Micromachines最新文献

{"title":"Rapid and Ultrasensitive Sensor for Point-of-Use Detection of Perfluorooctanoic Acid Based on Molecular Imprinted Polymer and AC Electrothermal Effect.","authors":"Niloufar Amin, Jiangang Chen, Ngoc Susie Nguyen, Qiang He, John Schwartz, Jie Jayne Wu","doi":"10.3390/mi16030283","DOIUrl":"10.3390/mi16030283","url":null,"abstract":"<p><p>Perfluorooctanoic acid (PFOA) is one of the most persistent and bioaccumulative water contaminants. Sensitive, rapid, and in-field analysis is needed to ensure safe water supplies. Here, we present a single step (one shot) and rapid sensor capable of measuring PFOA at the sub-quadrillion (ppq) level, 4.5 × 10^-4 ppq, within 10 s. This innovative sensor employs a synergistic combination of a molecularly imprinted polymer (MIP)-modified gold interdigitated microelectrode chip and AC electrothermal effects (ACETs), which enhance detection sensitivity by facilitating the accelerated movement of PFOA molecules towards specific recognition sites on the sensing surface. The application of a predetermined AC signal induces microfluidic enrichment and results in concentration-dependent changes in interfacial capacitance during the binding process. This enables real-time, rapid quantification with exceptional sensitivity. We achieved a linear dynamic range spanning from 0.4 to 40 fg/L (4 × 10^-7-4 × 10^-5 ppt) and demonstrated good selectivity (~1:100) against other PFAS compounds, including perfluorooctanoic acid (PFOS), in PBS buffer. The sensor's straightforward operation, cost-effectiveness, elimination of the need for external redox probes, compact design, and functionality in relatively resistant environmental matrices position it as an outstanding candidate for deployment in practical applications.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11945770/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Status of Extended Threshold Wavelength Split-Off Band IR Detectors and Quantum Material-Based Extension for Room-Temperature Operation.","authors":"A G Unil Perera, Yanfeng Lao, Tara Jabegu, Sidong Lei","doi":"10.3390/mi16030286","DOIUrl":"10.3390/mi16030286","url":null,"abstract":"<p><p>This paper reports possible performance improvements of split-off band infrared detectors by using novel quantum materials. The report starts by describing the development of split-off band infrared detectors based on heterostructures with extended photoresponsivity beyond the energy band gap. The design modification demonstrated a new phenomenon of extending the threshold wavelength beyond the standard wavelength threshold (<i>λ</i>_t) determined by the energy gap (Δ) and the wavelength equation <i>λ</i>_t = 1.24/Δ with the dark current still governed by the original energy gap. However, to overcome the operating temperature challenges in AlGaAs/GaAs-based devices, the perspective of van der Waals quantum materials (vdW-QM)-based IR sensors is discussed regarding the aspects of heterostructure fabrication methods, theoretical modeling, and strategies that could help to overcome these issues. Through these discussions, the review paper aims to inspire upcoming innovations in developing novel IR photodetectors capable of operating within the atmospheric window at room temperature.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944272/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive Performance-Oriented Multi-Objective Optimization of Hemispherical Resonator Structural Parameters.","authors":"Xiaohao Liu, Xin Jin, Chaojiang Li, Yumeng Ma, Deshan Xu, Simin Guo","doi":"10.3390/mi16030287","DOIUrl":"10.3390/mi16030287","url":null,"abstract":"<p><p>The hemispherical resonant gyroscope is the highest-precision solid-state vibration gyroscope, widely applied in aviation, aerospace, marine, and other navigation fields. As the core component of the hemispherical resonant gyroscope, the design of its structural parameters directly influences the key performance parameters of the resonator-specifically, the thermoelastic damping quality factor and the minimum frequency difference from interference modes-affecting the operational accuracy and lifespan of the gyroscope. However, existing research, both domestic and international, has not clarified the effect of structural parameters on performance laws. Thus, studying the mapping relationship between the resonator's performance and structural parameters is essential for optimization. In this study, a hemispherical resonator with a midplane radius of 10 mm serves as the research object. Based on a high-precision finite element simulation model of an ideal hemispherical resonator, the mechanism of thermoelastic damping and the influence of structural parameters on performance are analyzed. A PSO-BP neural network mapping model is then developed to relate the resonator's structural and performance parameters. Subsequently, the NSGA-II algorithm is applied to perform multi-objective mapping of these parameters, achieving an optimized resonator with a 4.61% increase in the minimum frequency difference from interference modes and a substantial improvement in thermoelastic damping of approximately 70.41%. The comprehensive, performance-oriented multi-objective optimization method for the structural parameters of hemispherical resonators proposed in this paper offers a cost-effective approach to high-performance design and optimization, and it can also be applied to other manufacturing processes under specific conditions.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11945359/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of 450 MeV Kr Swift Heavy Ion Irradiation on GaN-Based Terahertz Schottky Barrier Diodes.","authors":"Yan Ren, Yongtao Yu, Shengze Zhou, Chao Pang, Yinle Li, Zhifeng Lei, Hong Zhang, Zhihong Feng, Xubo Song, Honghui Liu, Yongli Lou, Yiqiang Ni","doi":"10.3390/mi16030288","DOIUrl":"10.3390/mi16030288","url":null,"abstract":"<p><p>GaN-based terahertz (THz) Schottky barrier diodes (SBDs) are critical components for achieving high-power performance in THz frequency multipliers. However, the space applications of GaN-based THz SBDs are significantly constrained due to insufficient research on the effects of space irradiation. This work investigates the effects of 450 MeV Kr swift heavy ion (SHI) irradiation on the electrical characteristics and induced defects in GaN-based THz SBDs. It was found that the high-frequency performance of GaN-based THz SBDs is highly sensitive to Kr SHI irradiation, which can be attributed to defects induced in the GaN epitaxial layer by the irradiation. Low-frequency noise analysis reveals trap states located at an energy level of approximately 0.62 eV below the conduction band. Moreover, the results from SRIM calculation and photoluminescence spectra confirmed the presence of irradiation-induced defects caused by Kr SHI irradiation.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944912/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite Element Analysis of Soft-Pad Moldless Stamping of Bistable Circular Micro Shells.","authors":"Mark M Kantor, Asaf Asher, Rivka Gilat, Skava Krylov","doi":"10.3390/mi16030294","DOIUrl":"10.3390/mi16030294","url":null,"abstract":"<p><p>Bistable microstructures are promising for implementation in many mictroelectromechanical system (MEMS)-based applications due to their ability to stay in several equilibrium states, high tunability and unprecedented sensitivity to external stimuli. As opposed to the extensively investigated one-dimensional curved beam-type devices of this kind, microfabrication of non-planar two-dimensional bistable structures, such as plates or shells, represents a remarkable challenge. Recently reported by us, a new moldless stamping procedure, based on pressing a soft stamp over a thin suspended metallic film, was demonstrated to be a feasible direction for the fabrication of initially curved micro plates. However, reliable implementation of this fabrication paradigm and its further development requires better understanding of the role of the process parameters, and of the effect of both the plate and the stamp material properties on the shape of the formed shell and on the postfabrication residual stresses, and therefore on the shell behavior. The need for an appropriate choice of these parameters requires the development of a systematic modeling approach to the stamping process. Here, we report on a finite element (FE)-based methodology for modeling the processing sequences of a successfully fabricated aluminum (Al) micro shell of realistic geometry. The model accounts for the elasto-plastic behavior of the plate material, the nonlinear material behavior of the foam and the contact between them. It was found that the stamping pressure and the plate material parameters are the key parameters affecting the residual shell curvature as well as its shape. Consistently with previously presented experimental results, we show that the fabrication procedure partially relieves the prestresses emerging during preceding fabrication steps, leaving a nontrivial distribution of residual stresses in the formed shell. The presented analysis approach and results provide tools for designers and manufacturers of systems including micro structural elements of shell type.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944970/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-Dimensional Simulation on the Critical Diameter of Particles in Asymmetric I-Shaped DLD Arrays.","authors":"Jiangbo Wu, Zihan Yan, Yongqing He, Jie Liu, Yao Lv","doi":"10.3390/mi16030270","DOIUrl":"10.3390/mi16030270","url":null,"abstract":"<p><p>Deterministic lateral displacement (DLD) is a passive particle separation method based on microfluidic technology, with its separation mechanism primarily relying on particle size differences. Therefore, the critical separation size is of great significance in the design of DLD devices. The geometric asymmetry of the pillar array design significantly influences fluid behavior and critical particle size variations. This study first analyzed particle motion characteristics through particle trajectory observation experiments within asymmetric microfluidic chips. Subsequently, a two-dimensional numerical simulation method was employed to investigate the effects of three different ratios of lateral gap size to downstream gap size (G_x:G_y) on particle trajectories and flow field distribution. The results indicate that as G_x:G_y decreases, the upward flow rate gradually reduces, accompanied by changes in the flow field velocity distribution, causing particles to favor displacement mode. This study provides new theoretical foundations for the precise regulation of particle motion behavior and introduces novel insights for optimizing DLD device design.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946269/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in Triboelectric Nanogenerators for Microbial Disinfection.","authors":"Jinyoung Jeon, Donghyeon Kang, Sang-Woo Kim","doi":"10.3390/mi16030281","DOIUrl":"10.3390/mi16030281","url":null,"abstract":"<p><p>The global COVID-19 pandemic has highlighted the pivotal role of microbial disinfection technologies, driving the demand for innovative, efficient, and sustainable solutions. Triboelectric technology, known for efficiently converting ambient mechanical energy into electrical energy, has emerged as a promising candidate to address these needs. Self-powered electro-based microbial disinfection using triboelectric nanogenerators (TENGs) has emerged as a promising solution. TENGs have demonstrated effective disinfection capabilities in various settings, including water, air, surfaces, and wounds. This review explores the advancements in TENG-based microbial disinfection, highlighting its mechanisms and applications. By utilizing triboelectric technology, it provides comprehensive insights into the development of sustainable and efficient solutions for microbial control across diverse environments.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946175/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Novel Closed-Loop Single-Channel Time Division Multiplexing Detection Circuit for Hemispherical Resonator Gyroscope.","authors":"Qi Wang, Weinan Xie, Boqi Xi, Hanshi Li, Guoxing Yi","doi":"10.3390/mi16030273","DOIUrl":"10.3390/mi16030273","url":null,"abstract":"<p><p>The vector control method is applied to a whole angle hemispherical resonator gyroscope (HRG). The detection and control of the resonator vibration state are implemented using orthogonal <i>X</i>/<i>Y</i> channels. However, the performance of the HRG is limited by the asymmetry in the gain and phase delay of <i>X</i>/<i>Y</i> channels. To address these issues, a novel detection circuit is proposed. The circuit leverages the closed-loop characteristics to achieve symmetry and stability in the <i>X</i>/<i>Y</i> channel gain while simultaneously eliminating phase delays within the loop. Firstly, a closed-loop single-channel time division multiplexing circuit is designed to overcome the deficiencies of the traditional dual-channel circuit. Secondly, a model is developed to analyze the time division detection errors, and an improved demodulation method is proposed to mitigate detection errors. Lastly, experimental results demonstrate that the designed circuit successfully suppresses drift in both gain and phase delay within the loop, confirming the effectiveness of the proposed solution in enhancing the performance of the HRG.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944256/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly Dense TiO₂ Nanorods as Potential Electrode Material for Electrochemical Detection of Multiple Heavy Metal Ions in Aqueous Medium.","authors":"Sadia Ameen","doi":"10.3390/mi16030275","DOIUrl":"10.3390/mi16030275","url":null,"abstract":"<p><p>This study describes the direct deposition of extremely dense TiO₂ nanorods (NRs) on an ITO substrate for the improved detection of heavy metal ions (HMIs). A facile hydrothermal method was employed to synthesize TiO₂ NRs on the ITO substrate at ~130 °C. Synthesized TiO₂ NRs were analyzed for morphological, structural, and electrochemical properties. As an electrode material, TiO₂ NRs were used for the simultaneous detection of three HMIs (i.e., Cr³⁺, Cu²⁺, and Hg²⁺), which showed a remarkably high sensitivity of ~92.2 µA.mM^-1.cm^-2 for the Cu²⁺ ion. Relatively low sensitivities of ~15.6 µA.mM^-1.cm^-2 and ~19.67 µA.mM^-1.cm^-2 were recorded for the Cr³⁺ and Hg²⁺ ions, respectively. The fabricated TiO₂ NR-based HMI sensor showed an effective dynamic linear detection range with low LOD values of ~21.7 mM, 37 mM, and ~ 28.5 mM for Cr³⁺, Cu²⁺, and Hg²⁺, respectively. The TiO₂ NR-based HMI sensor exhibited efficient charge transfer over the electrode toward the trace detection of Cr³⁺, Cu²⁺, and Hg²⁺. Moreover, the reliability of the TiO₂ NR-based HMI sensor was assessed, which exhibited a promising stability of 30 days. The obtained results indicate that TiO₂ NRs grown on an ITO substrate are a promising electrode material for detecting hazardous Cr³⁺, Cu²⁺, and Hg²⁺ and might eventually be commercialized in the near future.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946551/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143719626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of Charged Nanodroplet Deposition into Microcavity Through Many-Body Dissipative Particle Dynamics.","authors":"Yiwei Jin, Jiankui Chen, Wei Chen, Zhouping Yin","doi":"10.3390/mi16030278","DOIUrl":"10.3390/mi16030278","url":null,"abstract":"<p><p>For a near-eye display, a resolution of over 10,000 pixels per inch (PPI) for the display device is needed to eliminate the \"screen door effect\" and have better display quality. Electrohydrodynamic (EHD) printing techniques, which have the advantages of a high resolution, wide material applicability and flexibility in patterning, have been widely used in the printing of high-resolution structures. However, due to factors such as the extremely small size of the droplets, the electric charge, the electric field, and the unavoidable positioning error, various deposition defects can occur. For droplets at a nanoscale, the dynamic deposition process is hard to observe. The continuum hypothesis fails and the fluid cannot be described by the traditional Navier-Stokes equation. In this work, the behaviors of charged nanodroplet deposition into a microcavity in an electric field are studied. The many-body dissipative particle dynamics (MDPD) method is used to examine the deformation of the nanodroplet during the impact process at a mesoscale. The dynamic process of charged droplet deposition into a microcavity under an electric field is revealed. Strategies for failure-free printing are proposed by analyzing the influences of the impact speeds, positioning errors, charge levels and electric intensities on the out-of-pixel spread length. The relationship between the internal charge moves and the deformation of the charged droplet in the deposition process is first discussed. The spreading theory of charged droplet deposition into a microcavity with a positioning error is established by analyzing the Coulombic capillary number. Moreover, the printing parameter space that results in successful printing is acquired.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11945935/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}