Micromachines

21 pages, 1917 KB

Open AccessArticle

Comparative Evaluation of Two Image-Analysis Software Platforms for Microfluidic Assessment of Red Blood Cell Deformability in Chronic Lymphocytic Leukemia

by Anika Alexandrova-Watanabe, Tihomir Tiankov, Aleksandar Iliev, Ariana Langari, Miroslava Ivanova, Lidia Gartcheva, Margarita Guenova, Emilia Abadjieva, Sashka Krumova and Svetla Todinova

Micromachines 2026, 17(3), 389; https://doi.org/10.3390/mi17030389 - 23 Mar 2026

Viewed by 333

Abstract

Red blood cell (RBC) deformability is a key determinant of microcirculatory flow and can be altered in hematological disorders such as chronic lymphocytic leukemia (CLL). This study aimed to evaluate RBC deformability under controlled microfluidic flow conditions and to assess the influence of [...] Read more.

Red blood cell (RBC) deformability is a key determinant of microcirculatory flow and can be altered in hematological disorders such as chronic lymphocytic leukemia (CLL). This study aimed to evaluate RBC deformability under controlled microfluidic flow conditions and to assess the influence of software platform choice on deformability quantification. RBC suspensions from healthy individuals and untreated CLL patients were analyzed using a microfluidic imaging system across a range of shear rates. A dedicated image-processing algorithm was developed and implemented in two software environments (LabVIEW and Python) to automatically detect deformed cells, measure major and minor cell axes, and calculate the deformability index (DI). Both analytical approaches demonstrated a shear-dependent increase in DI in healthy controls, whereas RBCs from CLL patients exhibited reduced deformability and a blunted response to increasing shear rates, particularly at intermediate shear rates. Although LabVIEW produced consistently higher absolute DI values than Python, both platforms showed strong correlation and preserved the same relative trends and group discrimination. These findings demonstrate that microfluidic image flow analysis provides a robust approach for assessing RBC biomechanics and highlight the importance of standardized image-processing workflows for reliable deformability quantification across software platforms. Full article

(This article belongs to the Special Issue Microfluidics for Bioanalysis: From Sample Preparation to Integrated Detection)

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19 pages, 8268 KB

Open AccessArticle

Enhanced Fringing Field Micro-Moisture Sensor with Elements Optimization

by Xiangrui Meng, Chong Li, Yunlong Lan, Lining Tan and Xiaoxiao Zhang

Micromachines 2026, 17(3), 388; https://doi.org/10.3390/mi17030388 - 23 Mar 2026

Viewed by 240

Abstract

This research demonstrates the principle and optimization methodology to create economic and miniaturized high-resolution micro-moisture sensors. The interdigitated fringe electric field-based moisture measurement principle is firstly investigated to sketch the key parameters of printed circuit board (PCB)-based sensors for further performance optimization. Then, [...] Read more.

This research demonstrates the principle and optimization methodology to create economic and miniaturized high-resolution micro-moisture sensors. The interdigitated fringe electric field-based moisture measurement principle is firstly investigated to sketch the key parameters of printed circuit board (PCB)-based sensors for further performance optimization. Then, a comprehensive study is conducted to analyze parameter variations with conclusions of suggested design rules to achieve higher measurement sensitivity. Two prototypes are designed and manufactured to validate the proposed theoretical contributions. Water droplets are employed to control the ambient relative humidity, which is adopted as the actual moisture variable in this work. A double-correlated sampling circuit is used for capacitance sensing. Both of them demonstrate a linearity of 1% and sensitivity of 0.1 pF/mg levels, but prototype 2 gains a better batch consistency, which is beneficial for commercialization. Further data analysis suggests that the equivalent input–output sensitivity reaches a level of 1.2403 pF/%RH (relative humidity), which is significantly higher than other types of published interdigitated fringe electric field-type moisture sensors. The optimized prototypes also show advantages of miniaturized size, low cost and high consistency, which can potentially impact the industry applications. Full article

(This article belongs to the Special Issue MEMS and NEMS Sensors: Innovations, Applications, and Future Directions in Micro/Nano Technologies)

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18 pages, 13779 KB

Open AccessArticle

Synthesis and Characterization of CNC/CNF/rGO Composite Films for Advanced Functional Applications

by Ghazaleh Ramezani, Ion Stiharu, Theo G. M. van de Ven, Hossein Ramezani and Vahe Nerguizian

Micromachines 2026, 17(3), 387; https://doi.org/10.3390/mi17030387 - 23 Mar 2026

Viewed by 360

Abstract

Developing advanced functional materials requires the synergistic integration of nanoscale reinforcements with tailored properties. In this work, composite films of cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and reduced graphene oxide (rGO) were synthesized using a combination of solution casting, high shear homogenization, vacuum [...] Read more.

Developing advanced functional materials requires the synergistic integration of nanoscale reinforcements with tailored properties. In this work, composite films of cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and reduced graphene oxide (rGO) were synthesized using a combination of solution casting, high shear homogenization, vacuum filtration, and environmentally friendly chemical reduction. The resulting CNC/CNF/rGO films exhibited a robust hierarchical structure with strong interfacial interactions, enabling exceptional mechanical properties, specifically a tensile strength of 215 MPa and a Young’s modulus of 18 GPa, alongside a continuous conductive network confirmed by frequency-independent electrical conductivity up to 30 kHz. Comprehensive dielectric characterization revealed frequency-dependent permittivity and low dielectric loss, aligning with Maxwell–Wagner theoretical predictions for heterogeneous composites. The composites also demonstrated thermal stability, with electrical conductivity increasing monotonically from 0 °C to 200 °C. These findings highlighted the CNC/CNF/rGO films’ suitability for applications in flexible electronics, electromagnetic shielding, packaging, and high-performance structural materials. Future optimization and modeling approaches, including fractional calculus, are recommended to further enhance multifunctionality and exploit the unique synergistic interactions intrinsic to nanocellulose–graphene oxide platforms. Full article

(This article belongs to the Section D：Materials and Processing)

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11 pages, 2565 KB

Open AccessFeature PaperEditor’s ChoiceArticle

Germanium-on-Silicon Waveguide-Integrated Photodiode with Dual Optical Inputs for Datacenter Applications

by Itamar-Mano Priel, Shai Cohen, Liron Gantz and Yael Nemirovsky

Micromachines 2026, 17(3), 386; https://doi.org/10.3390/mi17030386 - 23 Mar 2026

Viewed by 345

Abstract

As the exponential growth in advanced compute workloads drives intra-datacenter interconnects to ever increasing bitrates, optical networking equipment has risen to the challenge by shifting from NRZ signaling to bandwidth efficient modulation methods such as PAM4. As these modulation schemes introduce an inherent [...] Read more.

As the exponential growth in advanced compute workloads drives intra-datacenter interconnects to ever increasing bitrates, optical networking equipment has risen to the challenge by shifting from NRZ signaling to bandwidth efficient modulation methods such as PAM4. As these modulation schemes introduce an inherent SNR penalty, maintaining low bit error rates (BER) forces optical links to operate at significantly higher optical powers. However, increasing the optical power leads to photodetectors reaching one of their fundamental bottlenecks caused by the space-charge effect, limiting their ability to provide a high-speed response under high-power illumination. This work presents the design, fabrication, and characterization of a waveguide-integrated photodiode with dual optical inputs (DIPD) designed to overcome this limitation. Specifically, we demonstrate that combining a dual-fed architecture with targeted cross-sectional geometric optimizations effectively distributes the photocurrent density to delay the onset of space-charge saturation. Experimental validation demonstrates a high responsivity of ≈0.91 [A/W] (for O-band wavelengths) and a large electro-optic bandwidth (EOBW) of ≈58 [GHz], all under high-power illumination and CMOS driving voltages. Full article

(This article belongs to the Section A：Physics)

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12 pages, 2157 KB

Open AccessArticle

An Enhanced Q-Factor Cantilever Resonator in Viscous Liquids Using Strategic Perforation

by Song Qu and Cao Xia

Micromachines 2026, 17(3), 385; https://doi.org/10.3390/mi17030385 - 22 Mar 2026

Viewed by 276

Abstract

Cantilever resonators immersed in liquids experience significant viscous damping, which degrades the resonator’s quality factor (Q-factor) and lowers the signal-to-noise ratio. To address this challenge, a strategic perforation approach is proposed to enhance the Q-factor of cantilever resonators in viscous liquids. A distributed-parameter [...] Read more.

Cantilever resonators immersed in liquids experience significant viscous damping, which degrades the resonator’s quality factor (Q-factor) and lowers the signal-to-noise ratio. To address this challenge, a strategic perforation approach is proposed to enhance the Q-factor of cantilever resonators in viscous liquids. A distributed-parameter model based on the Rayleigh–Ritz method is developed to quantify the spatial distribution of structural stiffness and viscous damping. The analysis shows that material removal at the free end effectively reduces squeeze-film damping while maintaining stiffness. Resonator prototypes with different perforation designs are fabricated and tested in various viscous liquids. The results show that the free-end perforated cantilever (FPC) achieves a higher Q-factor compared to the conventional non-perforated cantilever (NPC). In an 18.5 mPa·s liquid, the FPC demonstrates a 346.2 % Q-factor enhancement and a 4.78 % frequency increase. These results provide a design guideline for high-performance cantilever resonators in liquid-phase sensing applications. Full article

(This article belongs to the Special Issue Advances in Nano/Micro Engineered & Molecular Systems)

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13 pages, 2399 KB

Open AccessArticle

A Composite Structure of Modified Silver Nanoparticles for Improving the Recognition Performance of Electrode

by Jiao Yang, Liqin Cui, Yibo Zhao and Xiaoping Wu

Micromachines 2026, 17(3), 384; https://doi.org/10.3390/mi17030384 - 21 Mar 2026

Viewed by 261

Abstract

To meet the demand for rapid detection of methylene blue residues in aquatic products, this study constructed a composite structure modified with silver nanoparticles on the surface of a glassy carbon sheet for precise detection. This composite film used the synergistic effect of [...] Read more.

To meet the demand for rapid detection of methylene blue residues in aquatic products, this study constructed a composite structure modified with silver nanoparticles on the surface of a glassy carbon sheet for precise detection. This composite film used the synergistic effect of the composite structure, which significantly enhanced the current response between the composite film and MB. The CV and EIS results demonstrated that this composite structure exhibited outstanding performance, endowing the composite film with the capability for sensitive detection of methyl blue. The results showed that the composite film detected methylene blue by differential pulse voltammetry, with a limit of detection as low as 1.6 nM. In the concentration range of 10 nM to 120 nM, the current intensity presented a good linear relationship with the concentration of MB. In addition, this composite film successfully identified methylene blue in aquatic products, with a recovery rate ranging from 81% to 113%. The results indicated that the composite film could be effectively applied to the sensitive detection of methylene blue in complex samples. This study provided a reliable and easy-to-construct electrochemical sensing platform for aquatic product safety monitoring. Full article

(This article belongs to the Special Issue Nanomaterial/Composite-Based Electrochemical (Bio)Sensing Microsystem)

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24 pages, 4666 KB

Open AccessArticle

Numerical Study on Heat Transfer Characteristics of Microchannel with Ferrofluid Under Influence of Magnetic Intensity

by Seong-Guk Hwang, Tai Duc Le and Moo-Yeon Lee

Micromachines 2026, 17(3), 383; https://doi.org/10.3390/mi17030383 - 21 Mar 2026

Viewed by 289

Abstract

Effective thermal management is critical for high-power lithium-ion batteries to mitigate excessive heat generation and ensure operational reliability. Failure to maintain a uniform temperature distribution can lead to accelerated capacity fading and severe safety risks, such as thermal runaway. In this study, a [...] Read more.

Effective thermal management is critical for high-power lithium-ion batteries to mitigate excessive heat generation and ensure operational reliability. Failure to maintain a uniform temperature distribution can lead to accelerated capacity fading and severe safety risks, such as thermal runaway. In this study, a ferrofluid-based magnetohydrodynamic (MHD) microchannel cooling system was numerically investigated to elucidate the influence of magnetic intensity, magnet geometry, and electrical boundary conditions on flow behavior and heat transfer performance for battery cooling applications. A fully coupled multiphysics model incorporating electromagnetic, fluid flow, and heat transfer phenomena was developed and validated against experimental and numerical data from the literature. The results show that increasing the applied voltage enhances current density and Lorentz force almost linearly, leading to significant flow acceleration and improved convective heat transfer. Electrical insulation effectively suppresses current leakage into the channel walls, increasing the average current density by up to 222% and the Lorentz force by more than 300%. Compared with a cylindrical magnet, a rectangular magnet provides a more uniform magnetic field distribution and stronger near-wall Lorentz forcing, resulting in superior cooling performance. Under a 4C discharge condition, the insulated rectangular magnet reduces the maximum battery temperature by approximately 30% and increases the average Nusselt number by up to 103% relative to the non-insulated case. The findings reveal the critical roles of magnetic-field-controlled flow symmetry and near-wall forcing in MHD-driven microchannels, and provide practical design guidelines for battery cooling systems with no moving mechanical parts and active electromagnetic flow control. Full article

(This article belongs to the Special Issue Complex Fluid Flows in Microfluidics)

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11 pages, 1438 KB

Open AccessArticle

Nanoscale Thin-Film Flexible Organic Field-Effect Transistors with Triple PMMA/SiO₂/ZnO Gate Insulator Layers

by Sundes Fakher, Furat AI-Saymari, Mohammed Mabrook and Hameed Al-Attar

Micromachines 2026, 17(3), 382; https://doi.org/10.3390/mi17030382 - 21 Mar 2026

Viewed by 321

Abstract

Organic field-effect transistors (OFETs) incorporating a triple insulating layer of polymethyl methacrylate (PMMA), silicon dioxide (SiO₂), and zinc oxide (ZnO) were successfully fabricated on glass and on flexible PET substrates. The insulating layers significantly enhanced device performance, with the OFETs achieving [...] Read more.

Organic field-effect transistors (OFETs) incorporating a triple insulating layer of polymethyl methacrylate (PMMA), silicon dioxide (SiO₂), and zinc oxide (ZnO) were successfully fabricated on glass and on flexible PET substrates. The insulating layers significantly enhanced device performance, with the OFETs achieving field-effect mobility (µ) values more than twice as high as those reported in the literature. Specifically, mobility values of ~6.75 cm²/V·s were recorded on glass, ~7.14 cm²/V·s on flexible substrates before bending, and ~6.88 cm²/V·s on flexible substrates after bending. Threshold voltages (V_th) of −7 V and −9 V were estimated for the flexible OFETs before and after bending, respectively, along with a high on/off current ratio, exceeding 10³ for all devices. Minimal hysteresis in the transfer and output characteristics indicated excellent, trap-free interaction between the insulating layers and the pentacene. The high dielectric constant of the PMMA/SiO₂/ZnO triple insulating layers was identified as a critical factor driving the exceptional performance, stability, and low hysteresis of the OFETs. These results underscore the pivotal role of advanced insulating layers in optimizing OFET performance and durability. Full article

(This article belongs to the Section D1: Semiconductor Devices)

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11 pages, 1844 KB

Open AccessArticle

Fs-Ablated Trenches on the Surface of Microsphere for Whispering Gallery Modes Cleaning

by Hiba A. Rizk, Viktor A. Simonov, Vadim S. Terentyev, Vladislav E. Fedyaj, Andrey E. Simanchuk, Alexander V. Dostovalov and Sergey A. Babin

Micromachines 2026, 17(3), 381; https://doi.org/10.3390/mi17030381 - 21 Mar 2026

Viewed by 256

Abstract

This study addresses the problem of whispering gallery mode (WGM) selection in spherical microresonators by means of their femtosecond micro-processing. The proposed method involves fabrication on the microsphere surface of defects playing the role of scattering elements for higher-order modes with low azimuthal [...] Read more.

This study addresses the problem of whispering gallery mode (WGM) selection in spherical microresonators by means of their femtosecond micro-processing. The proposed method involves fabrication on the microsphere surface of defects playing the role of scattering elements for higher-order modes with low azimuthal mode indices. These two T-shaped trenches are created using femtosecond laser ablation, with a depth of 2 microns, gap of 30 microns between them, and each of length of 20 microns along the equatorial direction. A tapered fiber with a sub-micron waist diameter serves as the excitation element for WGMs. This method allows for spectral purification of the WGMs, reducing the number of resonances by 180 times, with a quality factor of

Q > 10^{5}

for the non-inverted spectrum in the form of resonance dips. Additionally, an inverted spectrum with narrow resonance peaks of about 35%, low background level and single mode regime with 3 dB side peak suppression has been simultaneously achieved in the taper transmission, for the first time to our knowledge. The latter was obtained by exciting the microsphere at the taper waist. These results hold promise for the development of narrowband filters, laser mode selectors, and optical sensors based on microresonators. Full article

(This article belongs to the Special Issue Micro/Nanomanufacturing and Cross-Scale Fabrication: Methods, Systems, and Applications)

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25 pages, 5767 KB

Open AccessArticle

Dragonfly-Wing-Inspired Bluff-Body Piezoelectric Harvester for Efficient Low-Wind-Speed Energy Harvesting

by Zhiyong Zhou, Xinyu Shang, Yebao Xia and Pei Zhu

Micromachines 2026, 17(3), 380; https://doi.org/10.3390/mi17030380 - 20 Mar 2026

Viewed by 326

Abstract

Inspired by the wing-opening morphology of dragonflies, a series of bio-inspired dragonfly-shaped bluff bodies are designed and investigated, and further integrated into a piezoelectric wind energy harvester. The energy-harvesting performance and aerodynamic responses of bluff-body configurations with different wing-opening angles (0°, 15°, 30°, [...] Read more.

Inspired by the wing-opening morphology of dragonflies, a series of bio-inspired dragonfly-shaped bluff bodies are designed and investigated, and further integrated into a piezoelectric wind energy harvester. The energy-harvesting performance and aerodynamic responses of bluff-body configurations with different wing-opening angles (0°, 15°, 30°, 45°, and 60°) are comparatively analyzed through a combination of numerical simulations and wind tunnel experiments. Experimental results demonstrate pronounced differences among the configurations in the low wind speed regime. Specifically, the prototype with α = 0° achieves relatively higher output under very low wind speeds, whereas the α = 15° configuration exhibits the best overall performance across the entire tested wind speed range. Taking the α = 15° case as an example, the cut-in wind speed is reduced to 1.7 m/s, while the maximum RMS voltage and output power are increased by 20.16% and 44.39% compared with the cuboid bluff body, and by 50.95% and 127.84% compared with the cylinder bluff body, respectively. Further CFD results reveal that, at specific wing-opening angles, the dragonfly-shaped bluff body undergoes a coupled vortex-induced vibration (VIV) and galloping response, enabling certain configurations to sustain stable oscillations with large amplitudes over a relatively wide wind speed range. Within the investigated parameter range, an appropriate selection of the wing-opening angle effectively balances the cut-in capability and output stability under low wind speed conditions. These findings provide useful design guidelines for flow-induced vibration-based wind energy harvesters operating in low wind speed environments. Full article

(This article belongs to the Special Issue Research Progress on Piezoelectric Energy Harvesting Devices)

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16 pages, 2570 KB

Open AccessArticle

Tunable Bandpass Filtering in Coupled Nanodrums Enabled by 1:1 Internal Resonance

by Yikun Liu, Jiaxin Miao, Haoran Wang, Jinghong Tang, Cao Xia and Xiaoyu Liu

Micromachines 2026, 17(3), 379; https://doi.org/10.3390/mi17030379 - 20 Mar 2026

Viewed by 329

Abstract

In recent years, microelectromechanical systems (MEMS) filters exploiting structural nonlinearity and coupled resonance have enabled programmable passband shaping beyond traditional single-peak designs, yet they still face low operating frequencies and limited electrical tuning range. Here, leveraging 1:1 internal resonance, we propose a gate-programmable [...] Read more.

In recent years, microelectromechanical systems (MEMS) filters exploiting structural nonlinearity and coupled resonance have enabled programmable passband shaping beyond traditional single-peak designs, yet they still face low operating frequencies and limited electrical tuning range. Here, leveraging 1:1 internal resonance, we propose a gate-programmable tuning strategy for two-dimensional (2D) material-based nanoelectromechanical systems (NEMS), enabling high-frequency operation and wide-range reconfigurability. Benefiting from the high resonant frequency and wide electrostatic tunability of 2D materials such as MoS₂, our theoretical analysis indicates wide-range programmability up to

f / f_{0} \approx 200 %

. Sweeping

V_{g 1} = V_{g 2}

from 9 to 16 V while maintaining

\approx 1 : 1

frequency matching shifts the passband upward quasi-linearly at

4.4 ~ MHz / V

. In contrast, with the coupling strength nearly unchanged, mV-level bias mismatch perturbs the frequency ratio by

10^{- 5}

, enabling highly sensitive bandwidth trimming from 3.18 to 5.20 kHz, supporting a two-step strategy of coarse center-frequency tuning followed by fine bandwidth control. To broaden the bandwidth, we further analyze a three-drum case: with

V_{g 1} = V_{g 2} = V_{g 3} = 16 V

, the bandwidth reaches 21.79 kHz with a 5056.05 dB/MHz transition slope and 0.95 dB ripple, which is nearly 4 times wider than the two drum case with the same gate voltage. This study shows that 1:1 internal resonance can be used to tune the bandpass response of NEMS resonators. All results are obtained from theoretical modeling and numerical simulations. Full article

(This article belongs to the Special Issue Novel RF Nano- and Microsystems)

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17 pages, 4195 KB

Open AccessArticle

Design and Implementation of a Low-Noise Analog Front-End Circuit for MEMS Capacitive Accelerometers

by Keru Gong, Jiacheng Li, Xiaoyi Wang, Huiliang Cao and Huikai Xie

Micromachines 2026, 17(3), 378; https://doi.org/10.3390/mi17030378 - 20 Mar 2026

Viewed by 389

Abstract

This paper presents a low-noise analog front-end (AFE) integrated circuit (IC) circuit for capacitive micro-electromechanical system (MEMS) accelerometers that can be used for optical image stabilization (OIS) in various optical imaging systems. The AFE circuit design features a fully differential chopper stabilization technique [...] Read more.

This paper presents a low-noise analog front-end (AFE) integrated circuit (IC) circuit for capacitive micro-electromechanical system (MEMS) accelerometers that can be used for optical image stabilization (OIS) in various optical imaging systems. The AFE circuit design features a fully differential chopper stabilization technique that efficiently minimizes low-frequency 1/f noise and parasitic coupling. The AFE circuit chip is fabricated in a 0.18

μ

m complementary metal-oxide-semiconductor (CMOS) technology and co-packaged with an x-axis capacitive MEMS accelerometer based on a silicon-on-glass (SOG) process. The SOG accelerometer has a footprint of 1000

μ m

\times

950

μ m

. The packaged system demonstrates a sensitivity of 342 mV/g and a nonlinearity of 1.1% between −1 g and +1 g, a dynamic range of 88 dB, and an equivalent noise floor of 14

μ g / \sqrt{H z}

. Full article

(This article belongs to the Special Issue Advancing MEMS/MOEMS Sensors: AI-Driven Optimization and Emerging Applications)

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18 pages, 6963 KB

Open AccessArticle

First-Principles Calculations and PMUT Applications of Piezoelectric Thin-Film Materials

by Chengwei Che, Shanqing Yi, Caishuo Zhang, Xinyi Zheng, Xingli He and Dacheng Xu

Micromachines 2026, 17(3), 377; https://doi.org/10.3390/mi17030377 - 20 Mar 2026

Viewed by 324

Abstract

High-performance piezoelectric micromachined ultrasonic transducers (PMUTs) are crucial for portable medical imaging and sensing. The efficiency of advanced PMUTs relies on high-quality piezoelectric thin films and optimized device designs. However, variability in common piezoelectric thin films like Sc_xAl_1−xN (ScAlN) [...] Read more.

High-performance piezoelectric micromachined ultrasonic transducers (PMUTs) are crucial for portable medical imaging and sensing. The efficiency of advanced PMUTs relies on high-quality piezoelectric thin films and optimized device designs. However, variability in common piezoelectric thin films like Sc_xAl_1−xN (ScAlN) and PbZr_1−xTi_xO₃ (PZT) often leads to inaccurate material parameters—especially those derived from thick ceramics. To enhance simulation accuracy in standard designs affected by these inconsistencies, this work introduces an optimization framework combining first-principles calculations with multiphysics simulations. First, the intrinsic properties of PZT and ScAlN are analyzed through atomistic calculations, confirming that PZT, with its higher electromechanical coupling coefficient, is better suited for actuation. The parameters obtained from these calculations calibrate the finite-element model, addressing issues of missing or inaccurate data in commercial software libraries. Next, an efficient analytical acoustic-field model is developed. Compared to full-wave simulations in COMSOL, this model significantly reduces computational cost while maintaining accuracy, allowing for quicker scanning and optimization of large-array topologies. Additionally, results demonstrate that each individual hexagonal PMUT element outperforms a comparable circular element, achieving a peak SPL of 90.4 dB at 4.9 MHz versus 89.7 dB at 2.8 MHz. This higher acoustic output and operating frequency enable improved spatial resolution and sensitivity. This modeling approach, based on intrinsic material properties, provides a solid theoretical foundation for designing high-precision, low-power ultrasonic devices. Full article

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12 pages, 2082 KB

Open AccessArticle

Design and Experimental Validation of a Dynamic Frequency Sweeping Algorithm for Optimized Impedance Matching in Semiconductor RF Power Systems Under Pulse-Mode Operation

by Zhaolong Fan, Zhifeng Wang, Long Xu, Lili Hou, Long Yao, Siao Zeng and Mingqing Liu

Micromachines 2026, 17(3), 376; https://doi.org/10.3390/mi17030376 - 20 Mar 2026

Viewed by 337

Abstract

The design and implementation of a dynamic frequency sweeping algorithm for a 3 kW RF power source are underpinned by theoretical principles aimed at optimizing impedance matching under pulse-mode operation. The algorithm dynamically adjusts the output frequency within a predefined range to align [...] Read more.

The design and implementation of a dynamic frequency sweeping algorithm for a 3 kW RF power source are underpinned by theoretical principles aimed at optimizing impedance matching under pulse-mode operation. The algorithm dynamically adjusts the output frequency within a predefined range to align the source impedance Z_source with the conjugate of the load impedance Z*_load, maximizing the power transfer efficiency and minimizing the reflection coefficient Γ. This is achieved by leveraging the maximum power transfer theorem and adapting to dynamic load variations, such as those induced by the plasma state transitions. The algorithm incorporates adaptive step size adjustments based on the rate of change of Γ, predictive frequency initialization using historical data, and real-time impedance monitoring to ensure efficient convergence within the constrained pulse “ON” time (TON). Integration with pulse mode requires synchronization with the pulse signal, fast convergence, and optimized search strategies. Experimental validation on a 13.56 MHz, 3 kW Automatic Sweep Generator testbed operating at 20 kHz pulse modulation with a 50% duty cycle demonstrates a linear and stable sweep, achieving impedance matching and low reflected power within 5.0172 ms. These findings highlight the algorithm’s potential for high-precision applications, such as RF plasma excitation, and underscore the importance of adaptive techniques in dynamic RF systems. Full article

(This article belongs to the Special Issue Emerging Technologies and Applications for Semiconductor Industry)

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11 pages, 3987 KB

Open AccessArticle

On-Demand Droplet Routing and Splitting Using Independently Addressable Interdigitated Electrodes

by Yunus Aslan

Micromachines 2026, 17(3), 375; https://doi.org/10.3390/mi17030375 - 20 Mar 2026

Viewed by 406

Abstract

Droplet microfluidics enables precise manipulation of picoliter-to-nanoliter-scale droplets and supports key operations such as merging, splitting, sorting, and trapping, facilitating controlled handling of minute fluid volumes. These capabilities have significantly advanced high-throughput drug discovery, single-cell analysis, molecular diagnostics, and synthetic biology. Among these [...] Read more.

Droplet microfluidics enables precise manipulation of picoliter-to-nanoliter-scale droplets and supports key operations such as merging, splitting, sorting, and trapping, facilitating controlled handling of minute fluid volumes. These capabilities have significantly advanced high-throughput drug discovery, single-cell analysis, molecular diagnostics, and synthetic biology. Among these operations, droplet splitting is particularly important for multi-step biochemical assays and parallel processing. Splitting strategies can be broadly categorized as passive, relying on channel geometry or microstructures, or active, employing external stimuli such as thermal, magnetic, acoustic, or electric fields. Electric-field-based methods are especially attractive due to their rapid response and tunability; however, many reported systems require relatively high operating voltages. Here, we present a low-voltage microfluidic platform that integrates tilted interdigitated electrodes (IDEs) with an asymmetric Y-junction to enable electrically tunable droplet splitting and sorting within a single device architecture. Two independently addressable tilted IDE arrays generate localized electric-field gradients that induce dielectrophoretic droplet deflection at moderate voltages. By adjusting the applied voltage amplitude and selectively activating the electrode arrays, droplets can be dynamically routed into designated outlets or deterministically split in real time, providing adaptable electrohydrodynamic control with minimal structural complexity. Full article

(This article belongs to the Section E：Engineering and Technology)

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19 pages, 2861 KB

Open AccessArticle

Fault Detection and Isolation of MEMS IMU Array Based on WOA-MVMD-GLT

by Hanyan Li, Fayou Sun, Jingbei Tian, Xiaoyang He and Ting Zhu

Micromachines 2026, 17(3), 374; https://doi.org/10.3390/mi17030374 - 19 Mar 2026

Viewed by 272

Abstract

The stable and accurate output of the inertial measurement unit array (IMU) of a micro-electro-mechanical system (MEMS) is the key to ensuring the data fusion of the MEMS IMU array. However, due to the large number of MEMS IMUs contained in the MEMS [...] Read more.

The stable and accurate output of the inertial measurement unit array (IMU) of a micro-electro-mechanical system (MEMS) is the key to ensuring the data fusion of the MEMS IMU array. However, due to the large number of MEMS IMUs contained in the MEMS IMU array, it is susceptible to interference and has difficulty avoiding failures. The output of the MEMS IMU contains noise, outliers, and other related errors, which can seriously lead to low fault detection and isolation accuracy in the MEMS IMU. In this study, a new method of fault detection and isolation based on multivariate variational mode decomposition (MVMD), a whale optimization algorithm (WOA), and a generalized likelihood test (GLT) is proposed, which is called WOA-MVMD-GLT. Firstly, a multi-index fitness function WOA is proposed to optimize the parameters of MVMD. Secondly, MVMD is used to extract the features of the MEMS IMU’s signals. Finally, a GLT is used to construct a fault detection function and a fault isolation function to detect and isolate the faults of gyroscopes and accelerometers. The experimental results show that the method proposed in this paper can significantly reduce the false alarm rate and false isolation rate. Full article

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16 pages, 2380 KB

Open AccessArticle

Self-Regulating Wind Speed Adaptive Mode Switching for Efficient Wind Energy Harvesting Towards Self-Powered Wireless Sensing

by Ruifeng Li, Chenming Wang, Yiao Pan, Jianhua Zeng, Youchao Qi and Ping Zhang

Micromachines 2026, 17(3), 373; https://doi.org/10.3390/mi17030373 - 19 Mar 2026

Viewed by 341

Abstract

Wind energy harvesting based on triboelectric nanogenerators (TENGs) is a promising solution for powering distributed Internet of Things (IoT) nodes, yet its practical efficiency and stability are often hindered by the fluctuating and unpredictable nature of wind. Here, we propose a self-regulating TENG [...] Read more.

Wind energy harvesting based on triboelectric nanogenerators (TENGs) is a promising solution for powering distributed Internet of Things (IoT) nodes, yet its practical efficiency and stability are often hindered by the fluctuating and unpredictable nature of wind. Here, we propose a self-regulating TENG (SR-TENG) that leverages the synergistic effects of centrifugal, elastic, and frictional forces to automatically switch between non-contact and contact modes based on wind speed. This configuration achieves an ultra-low start-up wind speed of 0.86 m/s, ensures sustainable high-performance output across a broad wind speed range, and exhibits excellent durability with no observable performance degradation during 23,000 s of continuous operation at 375 rpm. Systematic structural optimization enables the SR-TENG to reach a peak open-circuit voltage of 140 V, a short-circuit current of 12.5 μA, and a transferred charge of 300 nC at 375 rpm. When integrated with a customized power management circuit, the system delivers a 30.39-fold increase in effective output power at a 1 MΩ load and a 4-fold faster charging rate for a 10 μF capacitor. For practical validation, the harvested ambient wind energy successfully powers a wireless temperature-humidity sensor for real-time cloud data transmission. These results highlight that the SR-TENG holds great potential for advanced wind energy harvesting and self-powered sensing applications in distributed IoT systems. Full article

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17 pages, 2066 KB

Open AccessArticle

Experimental Study on an Inclined Cylindrical Piezoelectric Energy Harvester

by Hao Li, Chongqiu Yang, Wenhui Li, Rujun Song and Xiaohui Yang

Micromachines 2026, 17(3), 372; https://doi.org/10.3390/mi17030372 - 19 Mar 2026

Viewed by 265

Abstract

Energy harvesting plays a pivotal role in enabling sustainable power supply for the Internet of Things and distributed sensor networks, particularly for low-power devices. Piezoelectric energy harvesters based on vortex-induced vibrations offer a promising solution for low-wind-speed applications, yet their performance is constrained [...] Read more.

Energy harvesting plays a pivotal role in enabling sustainable power supply for the Internet of Things and distributed sensor networks, particularly for low-power devices. Piezoelectric energy harvesters based on vortex-induced vibrations offer a promising solution for low-wind-speed applications, yet their performance is constrained by limited bandwidth and sensitivity to wind speed variations. This study addresses these limitations by proposing a novel multi-parameter adjustable piezoelectric energy harvester featuring an inclined cylindrical bluff body. By systematically tuning the inclination angle and installation position, the device achieves substantial performance improvements. Experimental results indicate that the optimized configuration yields a wider operational frequency band and enhanced energy conversion efficiency. Through the experimental results, we discovered the existence of the double-peak phenomenon and the plateau phenomenon. The voltage value of the second peak can reach up to 122.4% of the maximum voltage of the first peak. The duration of the maximum plateau phase can maintain between the wind speed of 2.3 m/s and 5.7 m/s. Full article

(This article belongs to the Special Issue Micro Energy Harvesting Systems: From Devices to Self-Powered Applications)

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23 pages, 5045 KB

Open AccessArticle

A Wearable Multi-Modal Measurement System with Self-Developed IMUs and Plantar Pressure Sensors for Real-Time Gait Recognition

by Xiuyu Li, Yunong Gao, Guanzhong Chen, Meiyan Zhang, Jingxiao Liao, Zhaoyun Wang and Jinwei Sun

Micromachines 2026, 17(3), 371; https://doi.org/10.3390/mi17030371 - 19 Mar 2026

Viewed by 423

Abstract

To address the limitations of existing wearable gait recognition, such as drift in static actions and difficulty in recognizing transition states, this paper proposed a gait recognition system based on the data fusion of MEMS Inertial Measurement Units (IMUs) and flexible plantar pressure [...] Read more.

To address the limitations of existing wearable gait recognition, such as drift in static actions and difficulty in recognizing transition states, this paper proposed a gait recognition system based on the data fusion of MEMS Inertial Measurement Units (IMUs) and flexible plantar pressure sensors. A low-power wearable device comprising four inertial and two pressure sensing nodes was developed to achieve synchronized multi-source data collection. Regarding the algorithm, a sensor-characteristic-based two-stage hierarchical framework was constructed. The first stage utilized plantar pressure features to efficiently decouple static postures from dynamic gaits. The second stage employed a lightweight Support Vector Machine combined with a Finite State Machine for static and transitional actions, while an ensemble learning model based on Soft Voting was used for complex dynamic gaits. Experimental results under Leave-One-Out Cross-Validation demonstrate a comprehensive recognition accuracy of 96.17%, with 100% accuracy for standing and 97% for sit-to-stand transitions. These findings validate the significant advantages of the multi-modal fusion approach in enhancing the robustness and generalization capabilities of gait recognition. Full article

(This article belongs to the Special Issue Flexible and Wearable Electronics for Biomedical Applications)

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20 pages, 4133 KB

Open AccessArticle

Co-Design of BW-Enhanced Dual-Path Driver and Segmented Microring Modulator for Energy Efficient Si-Photonic Transmitters

by Yingjie Ma, Bolun Cui, Guike Li, Jian Liu, Nanjian Wu, Nan Qi and Liyuan Liu

Micromachines 2026, 17(3), 370; https://doi.org/10.3390/mi17030370 - 19 Mar 2026

Viewed by 405

Abstract

Artificial intelligence computing systems increasingly demand high-bandwidth, high-extinction-ratio, chip-to-chip optical transceivers. Silicon microring modulators (MRMs) are attractive for such transmitters due to their compact footprint and wavelength-division multiplexing capability. However, for a specified extinction ratio, the optical bandwidth for high-Q MRMs and the [...] Read more.

Artificial intelligence computing systems increasingly demand high-bandwidth, high-extinction-ratio, chip-to-chip optical transceivers. Silicon microring modulators (MRMs) are attractive for such transmitters due to their compact footprint and wavelength-division multiplexing capability. However, for a specified extinction ratio, the optical bandwidth for high-Q MRMs and the driver’s RC time constant prevent conventional single-segment MRM drivers from supporting 100 GBaud class PAM4 transmission. This work presents a broadband driver exploiting the feedforward technique for dual-segment MRMs. It extends electro-optical bandwidth while maintaining a high Q-factor and extinction ratio. The input signal is split into low- and high-frequency components that drive the long and short segments of the MRM, respectively. The long segment uses a broadband low-pass driver, whereas the short segment employs a driver with a programmable bandpass response near the Nyquist frequency. The design space is obtained from an equivalent electro-optical model under constant group-delay constraints. Simulations at 1310 nm show that the 3 dB electro-optical bandwidth improves from ~50 to >70 GHz and that a 200 Gb/s PAM4 optical eye diagram exhibits an open eye; the energy efficiency is 1.44 pJ/bit, and the extinction ratio improves from 2 dB to 4.1 dB. The proposed technique provides a tunable electro-optical co-design approach for high-bandwidth-density, high-extinction-ratio silicon photonic transmitters. Full article

(This article belongs to the Special Issue Advances in Optoelectronic Co-Design: Bridging EIC and PIC Technologies)

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18 pages, 4043 KB

Open AccessArticle

Smart Biodegradable Nanosystems with Auxetic Metamaterial Shells and Thermosensitive Dynamic Covalent Bonds: Ultra-Slow Controlled Release and Theoretically Minimized Leakage

by Li Tao, Haoliang Zhang, Jiale Wu, Teng Zhang, Lei Shao, Litao Liu and Tianyu Chen

Micromachines 2026, 17(3), 369; https://doi.org/10.3390/mi17030369 - 19 Mar 2026

Viewed by 300

Abstract

Precise drug delivery remains a critical challenge in nanomedicine, with conventional nanocarriers suffering from significant drug leakage during circulation, limited control over release kinetics, and a lack of temporal control. This study presents a computational design and multiphysics simulation of a Smart Biodegradable [...] Read more.

Precise drug delivery remains a critical challenge in nanomedicine, with conventional nanocarriers suffering from significant drug leakage during circulation, limited control over release kinetics, and a lack of temporal control. This study presents a computational design and multiphysics simulation of a Smart Biodegradable Nanosystem. Through COMSOL Multiphysics simulations encompassing heat transfer, mass diffusion, and fluid dynamics, we validated the theoretical feasibility of a seven-layer architecture. The computational model predicts that mapping a re-entrant auxetic metamaterial topology onto a spherical scaffold enables geometric locking under fluidic stress, theoretically minimizing drug leakage. Furthermore, modeled thermosensitive dynamic covalent bonds demonstrate highly controlled release kinetics. All performance metrics presented herein are derived from predictive mathematical modeling. Theoretical degradation profiles indicate complete breakdown within 90–180 days into endogenous substances. This simulation-based study establishes a rigorous theoretical blueprint to guide future empirical fabrication in precision nanomedicine. Full article

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11 pages, 2304 KB

Open AccessArticle

Fabrication of Terahertz Fresnel Zone Plates via Ultraprecision Mechanical Processing

by Meng Chen, Jinshi Wang and Fengzhou Fang

Micromachines 2026, 17(3), 368; https://doi.org/10.3390/mi17030368 - 19 Mar 2026

Viewed by 272

Abstract

This study proposes a new fabrication process for terahertz Fresnel zone plates on high-resistivity silicon substrates. It involves ion implantation surface modification, ultra-precision diamond turning, and magnetron sputtering, followed by polishing. Ductile-regime cutting is used to form smooth microgrooves, which are selectively metallized [...] Read more.

This study proposes a new fabrication process for terahertz Fresnel zone plates on high-resistivity silicon substrates. It involves ion implantation surface modification, ultra-precision diamond turning, and magnetron sputtering, followed by polishing. Ductile-regime cutting is used to form smooth microgrooves, which are selectively metallized to create alternating opaque and transparent zones for terahertz waves. Finite-element simulations are performed to design the zone structure and to evaluate the effect of process-induced radius errors. A 3 μm amorphous layer is formed via ion implantation, which significantly enhances the ductile-to-brittle transition depth of silicon from 55 nm to about 535 nm while causing only minor changes in terahertz transmittance. The results demonstrate that the proposed method can produce high-quality Fresnel zone plates on silicon and offers a practical route to compact diffractive terahertz components. Full article

(This article belongs to the Special Issue Research Progress of Ultra-Precision Micro-Nano Machining, Second Edition)

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21 pages, 4667 KB

Open AccessArticle

MM-WAE: Multimodal Wasserstein Autoencoders for Semi-Supervised Wafer Map Defect Recognition

by Yifeng Zhang, Qingqing Sun, Ziyu Liu and David Wei Zhang

Micromachines 2026, 17(3), 367; https://doi.org/10.3390/mi17030367 - 18 Mar 2026

Viewed by 252

Abstract

Wafer map defect pattern recognition is a key task for ensuring yield in integrated circuit manufacturing. However, in real production lines it commonly suffers from scarce labeled data, long-tailed class distributions, and limited feature representations, which cause existing deep learning models to degrade [...] Read more.

Wafer map defect pattern recognition is a key task for ensuring yield in integrated circuit manufacturing. However, in real production lines it commonly suffers from scarce labeled data, long-tailed class distributions, and limited feature representations, which cause existing deep learning models to degrade in performance, particularly for minority defect classes and complex defect morphologies. To address these challenges, we propose a semi-supervised classification method for wafer maps based on a multimodal Wasserstein autoencoder (MM-WAE). The framework constructs three parallel feature branches in the spatial, frequency, and texture domains, using a multi-head attention mechanism and gating mechanism for adaptive multimodal fusion. This allows defect patterns to be comprehensively characterized by macroscopic geometric distributions, spectral periodic structures, and microscopic texture details. The Wasserstein autoencoder is introduced, with the latent space distribution regularized by a maximum mean discrepancy (MMD) loss using an inverse multiquadratic kernel. Additionally, an inverse class-frequency weighted cross-entropy loss and a modality consistency loss between the encoder and classifier jointly optimize the reconstruction and classification paths while leveraging large amounts of unlabeled wafer maps for semi-supervised learning. Experimental results show that MM-WAE mitigates performance limitations caused by insufficient labels and class imbalance, significantly improving the accuracy and robustness of wafer defect classification, with promising potential for industrial application and further development. Full article

(This article belongs to the Section E：Engineering and Technology)

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24 pages, 4536 KB

Open AccessReview

Recent Progress in Gain Materials for Microlasers and Modern Digital Approaches for Biophotonics: From Dyes to Semiconductors

by Carlos A. Calles-Arriaga, Romeo Selvas-Aguilar, Arturo A. Castillo-Guzmán, Wilian J. Pech-Rodríguez, Enrique Rocha-Rangel, María T. Maldonado-Sada, José A. Rodríguez-García, José A. Castillo-Robles and Eddie N. Armendáriz-Mireles

Micromachines 2026, 17(3), 366; https://doi.org/10.3390/mi17030366 - 18 Mar 2026

Viewed by 380

Abstract

Microlasers are innovative photonics devices that have recently attracted attention for their unique characteristics, including compactness, broad spectral emission, and low lasing threshold. These properties are beneficial in biophotonics as these lasers can interact with biological materials without causing damage, especially for optical [...] Read more.

Microlasers are innovative photonics devices that have recently attracted attention for their unique characteristics, including compactness, broad spectral emission, and low lasing threshold. These properties are beneficial in biophotonics as these lasers can interact with biological materials without causing damage, especially for optical biosensing applications. Among the optical materials recently used as gain media in microlasers are organic dyes, rare-earth ions, fluorescent proteins, and semiconductors, including quantum dots and perovskites. Moreover, different optical cavities and current laser configurations have increased the versatility of microlasers. Recently, digital sensing methods based on novel algorithms, machine learning, and neural networks have been combined with microlaser systems to enhance their accuracy and expand their applications. This work provides a comprehensive review of recent progress in microlasers, covering gain media, microcavity types, and their applications in biophotonics, including conventional spectral-based sensing and new digital approaches for the biomedical field. Full article

(This article belongs to the Section B：Biology and Biomedicine)

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11 pages, 3466 KB

Open AccessArticle

A High-Performance Film for Detecting Malachite Green

by Jiao Yang, Liqin Cui, Yibo Zhao and Xiaoping Wu

Micromachines 2026, 17(3), 365; https://doi.org/10.3390/mi17030365 - 18 Mar 2026

Viewed by 262

Abstract

The residual malachite green (MG) in aquatic products poses a severe threat to human health, thus an urgent need exists for the establishment of a rapid and accurate analytical method. In this work, a high-performance film based on a nano-network structure was developed [...] Read more.

The residual malachite green (MG) in aquatic products poses a severe threat to human health, thus an urgent need exists for the establishment of a rapid and accurate analytical method. In this work, a high-performance film based on a nano-network structure was developed for the highly sensitive detection of MG. This film employed the nanonetwork structure as its sensing substrate, and the network structure with a high specific surface area enabled efficient enrichment of MG molecules. The silver nanoparticles uniformly modified on the surface could produce a remarkable localized surface plasmon resonance effect, thereby significantly enhancing the signals of MG molecules adsorbed on its surface. The results showed that the film exhibited a low limit of detection (LOD) of 8.8 pM for MG, with a linear range from 10 to 5000 pM. In the detection of aquatic products, this film successfully achieved the rapid and accurate determination of MG in aquatic products, showing an excellent potential for practical applications. The nanonetwork-structured film developed in this work provides a reliable and sensitive technical solution for the trace detection of MG in aquatic products. Full article

(This article belongs to the Special Issue Advanced Micro-Nano Optical Sensors Based on MOEMS Technologies)

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10 pages, 1489 KB

Open AccessArticle

Investigation of Resistive Switching in Cu/a-SiC/P⁺-Si Structure for Multilevel Nonvolatile Memory Applications

by Hehong Shao, Xiuwei Zhu, Xin Zhang, Wanting Zheng, Libing Zhang and Liangliang Chen

Micromachines 2026, 17(3), 364; https://doi.org/10.3390/mi17030364 - 17 Mar 2026

Viewed by 236

Abstract

Here, the resistive switching characteristics in a Cu/a-SiC/P+-Si sandwiched structure are systematically investigated for multilevel nonvolatile memory applications. The formation of Cu conducting filaments is believed to be the switching mechanism through temperature-dependent testing. Four distinguished resistance states can be achieved in the [...] Read more.

Here, the resistive switching characteristics in a Cu/a-SiC/P+-Si sandwiched structure are systematically investigated for multilevel nonvolatile memory applications. The formation of Cu conducting filaments is believed to be the switching mechanism through temperature-dependent testing. Four distinguished resistance states can be achieved in the Cu/a-SiC/P+-Si memory device through the modulation of suitable compliance current, which could be attributed to the formation of more conductive filaments when applying a higher compliance current during the Set process. In addition, these different resistance values can be easily distinguished and show reliable retention (~105 s), with the temperature even reaching 85 °C, which offers considerable potential for high-density RRAM applications. Full article

(This article belongs to the Special Issue State-of-the-Art Memristor and Optoelectronic Memristor: Materials, Fabrication, Mechanism and Applications)

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15 pages, 5707 KB

Open AccessArticle

Highly Sensitive Control Study of PD Archimedean Antenna Based on Rotating Unit Reflective Metasurface

by Lihao Luo, Junlin Gai, Dapeng Han, Minghan Ke, Haonan Zhang, Zhenhao Huang and Guozhi Zhang

Micromachines 2026, 17(3), 363; https://doi.org/10.3390/mi17030363 - 17 Mar 2026

Viewed by 228

Abstract

Addressing the insufficient sensitivity of typical Archimedean spiral antennas for detecting partial discharge (PD) in electrical equipment, this paper proposes a high-sensitivity regulation technique for PD Archimedean antennas based on rotating unit-cell reflective metasurfaces. First, a finite element model of the ultra-high-frequency Archimedean [...] Read more.

Addressing the insufficient sensitivity of typical Archimedean spiral antennas for detecting partial discharge (PD) in electrical equipment, this paper proposes a high-sensitivity regulation technique for PD Archimedean antennas based on rotating unit-cell reflective metasurfaces. First, a finite element model of the ultra-high-frequency Archimedean antenna was constructed. Then, employing metasurface electromagnetic wave reflection technology and phase compensation principles, a rotating-unit reflective metasurface was designed to optimize its full-bandwidth gain. A multi-parameter joint optimization method was used to obtain the optimal data for the antenna and metasurface parameters. Finally, simulations and experimental analyses of the super-surface-controlled Archimedean antenna revealed the following: The gain of the Archimedean antenna controlled by the rotating-unit super-surface increases by up to 15.61 dB in the 0.3–1.5 GHz band, with an average full-band gain enhancement of 3.42 dB. During electrostatic discharge (ESD), the amplitude of UHF signals detected by the Archimedean antenna increases by approximately 88.9%, and the amplitude detection of UHF signals during GIS discharges increases by approximately 138.6–150%. These results demonstrate that the metasurface significantly enhances the antenna’s gain performance, providing a reference for highly sensitive control technologies in detecting discharges in electrical equipment. Full article

(This article belongs to the Special Issue Electromagnetic Metamaterials and Metasurfaces: From Design to Applications)

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16 pages, 1823 KB

Open AccessArticle

Isolation of Exosomes from MDA-MB-231 Cells Using a Paddle Screw System and Detection of TNBC-Associated Exosomal miRNAs

by Han Sol Kim and Soo Suk Lee

Micromachines 2026, 17(3), 362; https://doi.org/10.3390/mi17030362 - 16 Mar 2026

Viewed by 359

Abstract

Exosomes are nanoscale extracellular vesicles that carry disease-associated microRNAs (miRNAs) and represent promising biomarkers for cancer diagnosis. Triple-negative breast cancer (TNBC) lacks well-defined molecular markers, necessitating sensitive and integrable analytical approaches for TNBC-related exosomal miRNAs. In this study, exosomes were isolated from MDA-MB-231 [...] Read more.

Exosomes are nanoscale extracellular vesicles that carry disease-associated microRNAs (miRNAs) and represent promising biomarkers for cancer diagnosis. Triple-negative breast cancer (TNBC) lacks well-defined molecular markers, necessitating sensitive and integrable analytical approaches for TNBC-related exosomal miRNAs. In this study, exosomes were isolated from MDA-MB-231 TNBC cells using a paddle screw-based system designed to enhance mass transfer through active rotation, providing a mechanically driven isolation strategy that is compatible with miniaturized and microfluidic platforms. This dynamic isolation process enabled rapid and efficient exosome recovery within a short processing time. Three TNBC-associated miRNAs encapsulated in the isolated exosomes were quantitatively analyzed using polyadenylation tailing (poly(A) tailing) and specific bidirectional extension sequence-based assays combined with reverse transcription quantitative real-time PCR (RT-qPCR). The bidirectional extension (BDE) assay generated highly specific PCR templates, leading to improved amplification specificity and reduced background signals. The RT-qPCR analysis exhibited high sensitivity, wide dynamic range, and good reproducibility for all target miRNAs. Overall, these results demonstrate that the integration of a paddle screw-based exosome isolation module with an extension-based nucleic acid detection strategy provides a scalable and biosensor-compatible analytical framework for profiling TNBC-associated exosomal miRNAs, with potential applications in microfluidic liquid biopsy platforms and exosome-based cancer diagnostics. Full article

(This article belongs to the Special Issue Biosensors for Biomedical, Agricultural and Environmental Applications)

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28 pages, 10705 KB

Open AccessReview

A Review of the Machining Mechanisms in Field-Assisted Cutting of Brittle Materials

by Xuexiang Sheng, Zhanchen Zhu and Changlin Liu

Micromachines 2026, 17(3), 361; https://doi.org/10.3390/mi17030361 - 15 Mar 2026

Cited by 1 | Viewed by 358

Abstract

Brittle materials such as single crystals, polycrystalline ceramics, and amorphous glass are indispensable in modern industry. Driven by improvements in equipment performance, the required fabrication precision for optical elements and devices has reached nanoscale and is steadily advancing toward atomic level. Despite their [...] Read more.

Brittle materials such as single crystals, polycrystalline ceramics, and amorphous glass are indispensable in modern industry. Driven by improvements in equipment performance, the required fabrication precision for optical elements and devices has reached nanoscale and is steadily advancing toward atomic level. Despite their outstanding physical and chemical properties, fabricating a defect-free surface with nanometer-level roughness on brittle materials is challenging due to microcracking, brittle fracture and severe tool wear. In recent years, field-assisted cutting has emerged to overcome the bottleneck in ultra-precision cutting of brittle materials. This review summarizes investigations of material removal mechanisms of brittle materials in ultra-precision cutting and surveys representative field-assisted cutting technologies—including laser, vibration, magnetic field, and ion implantation assisted cutting—highlighting how these fields broaden ductile-regime machining and suppress the machining-induced defects. This review further discusses the emerging multi-field coupling strategies and outlines future research directions in machining mechanisms to enable high-efficiency, low-damage, and high-consistency manufacturing of brittle materials. Full article

(This article belongs to the Special Issue Future Trends in Ultra-Precision Machining)

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17 pages, 9582 KB

Open AccessArticle

Fabrication of Wear-Resistant and Anti-Reflection Surfaces Based on Armor-Protected Nanocone Structures

by Haoyu Tian, Jianxun Chen, Jiaheng Bi, Haotian Guo, Cheng Lei and Ruirui Li

Micromachines 2026, 17(3), 360; https://doi.org/10.3390/mi17030360 - 15 Mar 2026

Viewed by 272

Abstract

Antireflection surfaces play an indispensable role in modern optics, with extensive applications covering optical windows and other precision optical components. The fabrication of anti-reflection surfaces frequently relies on micro/nano-structuring technologies. However, the fabricated micro/nanostructures typically experience performance degradation in transmission enhancement caused by [...] Read more.

Antireflection surfaces play an indispensable role in modern optics, with extensive applications covering optical windows and other precision optical components. The fabrication of anti-reflection surfaces frequently relies on micro/nano-structuring technologies. However, the fabricated micro/nanostructures typically experience performance degradation in transmission enhancement caused by abrasion during operation. To address this problem, we designed and fabricated a double-sided nanocone structure shielded by a protective armor layer. This armor layer efficiently prevents surface mechanical wear and preserves the nanocone structures, leading to almost constant transmittance of the anti-reflection surface even after abrasion. The anti-reflection surface was fabricated by first patterning a square grid armor on one side of fused silica via photolithography, followed by the preparation of an etching mask and nanocone structures using reactive ion etching (RIE). Nanocones were then fabricated on the opposite side of the substrate, finally forming the double-sided nanocone structure. The fabricated armor-protected double-sided nanocone structure exhibited an increase in the average transmittance from 93.43% to 98.31% within the wavelength range of 800–1200 nm. After abrasion testing under 10 MPa pressure, the nanocones under the protective armor showed almost no damage, and the average transmittance remained at approximately 97.85%, demonstrating the outstanding mechanical robustness of the proposed design. Full article

(This article belongs to the Special Issue Micro/Nanomanufacturing and Cross-Scale Fabrication: Methods, Systems, and Applications)

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Micromachines, Volume 17, Issue 3 (March 2026) – 114 articles

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