Micromachines最新文献

{"title":"Three-Dimensional Helical Antenna Array with Circular Polarization.","authors":"Hui Peng, Kecheng Ye, Wei Nie, Yuxiang Li","doi":"10.3390/mi17091055","DOIUrl":"10.3390/mi17091055","url":null,"abstract":"<p><p>In this paper, a 4 × 4 planar helical antenna (PHA) array fed by a three-dimensional substrate integrated waveguide (SIW) power splitter is presented. The 4 × 4 array is composed of four 1 × 4 PHA subarrays, and each subarray is fed by the SIW power splitter. Since the helical antenna is end-fire, it could not be integrated into a 4 × 4 array in a 2-D plane. In order to realize a 4 × 4 array, a SIW twist vertical transition structure is designed to connect the subarray with the SIW power splitter. Finally, the proposed 4 × 4 helical antenna array is implemented and fabricated for measurement. The center frequency of the PHA is 11 GHz, the impedance bandwidth (IBW) is 10.16-11.99 GHz (16.64%), and the axial ratio bandwidth (ARBW) is 10.53-11.47 GHz with the peak gain of 18.44 dBi. The simulation and measurement results match each other well; therefore, the effectiveness of the proposed design is verified.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609834/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062423","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":"Enhancing the Source-Side Transient Response of Logarithmic Double-Spiral Terahertz Photoconductive Antennas Using a Central-Feed-Boundary Tip Array.","authors":"Chao Xu, Shuaiqi Wang, Yu Zhang, He Dong, Jian Gao, Guofeng Wang","doi":"10.3390/mi17091053","DOIUrl":"10.3390/mi17091053","url":null,"abstract":"<p><p>The smooth central feed boundary of a logarithmic double-spiral terahertz photoconductive antenna can limit the spatial overlap between the high-field region and photogenerated carriers, thereby restricting the source-side transient response. We introduced a micrometer-scale tip array along the central feed boundary and investigated the influence of tip apex angle, height, and spacing through a transient semiconductor model in COMSOL Multiphysics. The photocurrent derivative, which is proportional to the emitted terahertz electric field under the transient-current approximation, was adopted as the source-side response metric. The tip array enhanced the response by redistributing the local bias field and bringing the carrier-collection boundary closer to the illuminated region. Within the investigated ranges, tip height produced the strongest response variation, whereas the influence of the apex angle remained limited over 10-50°, and further reducing <i>d</i> from 0.5 to 0.25 μm resulted in only a marginal response improvement. For <i>θ</i> = 30°, <i>h</i> = 1.0 μm, and <i>d</i> = 0.5 μm, the positive-peak and peak-to-peak enhancement ratios reached 100.1% and 103.9%, respectively. These results provide source-side design guidance for parameter selection while qualitatively considering geometric perturbation and fabrication practicality.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609888/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062454","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":"Thermal-Hydraulic Performance Optimization of Open Microchannel Heat Sinks with Integrated Front Triangular Ribs and Secondary Channels.","authors":"Jianlong Gong, Zhongliang Pan","doi":"10.3390/mi17091052","DOIUrl":"10.3390/mi17091052","url":null,"abstract":"<p><p>To enhance the comprehensive thermal-hydraulic performance of microchannel heat sinks (MCHS), this work proposed a novel open-type MCHS integrated with front triangular ribs and secondary channels. Firstly, numerical computations were carried out to compare the flow and heat transfer characteristics of seven distinct MCHS configurations, and identify the optimal hybrid geometry consisting of an open microchannel fitted with integrated front triangular ribs and secondary channels. Secondly, the effects of <i>H</i>₁ (height of open front triangular ribs) and <i>H</i>₂ (height of open secondary channels) on the thermal-hydraulic performance of the MCHS were systematically analyzed. The results revealed that the composite open MCHS obtained its peak performance evaluation criterion (<i>PEC</i>) value at <i>H</i>₁ = 0.15 mm and <i>H</i>₂ = 0.25 mm from separate single-factor parametric analyses for <i>H</i>₁ and <i>H</i>₂<i>,</i> at a mass flow rate of 0.9 g/s. Finally, a surrogate model correlating three structural parameters (<i>H</i>₁, <i>H</i>₂, <i>W</i>_w) with the optimization objective (<i>PEC</i>) was established based on orthogonal test data. This surrogate model was coupled with a genetic algorithm to perform global parameter optimization to maximize <i>PEC</i>. Relative to the original design and the reference geometry in other literature, the optimized design achieved maximum reductions of 15.3% in thermal resistance and 70.9% in pumping power, accompanied by a 55.7% improvement in <i>PEC</i>. This research provides theoretical support for the structural design of high-heat-flux microchannel cooling devices.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609355/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062389","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":"Novel Conductometric Chemosensor Based on Methylenebis(Phosphonic Acid)-Modified Calixarene for L-Arginine Determination.","authors":"Svitlana V Marchenko, Sergiy O Cherenok, Kseniia O Berketa, Veronika A Bakhmat, Olha V Soldatkina, Anna I Selikhova, Olga I Kalchenko, Galyna P Volynets, Oleksandr O Soldatkin, Vitaly I Kalchenko, Sergei V Dzyadevych, Abdelhamid Errachid, Viktoriya M Pyeshkova","doi":"10.3390/mi17091047","DOIUrl":"10.3390/mi17091047","url":null,"abstract":"<p><p>This study reports the synthesis of a novel methylenebisphosphonic acid calix[4]arene derivative and its application as a receptor layer in a conductometric chemosensor for the highly sensitive detection of L-arginine. The synthesized calixarene contains two methylenebisphosphonic acid fragments at the upper rim of the macrocycle, which serve as recognition sites for L-arginine, and two 3-(methylthio)propoxy groups at the lower rim, which enable immobilization on the gold electrode surface. The sensor based on synthesized calixarene demonstrated a pronounced response to L-arginine, which can be attributed to the cooperative interaction of the protonated amino and guanidinium groups of L-arginine with the methylenebisphosphonic acid groups of the calixarene receptor. Density functional theory (DFT) calculations were employed to elucidate the molecular interactions underlying the recognition of L-arginine by the calixarene receptor. The developed chemosensor demonstrated a low limit of detection for L-arginine (5.6 µM); a wide linear range (up to 1000 μM); a short response time (≤80 s); and a high response reproducibility (RSD = 1.3%). The stability constants determined by HPLC depended on the nature of the amino acid and ranged from logK_A = 4.26 for leucine to logK_A = 4.52 for L-arginine. Compared with previously reported L-arginine sensors, the developed conductometric chemosensor exhibits a competitive detection limit, a wider linear detection range, and significantly improved response reproducibility. The proposed calixarene-based chemosensor enables simple, highly sensitive, enzyme-free conductometric detection of L-arginine over a broad concentration range in aqueous solutions.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609174/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062283","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":"Bonding with a Benchtop UV Ozone Cleaner: A Practical Guide to Prepare a Microfluidic Chip.","authors":"Mirjam P M Poschmann, Lucas Holtorf, Igor Titov, Nahomy M Lizarde, Thomas Strunskus, Martina Gerken","doi":"10.3390/mi17091050","DOIUrl":"10.3390/mi17091050","url":null,"abstract":"<p><p>This study describes a procedure for preparing microfluidic chips made from polydimethylsiloxane (PDMS) layers. It uses an Ossila UV ozone cleaner for surface activation instead of the more common oxygen plasma treatment. The process is limited to PDMS@PDMS bonding, and it can be used when a low-cost procedure for a small number of microfluidic chips is required or when an oxygen plasma etcher is unavailable. The challenges of this process arise from the slight hardening of the PDMS surface when it is activated for at least 70 min, which is necessary for reliable bonding. Activation of the surface is confirmed by contact angle measurements. In a static simulation and lab tests, it is demonstrated that damage resulting from this hardening in conjunction with careless handling of the microfluidic chip is mitigated by incorporating predetermined break structures and using tubes with an outer diameter that is smaller than the inlets. Additionally, pre-polymerized PDMS glue and PDMS seals are suggested to ensure that the tubes are properly sealed. A burst test in air was performed to demonstrate the stability of the bonding and gluing. IR and XPS measurements were performed to investigate surface and bulk changes due to the treatment. To demonstrate the concept, six microfluidic chips were prepared and tested, achieving flow rates of at least 170 µL/min at ±180 mbar. Bonding remains stable up to a pressure of approximately 428 ± 60 mbar.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609066/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062339","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":"Task-Oriented Biomedical Microrobots: Access, Working Environment, Actuation, Body Design, Detection and Control.","authors":"Haoyi Sun, Aiwu Zhou, Tingxi Liu, Zhengnan Sun, Liang Zhou, Ji Hu, Ciprian Iliescu, Xiaosheng Zhang, Yi Zhang","doi":"10.3390/mi17091048","DOIUrl":"10.3390/mi17091048","url":null,"abstract":"<p><p>Biomedical microrobots are often classified by propulsion, materials or fabrication, but clinical translation depends on whether a device can complete a task in a specific biological setting. This review frames biomedical microrobots as task-oriented execution systems. Access and the working environment define the first constraints; actuation and body design convert inputs into useful local work; detection and control close the loop by linking measured states to the next action. Examples from vascular, gastrointestinal, pulmonary, luminal, cellular and biofilm-facing systems show that route, medium, motion, retention, payload function, imaging and post-task fate are coupled rather than separate design labels. Magnetic fields can resist flow or guide motion in confined anatomy, acoustic and optical inputs supply penetrative or local energy, and chemical or biological motors use cues from the surrounding medium. Body design then determines whether movement remains compatible with contact, release, sensing, retrieval and biocompatibility. By focusing on task execution rather than platform identity, this review clarifies what should be preserved in test models, what should be measured, and how fair comparisons can be made before translation.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609200/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062379","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":"Soft Mechanical Inductive Sensors: Principles, Design, and Applications.","authors":"Muhammad Awais, Gayatri Indukumar, Diana Cafiso, Lucia Beccai","doi":"10.3390/mi17091051","DOIUrl":"10.3390/mi17091051","url":null,"abstract":"<p><p>Soft mechanical inductive (SMI) sensors are emerging as a promising solution for advanced robotics, healthcare, and wearable devices, offering high precision, adaptability, and environmental robustness. These sensors leverage coil-based designs to achieve resilience against temperature variations, humidity, and mechanical wear, making them suitable for long-term operation in challenging environments. Existing reviews tend to focus narrowly on specific applications of coil-based inductive sensors, such as soft-robotic tactile sensing or biomedical devices, without systematically comparing design methodologies, fabrication techniques, or broader use cases, thereby lacking a unified perspective on the field. This review addresses this gap by analyzing recent developments in SMI sensors from theoretical concepts and practical design to their use cases. The review focuses on the working principles, design strategies, fabrication techniques, electronic interfaces, and, finally, the applications of coil-based SMI sensors. Key applications in soft robotics, prosthetics, and haptic devices are examined, highlighting the transformative potential of these sensors across diverse domains. Finally, the review discusses critical challenges, including sensitivity optimization, durability, and environmental interference, and outlines future directions to further advance this promising technology.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609018/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062297","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":"Hardware-Algorithm Co-Optimization of Weight-Update Protocols in Oxide-Based Synaptic Transistor Arrays for Neuromorphic Systems.","authors":"Yixin Cao, Jingsong Xia, Xiangyi Ding, Xin Wang, Jin Liu, Canhua Xu","doi":"10.3390/mi17091049","DOIUrl":"10.3390/mi17091049","url":null,"abstract":"<p><p>The transition from single-device characterization to array-level simulation remains a critical challenge in the development of three-terminal synaptic transistors for neuromorphic computing, as most existing simulation studies either extract parameters from a single representative device and apply them uniformly, or rely on weight-update strategies originally designed for two-terminal memristors. Here, we establish an experimentally calibrated behavioral simulation framework based on differential conductance-pair mapping (W = G⁺ - G^-, where G⁺ and G^- denote the conductances of the positive and negative devices of each pair), integrating exponential long-term potentiation/depression (LTP/LTD) update rules with a posteriori screening mechanism (isValid) to systematically investigate how update polarity, step size, nonlinearity, and conductance boundaries regulate network computational efficiency. Through comprehensive simulation on the Neural Circuit Policies network, we demonstrate that the update direction must strictly align with the matrix's role: the G^- channel requires unidirectional long-term depression inhibition, while the G⁺ channel can be frozen or bidirectionally updated. The optimal G^-LTD and G⁺G^-LTD strategies achieve accuracies of 0.9208 and 0.9481, respectively. Furthermore, we reveal a unique nonlinear gain effect under long-term depression > 0, where accuracy increases monotonically with nonlinearity level up to 0.9419. Device specification criteria are established: LTP-dominant updates favor large G_max, while LTD-dominant updates favor high G_min, with the G^-LTD and G⁺G^-LTD strategies showing accuracy fluctuations within ±0.005 across the tested boundary variations. Finally, the array-level implementation is validated through a functional-correctness check and device-parameter ablation experiments on a 23,715-weight array (47,430 differential conductance elements). This work provides an experimentally calibrated behavioral simulation platform and concrete algorithm-hardware co-design guidelines for future neuromorphic hardware, prioritizing synaptic devices with long-term depression > 0, a moderately elevated G_min, and asymmetric resource allocation toward LTD-side optimization.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609108/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062467","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":"Editorial for the Special Issue RF MEMS and Microsystems: From Reconfigurable Meta-Surfaces to Advanced MIMO and Miniature Antenna Systems.","authors":"Marco A Panduro","doi":"10.3390/mi17091045","DOIUrl":"10.3390/mi17091045","url":null,"abstract":"<p><p>The relentless expansion of modern wireless communications, high-resolution radar imaging, and decentralized mobile networks demands unprecedented adaptability, extreme compactness, and superior radiation efficiency from electromagnetic systems [...].</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609208/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062397","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":"Spurious-Mode Suppression in Sc_0.2Al_0.8N Film Lamb Wave Resonators and Filters with Arc-Shaped Apodization.","authors":"Kai Cai, Haiyang Li, Tingting Yang, Qinwen Xu, Yao Cai","doi":"10.3390/mi17091046","DOIUrl":"10.3390/mi17091046","url":null,"abstract":"<p><p>Lamb wave devices have the advantage of monolithic multi-frequency integration and show great application potential in mobile communications. However, their performance is often limited by spurious modes. In this work, an arc-shaped apodization electrode structure is proposed to suppress spurious modes in Sc_0.2Al_0.8N Lamb wave resonators (LWRs). By shortening the overlap length of the interdigital transducer electrodes at the edges, the energy coupling in the spurious-mode regions is reduced while the main-mode region is largely preserved. Finite element method (FEM) simulations confirm the suppression of spurious responses near the anti-resonant frequency. Based on the optimized design, typical and arc-shaped apodization LWRs and filters were fabricated. The fabricated arc-shaped apodization LWR exhibits an effective electromechanical coupling coefficient (keff2) of 3.9%. The corresponding filter operates at a center frequency of 1.774 GHz, with a -3 dB bandwidth of 20 MHz and a minimum insertion loss of 4.50 dB. Compared with the typical filter fabricated on the same wafer, the insertion loss is reduced by 1.22 dB. These results demonstrate the effectiveness of the proposed electrode apodization scheme for suppressing spurious modes in Sc_0.2Al_0.8N Lamb wave devices.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13609780/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149062268","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}