Micromachines最新文献

{"title":"Electrochemical and Optical Biosensors for Acetylcholine Monitoring in Neurodegeneration.","authors":"Juan Pablo Hervás-Pérez, Laura Muñoz-Oporto, María Moreno-Guzmán, Marta Sánchez-Paniagua","doi":"10.3390/mi17101122","DOIUrl":"https://doi.org/10.3390/mi17101122","url":null,"abstract":"<p><p>Acetylcholine (ACh) plays a pivotal role in cognition, learning, memory, and neuronal plasticity, and alterations in cholinergic neurotransmission are closely associated with neurodegenerative disorders, particularly Alzheimer's disease and related dementias. Consequently, the development of analytical tools capable of accurately monitoring ACh has attracted considerable interest in both neuroscience and clinical research. However, the determination of ACh remains challenging because of its low physiological concentrations, rapid enzymatic degradation, and the complexity of biological matrices. This review provides a comprehensive overview of recent advances in electrochemical and optical biosensors developed for ACh detection, with particular emphasis on progress reported between 2020 and 2026. The sensing principles, analytical performance, and technological characteristics of enzymatic and non-enzymatic electrochemical platforms, as well as colorimetric, fluorescent, surface plasmon resonance, and emerging molecular optical sensors, are critically discussed. Particular attention is given to the role of nanomaterials, signal-amplification strategies, miniaturized devices, wearable and implantable platforms, and approaches enabling real-time monitoring. Recent studies demonstrate remarkable improvements in sensitivity and detection limits; however, translation towards clinical applications remains limited by challenges related to selectivity in complex biological samples, biofouling, long-term stability, reproducibility, and the scarcity of validation studies involving authentic patient-derived specimens. Overall, current advances indicate a shift from proof-of-concept sensor development towards application-oriented platforms aimed at continuous neurochemical monitoring and point-of-care analysis. Future progress will depend on achieving robust performance in physiologically relevant environments and establishing clinically validated biosensing strategies for the assessment of cholinergic dysfunction in neurodegenerative diseases.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270104","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":"Magnetically Actuated Hydrogel-Based Microrobotic Structures with X-Ray Visibility for Targeted Drug Delivery in Vascular Environments.","authors":"Jiyu Jung, Geonhui Mun, Yoon-Gyung Sung, Kyongsu Lee, Van Du Nguyen, Gwangjun Go, Eunpyo Choi","doi":"10.3390/mi17101120","DOIUrl":"https://doi.org/10.3390/mi17101120","url":null,"abstract":"<p><p>In recent years, microrobots have attracted attention as minimally invasive therapeutic tools in biomedical applications, as they enable enhanced drug delivery efficiency through direct and localized transport. However, practical realization requires highly precise controllability and real-time responsiveness. In this study, we present a hydrogel-based microrobotic structure precisely and dynamically controlled in real time using externally applied magnetic fields. Chemical, structural, and magnetic characteristics were systematically analyzed, followed by experimental evaluation of targeting performance within a vascular-mimicking model under a phosphate-buffered saline (PBS) environment. Results demonstrate that sufficient visibility in X-ray imaging can be achieved depending on the concentration of embedded magnetic nanoparticles introduced during fabrication. Moreover, stable and real-time targeted navigation of the microrobotic structures was confirmed within specific threshold ranges of magnetic field strength and frequency. By effectively restricting off-target motion, the proposed system offers a minimally invasive medical platform that simultaneously ensures high stability and control precision.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"17 10","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149270223","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":"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":"Effect of Different Dominant Phase on NO₂-Sensing Properties of ZnO/SnO₂ Composites.","authors":"Jipeng Zhao, Zhigang Tao, Zhenyue Tu, Hongxia Bian, Jiankang Huang","doi":"10.3390/mi17101115","DOIUrl":"https://doi.org/10.3390/mi17101115","url":null,"abstract":"<p><p>The influence of different dominant phases on the gas-sensing properties of metal oxide n-n heterojunctions remains unclear. In this work, two kinds of phase-inverted ZnO/SnO₂ heterojunction composites (SZ and ZS series) are fabricated via a facile solid-state grinding method. Characterization results show that ZS-7 exhibits finer and more uniform grains with a specific surface area of 70.30 m²·g^-1. SZ-7 has a high oxygen vacancy content of 26.28%, and its Sn 3d characteristic peaks shift entirely toward higher binding energies, which verifies electron redistribution at the n-n heterojunction interface. Under UV irradiation, room-temperature NO₂ gas-sensing tests reveal that the ZS series exhibits overall superior performance to the SZ series. ZS-7 delivers a gas response of 46.49, with response/recovery times of 35 s/122 s and an ultralow detection limit of 74 ppb. Mechanism analysis indicates that the ZnO/SnO₂ heterojunction facilitates the separation and migration of photogenerated carriers under UV irradiation. The phase-inverted structure further accelerates photogenerated carrier separation and optimizes charge transport, ultimately improving gas-sensing performance. This study provides a novel design strategy for developing high-performance room-temperature NO₂ sensors.</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":"149270055","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":"Design of a 3D Aggregation Backbone Network-on-Chip Architecture for High-Speed Data Acquisition Systems.","authors":"Yunhui Deng, Chuanpei Xu, Wei Mo, Chunting Wan","doi":"10.3390/mi17101119","DOIUrl":"https://doi.org/10.3390/mi17101119","url":null,"abstract":"<p><p>Time-interleaved high-speed data acquisition (HS-DAQ) systems based on three-dimensional network-on-chip (3D NoC) architectures require efficient transmission of multi-channel sampled data. However, existing general-purpose NoC architectures are not well suited for the deterministic multi-source aggregation communication pattern of HS-DAQ systems, which may result in increased long-distance transmission overhead and localized traffic congestion. To address these issues, this paper proposes a 3D aggregation backbone network-on-chip architecture (3D AB-NoC) for HS-DAQ systems. This architecture is based on a 3D Mesh structure and enables the rapid transmission of long-distance aggregated data by establishing coarse-grained aggregation backbone subnets between defined aggregation routing nodes. Furthermore, a Backbone-Boosted XYZ (BB-XYZ) routing algorithm is proposed, which selects the next hop based on the remaining transmission distance of both the basic mesh path and the backbone path, thereby achieving coordinated routing for both local transmission and long-distance aggregation. Simulation results based on the Access Noxim platform demonstrate that the 3D AB-NoC maintains stable basic communication performance under general communication scenarios. In HS-DAQ communication scenarios, the proposed architecture reduces average latency by up to approximately 44%, improves throughput by approximately 29.3%, and significantly suppresses the growth of maximum latency under high-load conditions.</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":"149270310","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":"Protein-Based Biomaterials for Bio-Optoelectronics: A Review of Bio-Integrated and Biodegradable Optodevices.","authors":"Anna Merlo, Fosca Conti","doi":"10.3390/mi17101118","DOIUrl":"https://doi.org/10.3390/mi17101118","url":null,"abstract":"<p><p>Growing development of biomaterials has stimulated the biomedical sector to seek innovative alternatives to conventional medical technologies. Bio-optoelectronic devices are emerging as promising tools, integrating biologically derived components, biodegradable end-of-life approaches, and highly biocompatible materials with optoelectronic systems. The devices combine optical and electronic properties with biological interfaces, enabling more effective interaction with tissues and cellular systems. Applied research is motivated by the need to improve the efficacy and biocompatibility of medical devices while reducing invasiveness and adverse effects. Wearable devices and implants based on flexible, biodegradable, or bioinspired materials allow better adaptation to biological tissues and real-time monitoring or modulation of physiological processes. Proteins are attracting increasing attention due to their biocompatibility, biodegradability, mechanical flexibility, and ability to respond to optical and electrical stimuli. Furthermore, the combination of proteins with synthetic materials and nanomaterials in biohybrid platforms offers new opportunities for advanced bio-optoelectronic systems. This review summarizes key developments in bio-optoelectronic devices, focusing on protein-based materials; their roles in sensing, imaging, and neuromodulation; and their use in wearable, implantable, and biotech systems. Crucial challenges, including long-term stability and integration with biological systems, are also discussed, together with future perspectives for diagnostic and therapeutic applications.</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":"149270356","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}