Zhao, Junyi Nangong, Tiancheng Han","doi":"10.3390/mi17101113","DOIUrl":"https://doi.org/10.3390/mi17101113","url":null,"abstract":"<p><p>A microwave absorber is important for reducing the scattering of airborne antennas and radio-frequency systems. However, absorbed electromagnetic energy is inevitably converted into heat, and high-power antenna irradiation may cause local temperature rise and safety hazards. In this work, we demonstrated how to overcome this bottleneck to be compatible with broadband absorption and to work under high-power electromagnetic irradiation. Through the analysis of the electromagnetic-thermal characteristics of typical periodic structural units, cross-shaped and square-ring resistive-film patterns were chosen to design a broadband absorber. Finally, a dual-layer structure consisting of a lower square-ring resistive-film layer and an upper cross-shaped resistive-film layer was designed using equivalent-circuit modeling and full-wave simulation. The fabricated absorber exhibited a measured reflection response below -10 dB from 5.1 to 18 GHz. When the absorber is illuminated by a high-power antenna, its steady-state temperature is only 59.7 °C. These results indicate that the proposed scheme can balance broadband microwave absorption and thermal-management capability, providing a feasible route for absorbers used in high-power antenna irradiation environments.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Regime-Based Theoretical and Visualization Framework for Droplet Formation in Microfluidic Co-Flow Systems.","authors":"Van Thanh Hoang, Doan Hung Vo, Quang Hieu Tran, Anh Quan Tran, Minh Thong Tran, Quoc-Thong Le-Van, Jin-Wei Liang, Hsi-Hsun Tsai","doi":"10.3390/mi17101117","DOIUrl":"https://doi.org/10.3390/mi17101117","url":null,"abstract":"<p><p>Droplet formation in microfluidic co-flow systems is essential for producing controlled emulsions in biomedical, pharmaceutical, chemical, and materials applications. Despite extensive studies of a wide range of operating conditions, existing predictive and nondimensional relations are generally restricted to specific flow regimes and physical mechanisms. In this study, we develop a regime-based theoretical and visualization framework for predicting droplet generation across three representative co-flow regimes: dripping, narrowing jetting, and widening jetting. The proposed framework combines force-balance and mass-conservation principles to derive explicit analytical expressions for droplet size and droplet-generation frequency in terms of key dimensionless parameters, including the outer capillary number, viscosity ratio, and flow-rate ratio. For dripping, droplet size decreases with increasing outer capillary number. In narrowing jetting, droplet size decreases while generation frequency increases due to jet stretching and thinning. In widening jetting, droplet size increases with flow-rate ratio. In addition, the influence of the viscosity ratio weakens as the value increases. The models are validated against experimental data from the literature and show good agreement in predicting droplet size and frequency across multiple flow regimes and operating conditions. This work provides a physics-guided, regime-aware reduced-order framework for analyzing and designing microfluidic co-flow droplet-generation systems.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Observer-Data-Path Decoupled Time-Domain ADC with Three-Stage Digital Background Calibration in 28 nm CMOS.","authors":"Chuan Qin, Bowen Liu, Runqiao Wang, Lecheng Li, Chaoyang Zhang","doi":"10.3390/mi17101110","DOIUrl":"https://doi.org/10.3390/mi17101110","url":null,"abstract":"<p><p>This paper presents an observer-data-path decoupled time-domain ADC with three-stage digital background calibration, designed and comprehensively verified through post-layout simulations in 28 nm CMOS for highly integrated micro-systems. In scaled nodes, the voltage-to-time converter front-end exhibits large-signal nonlinearity, while the time-to-digital converter (TDC) resolution drifts with PVT; conventionally these two errors are strongly coupled in the time domain, making concurrent calibration difficult. To break this coupling, the proposed observer-data-path decoupled architecture confines a single-bit pseudo-random dither to an observer path for error extraction and reconstructs the signal in a dither-free data path, thereby separating the calibration loops without degrading the SNDR. Building on this decoupling, a constant time-offset injection logic eliminates the gated ring oscillator-TDC dead-zone, and the three-stage calibration compensates the ADC gain error induced by TDC-resolution drift through VTC-gain tuning, regulates the non-integer dither ratio through Bang-Bang control, and suppresses the residual even- and odd-order nonlinearity through a dither-modulated threshold-crossing algorithm with EWMA-filtered LMS polynomial adaptation. In post-layout simulation at 1 GS/s, the calibration lifts the near-Nyquist SFDR from 50.3 to 67.0 dBc and the SNDR to 46.0 dB, and improves the INL to -0.15/+0.70 LSB. The design consumes 2.98 mW under nominal conditions and 3.89 mW at the worst-power PVT corner, corresponding to nominal and worst-case Walden FoMs of 18.3 and 23.9 fJ/conversion-step, respectively, within a 0.0024-mm² core.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electromechanical Modeling and Dimensionless Optimization of a Multilayer PZT-5H Energy Harvester for Vehicle Suspension Systems.","authors":"Swati Devi, Vijay Kumar Gupta, Ivan A Parinov","doi":"10.3390/mi17101111","DOIUrl":"https://doi.org/10.3390/mi17101111","url":null,"abstract":"<p><p>Vehicle suspension systems dissipate substantial vibration energy, generated by tyre-road interactions, most of which is lost as heat through damping. Recovering this energy can provide a sustainable power source for self-powered sensing and intelligent vehicle monitoring. This study presents a coupled electromechanical model of a quarter-car suspension incorporating a multilayer PZT-5H stack in series configuration for vibration energy harvesting. The proposed arrangement preserves effective suspension stiffness while enhancing electrical output through cumulative voltage generation. The governing mechanical and electrical equations are reformulated into a dimensionless framework, enabling generalized evaluation of mass ratio, stiffness ratio, damping, electromechanical coupling, and electrical load. The analytical model is independently verified using a MATLAB-Simulink (R2025b) implementation, while available experimental data are used only as an external benchmark rather than as direct full-scale validation. Parametric analysis shows that harvested power peaks near the suspension-bounce resonance, while stiffness ratio and mass ratio significantly influence strain transfer and inertial energy exchange, respectively. Taguchi-based design of experiments and ANOVA reveal that load resistance is the dominant factor, contributing approximately 63.6% and 58.5% of the variance for the undamped and damped models, respectively, followed by stiffness ratio (19.6% and 17.9%) and mass ratio (14.0% and 12.5%). The proposed framework integrates the series-connected piezoelectric configuration, dimensionless modeling, analytical-numerical verification, and statistical optimization to provide a unified methodology for designing suspension-integrated piezoelectric energy harvesters.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Engineering Application of a Vertically Installed FBG Sensor for Subgrade Strain Monitoring.","authors":"Jianping He, Haigang Wang, Tongchun Qin, Di Ning","doi":"10.3390/mi17101112","DOIUrl":"https://doi.org/10.3390/mi17101112","url":null,"abstract":"<p><p>Subgrade deformation under load is accumulated from the local compressive strain of each layer. Solely relying on the overall settlement monitoring at the top surface makes it difficult to reveal the internal strain distribution and the evolutionary characteristics of early damage. Therefore, acquiring the local compressive strain field along the depth direction is of great engineering significance for subgrade condition assessment and safety early warning. In this paper, a vertically installed FBG sensor (VI-FBG) with GFRP packaging suitable for layered strain measurement of subgrade is developed. The effectiveness of the sensor is verified by direct compression tests and compressive strain tests with the sensor embedded in concrete. Furthermore, the sensor was buried in the subgrade of a high-speed railway to carry out strain monitoring. The test results show that the sensor has favorable sensing performance, with a strain sensitivity of 1.2 pm/με and a temperature sensitivity of 16.84 pm/°C. The measured compressive strain of concrete is in good agreement with the theoretical value, and the relative error is less than 8%. The field monitoring data can truly reflect the vertical compressive strain during subgrade filling. The measured time-history curve exhibits good consistency with the displacement time-history curve obtained by the adjacent FBG settlement sensor. This study verifies that the sensor is applicable to the monitoring of local vertical compressive deformation of subgrade, and its GFRP encapsulation endows it with good engineering applicability.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149269978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pareto-Guided Process Optimization of Single-Crystal InP Chemical Mechanical Polishing: Balancing Material Removal Rate and Surface Roughness.","authors":"Jiayun Deng, Junjiang Zhou, Jiacheng Geng, Hua Wei, Hanbao Liu, Jiao Li, Shunjin Wang, Changlin Li, Tinglong Liu, Feng Hui","doi":"10.3390/mi17101108","DOIUrl":"https://doi.org/10.3390/mi17101108","url":null,"abstract":"<p><p>Single-crystal indium phosphide (InP) is an important substrate material for high-speed electronic and optoelectronic devices. Its relatively low hardness, brittleness, and sensitivity to polishing chemistry make it challenging to achieve both efficient material removal and low surface roughness during chemical mechanical polishing (CMP). In this study, response surface methodology (RSM) was combined with multi-objective particle swarm optimization and the Technique for Order Preference by Similarity to Ideal Solution (MOPSO-TOPSIS) to investigate the balance between material removal rate (MRR) and surface roughness (Ra). A three-factor Box-Behnken design was used to establish quadratic models incorporating H₂O₂ concentration, SiO₂ abrasive concentration, and polishing speed. The models gave coefficients of determination of 0.9898 for MRR and 0.9894 for Ra. Abrasive concentration had the strongest influence on both responses within the investigated ranges. Higher abrasive concentrations favored material removal, whereas lower roughness was obtained at intermediate concentrations and polishing speeds. A compromise condition of 9.79 wt% H₂O₂, 1.08 wt% SiO₂, and 54.33 rpm was evaluated experimentally. The predicted MRR and Ra were 3871.32 nm/h and 0.6747 nm, respectively, compared with measured values of 4283.79 nm/h and 0.712 nm. The corresponding relative deviations were 10.65% and 5.53%. These results provide a quantitative basis for selecting CMP parameters that balance removal efficiency and surface roughness in single-crystal InP polishing.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 220 GHz Integrated Sensing and Communication System Based on Orthogonal-Polarization Multiplexing.","authors":"Jicong Zhang, Zhankun Tang, Shuhang Shi, Ke Liu, Yinian Feng, Hui Peng, Bo Zhang","doi":"10.3390/mi17101109","DOIUrl":"https://doi.org/10.3390/mi17101109","url":null,"abstract":"<p><p>A 220 GHz integrated sensing and communication (ISAC) system based on orthogonal-polarization multiplexing is presented for simultaneous high-speed wireless communication and radar ranging. To achieve broadband operation, low insertion loss, and high polarization isolation, a dual-symmetric reverse-coupled orthomode transducer (OMT) is designed and fabricated. The OMT covers 170-260 GHz, with a measured return loss better than 15 dB and polarization isolation exceeding 45 dB, while relaxing the required fabrication tolerance to 10 μm. The OMT is integrated with solid-state frequency-conversion circuits, amplifiers, waveguide components, and a dual-polarized antenna to construct a dual-polarization transmit front end. The resulting system achieves polarization isolation exceeding 25 dB between the communication and radar channels over 204-222 GHz, together with a receiver noise figure of 9.8 dB at 220 GHz. Using coherent-reference techniques and real-time baseband processing, the system achieves a data rate of 2 Gbit/s over a distance of 0.25 m, with a bit error rate below 5×10-8. Radar ranging experiments using a single corner-reflector target at distances of 0.25 and 0.40 m yielded a maximum observed absolute ranging error of 1 cm. These results demonstrate the feasibility of orthogonal-polarization multiplexing for jointly supporting high-speed THz communication and centimeter-level radar sensing.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomistic Insights into Oxidation Mechanisms in Chemical-Mechanical Polishing of Diamond.","authors":"Kechong Wang, Yunkai Wang, Meng Li, Xiang Li, Chongjun Wu, Suye Hao, Ningchang Wang, Chen Li","doi":"10.3390/mi17101107","DOIUrl":"https://doi.org/10.3390/mi17101107","url":null,"abstract":"<p><p>Understanding the interfacial oxidation behavior during chemical-mechanical polishing (CMP) of diamond is important for controlling surface chemical modification and subsequent material removal. In this study, reactive force field molecular dynamics (ReaxFF MD) simulations were employed to comparatively investigate the atomistic evolution of interfacial oxidation, charge transfer, chemical species, and bond structures of single-crystal diamond in •OH- and H₂O₂-containing environments under different pressure conditions. The results show that oxidant chemistry and mechanical loading jointly regulate the kinetics and pathway selectivity of interfacial reactions. Elevated pressure promotes early-stage interfacial contact, surface activation, and oxidant consumption; however, the subsequent evolution of C-O bonds is also governed by oxidant-specific reaction kinetics and the availability of reactive species. In the •OH system, highly reactive radicals interact directly with mechanically activated carbon sites, whereas oxidation in the H₂O₂ system is additionally constrained by the stepwise decomposition of H₂O₂ and the generation of reactive intermediates, resulting in a comparatively moderated and decomposition-limited oxidation pathway. The interfacial reactions involve the formation and dynamic evolution of C-O, C-OH, and C-H structures, reflecting the competition between oxidation and hydrogenation. XPS measurements after H₂O₂-based CMP provide qualitative experimental evidence for the formation of oxygen-containing functional groups on the diamond surface, supporting the occurrence of interfacial oxidation. These findings provide atomistic insight into the coupled effects of oxidant chemistry and mechanical loading during diamond CMP and may assist in the rational design of oxidation-assisted polishing processes.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}