Micromachines最新文献

{"title":"Application of Carbon Nanotube-Based Elastomeric Matrix for Capacitive Sensing in Diabetic Foot Orthotics.","authors":"Monisha Elumalai, Andre Childs, Samantha Williams, Gabriel Arguello, Emily Martinez, Alaina Easterling, Dawn San Luis, Swaminathan Rajaraman, Charles M Didier","doi":"10.3390/mi16070804","DOIUrl":"10.3390/mi16070804","url":null,"abstract":"<p><p>Diabetic foot ulcers (DFUs) represent a critical global health issue, necessitating the development of advanced smart, flexible, and wearable sensors for continuous monitoring that are reimbursable within foot orthotics. This study presents the design and characterization of a pressure sensor implemented into a shoe insole to monitor diabetic wound pressures, emphasizing the need for a high sensitivity, durability under cyclic mechanical loading, and a rapid response time. This investigation focuses on the electrical and mechanical properties of carbon nanotube (CNT) composites utilizing Ecoflex and polydimethylsiloxane (PDMS). Morphological characterization was conducted using Transmission Electron Microscopy (TEM), Laser Confocal Microscopy, and Scanning Electron Microscopy (SEM). The electrical and mechanical properties of the CNT/Ecoflex- and the CNT/PDMS-based sensor composites were then investigated. CNT/Ecoflex was then further evaluated due to its lower variability performance between cycles at the same pressure, as well as its consistently higher capacitance values across all trials in comparison to CNT/PDMS. The CNT/Ecoflex composite sensor showed a high sensitivity (2.38 to 3.40 kPa^-1) over a pressure sensing range of 0 to 68.95 kPa. The sensor's stability was further assessed under applied pressures simulating human weight. A custom insole prototype, incorporating 12 CNT/Ecoflex elastomeric matrix-based sensors (as an example) distributed across the metatarsal heads, midfoot, and heel regions, was developed and characterized. Capacitance measurements, ranging from 0.25 pF to 60 pF, were obtained across N = 3 feasibility trials, demonstrating the sensor's response to varying pressure conditions linked to different body weights. These results highlight the potential of this flexible insole prototype for precise and real-time plantar surface monitoring, offering an approachable avenue for a challenging diabetic orthotics application.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12300393/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742748","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":"Numerical Investigation of Mixing Performance in Microfluidic Chip via Structural Micro-Rotors.","authors":"Yongliang Dong, Liqiu Wang, Xing Han","doi":"10.3390/mi16070806","DOIUrl":"10.3390/mi16070806","url":null,"abstract":"<p><p>Microfluidics is a powerful tool with extensive applications, including chemical synthesis and biological detection. However, the limited channel size and high viscosity of samples/reagents make it difficult to fully mix liquids and improve the reaction efficiency inside microfluidic chips. Active mixing by rotors has been proven to be an effective method to promote mixing efficiency via a magnetic field. Here, we numerically investigated the mixing performance of rotors with different shapes (bar-shaped, Y-shaped, and cross-shaped). We systematically studied the influence of the arrangement of multiple cross-rotors and the rotation rate on mixing performance. The results are promising for instructing the design and manipulation of rotors for in-channel mixing.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12298049/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742714","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":"Integrated CAD/CAM Approach for Parametric Design and High Precision Fabrication of Planar Curvilinear Structures.","authors":"Jonas T Churchill-Baird, O Remus Tutunea-Fatan, Evgueni V Bordatchev","doi":"10.3390/mi16070805","DOIUrl":"10.3390/mi16070805","url":null,"abstract":"<p><p>Curvilinear V-grooves are increasingly employed in functional surfaces with applications ranging from fluidics to tribology and optics. Despite their widespread use, the accurate and repeatable fabrication of curvilinear V-grooves remains challenging due to their inherent geometric complexity and the lack of relevant commercial CAD/CAM systems. To address this, the present study proposes a CAD/CAM integrated framework capable of automating the design and fabrication of functional surfaces comprising curvilinear V-grooves generated by multi-axis single-point diamond cutting (SPDC). The framework is organized into three main functional blocks supported by seven secondary modules that encompass the entire process from V-groove geometry definition to cutting. The developed framework was practically validated by fabricating sinusoidal V-grooves on a flat surface and testing the capillary flow functionality of a curvilinear pattern. These results demonstrate the relevance of the integrated framework to curvilinear V-groove fabrication, thereby offering a versatile solution for certain types of surface engineering applications.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12299821/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742764","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":"The Impact of Acoustic Synthetic Jet Actuator Parameters on the Generated Noise.","authors":"Emil Smyk, Michał Stopel","doi":"10.3390/mi16070803","DOIUrl":"10.3390/mi16070803","url":null,"abstract":"<p><p>Synthetic jet actuators are becoming increasingly popular for enhancing electronic heat transfer. However, their use is currently limited due to the high noise they generate. This article examines how actuator parameters (orifice diameter, orifice length and cavity height) affect synthetic jet velocity and noise generation. Hot-wire anemometry was used to measure velocity, and noise was measured with a sound meter. The actuator was supplied with constant power at different frequencies ranging from 50 to 500 Hz. Observation of the velocity showed that it decreased with an increasing orifice diameter and increased with a decreasing orifice length. No relationship was observed between cavity height and synthetic jet velocity. This article indicates that increasing the orifice diameter or reducing the orifice length causes an increase in the noise generated by SJAs, provided we remain in the vicinity of the characteristic frequency. It was demonstrated that higher actuator chambers produce higher noise levels, although this was not a consistent trend across the entire tested frequency range.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12298604/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742803","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":"Overcoming Challenges in Silicon Anodes: The Role of Electrolyte Additives and Solid-State Electrolytes.","authors":"Jinsik Nam, Hanbyeol Lee, Oh B Chae","doi":"10.3390/mi16070800","DOIUrl":"10.3390/mi16070800","url":null,"abstract":"<p><p>Silicon-based anodes have emerged as promising candidates for advanced lithium-ion batteries (LIBs) owing to their outstanding lithium storage capacity; however, the commercial implementation of silicon-based anodes is hindered primarily by their significant volumetric changes and the resulting solid electrolyte interphase (SEI) instability during the lithiation/delithiation process. To overcome these issues, electrolyte optimization, particularly through the use of functional additives and solid-state electrolytes, has attracted significant research attention. In this paper, we review the recent developments in electrolyte additives, such as vinylene carbonate, fluoroethylene carbonate, and silane-based additives, and new additives, such as dimethylacetamide, that improve the SEI stability and overall electrochemical performance of silicon-based anodes. We also discuss the role of solid electrolytes, including oxides, sulfides, and polymer-based systems, in mitigating the volume changes in Si and improving safety. Such approaches can effectively enhance both the longevity and capacity retention of silicon-based anodes. Despite significant progress, further studies are essential to optimize electrolyte formulation and solve interfacial problems. Integrating these advances with improved electrode designs and anode materials is critical for realizing the full potential of silicon-based anodes in high-performance LIBs, particularly in electric vehicles and portable electronics.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12300681/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742720","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":"Comparative Noise Analysis of Readout Circuit in Hemispherical Resonator Gyroscope.","authors":"Zhihao Yu, Libin Zeng, Changda Xing, Lituo Shang, Xiuyue Yan, Jingyu Li","doi":"10.3390/mi16070802","DOIUrl":"10.3390/mi16070802","url":null,"abstract":"<p><p>In high-precision Hemispherical Resonator Gyroscope (HRG) control systems, readout circuit noise critically determines resonator displacement detection precision. Addressing noise issues, this paper compares the noise characteristics and contribution mechanisms of the Transimpedance Amplifier (TIA) and Charge-Sensitive Amplifier (CSA). By establishing a noise model and analyzing circuit bandwidth, the dominant role of feedback resistor thermal noise in the TIA is revealed. These analyses further demonstrate the significant suppression of high-frequency noise by the CSA capacitive feedback network. Simulation and experimental results demonstrate that the measured noise of the TIA and CSA is consistent with the theoretical model. The TIA output noise is 25.8 μVrms, with feedback resistor thermal noise accounting for 99.8%, while CSA output noise is reduced to 13.2 μVrms, a reduction of 48.8%. Near resonant frequency, the equivalent displacement noise of the CSA is 1.69×10-14m/Hz, a reduction of 86.7% compared to the TIA's 1.27×10-13m/Hz, indicating the CSA is more suitable for high-precision applications. This research provides theoretical guidance and technical references for the topological selection and parameter design of HRG readout circuits.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12299202/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742679","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":"An Enhanced Circularly Polarized Textile Antenna Using a Metasurface and Slot-Patterned Ground for Off-Body Communications.","authors":"Yong-Deok Kim, Tu Tuan Le, Tae-Yeoul Yun","doi":"10.3390/mi16070799","DOIUrl":"10.3390/mi16070799","url":null,"abstract":"<p><p>This paper presents an enhanced circularly polarized (CP) all-textile antenna using a metasurface (MS) and slot-patterned ground (SPG) for 5.8 GHz industry, scientific, and medical (ISM)-band applications in off-body communications. The 3 × 3 MS, capable of converting the incident wave into an orthogonal direction with equal magnitude and a 90° phase difference, converts the linearly polarized (LP) wave, radiated from the fundamental radiator with a corner-truncated slot square-patch configuration, into being CP. The SPG, consisting of periodic slots with two different sizes of corner-truncated slots, redistributes the surface current on the ground plane, enhancing the axial ratio bandwidth (ARBW) of the proposed antenna. The novel combination of MS and SPG not only enables the generation and enhancement of CP characteristics but also significantly improves the impedance bandwidth (IBW), gain, and radiation efficiency by introducing additional surface wave resonances. The proposed antenna is composed of a conductive textile and a felt substrate, offering comfort and flexibility for applications where the antenna is placed in close proximity to the human body. The proposed antenna is simulated under bending in various directions, showing exceptionally similar characteristics to a flat condition. The proposed antenna is fabricated and is then verified by measurements in both free space and a human body environment. The measured IBW is 36.3%, while the ARBW is 18%. The measured gain and radiation efficiency are 6.39 dBic and 64.7%, respectively. The specific absorption rate (SAR) is simulated, and the results satisfy both US and EU safety standards.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12301038/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742741","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":"Constant High-Voltage Triboelectric Nanogenerator with Stable AC for Sustainable Energy Harvesting.","authors":"Aso Ali Abdalmohammed Shateri, Salar K Fatah, Fengling Zhuo, Nazifi Sani Shuaibu, Chuanrui Chen, Rui Wan, Xiaozhi Wang","doi":"10.3390/mi16070801","DOIUrl":"10.3390/mi16070801","url":null,"abstract":"<p><p>Triboelectric nanogenerators (TENGs) hold significant potential for decentralized energy harvesting; however, their dependence on rotational mechanical energy often limits their ability to harness ubiquitous horizontal motion in real-world applications. Here, a single horizontal linear-to-rotational triboelectric nanogenerator (SHLR-TENG) is presented, designed to efficiently convert linear motion into rotational energy using a robust gear system, enabling a high voltage and reliable full cycle of alternating current (AC). The device features a radially patterned disk with triboelectric layers composed of polyimide. The SHLR-TENG achieves a peak-to-peak voltage of 1420 V, a short-circuit current of 117 µA, and an average power output of 41.5 mW, with a surface charge density of 110 µC/m². Moreover, it demonstrates a power density per unit volume of 371.2 W·m^-3·Hz^-1. The device retains 80% efficiency after 1.5 million cycles, demonstrating substantial durability under mechanical stress. These properties enable the SHLR-TENG to directly power commercial LEDs and low-power circuits without the need for energy storage. This study presents an innovative approach to sustainable energy generation by integrating horizontal motion harvesting with rotational energy conversion. The compact and scalable design of the SHLR-TENG, coupled with its resilience to humidity (20-90% RH) and temperature fluctuations (10-70 °C), positions it as a promising next-generation energy source for Internet of Things (IoT) devices and autonomous systems.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12299868/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742680","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":"Design and Fabrication of Multi-Frequency and Low-Quality-Factor Capacitive Micromachined Ultrasonic Transducers.","authors":"Amirhossein Moshrefi, Abid Ali, Mathieu Gratuze, Frederic Nabki","doi":"10.3390/mi16070797","DOIUrl":"10.3390/mi16070797","url":null,"abstract":"<p><p>Capacitive micromachined ultrasonic transducers (CMUTs) have been developed for air-coupled applications to address key challenges such as noise, prolonged ringing, and side-lobe interference. This study introduces an optimized CMUT design that leverages the squeeze-film damping effect to achieve a low-quality factor, enhancing resolution and temporal precision for imaging as one of the suggested airborne application. The device was fabricated using the PolyMUMPs process, ensuring high structural accuracy and consistency. Finite element analysis (FEA) simulations validated the optimized parameters, demonstrating improved displacement, reduced side-lobe artifacts, and sharper main lobes for superior imaging performance. Experimental validation, including Laser Doppler Vibrometer (LDV) measurements of membrane displacement and mode shapes, along with ring oscillation tests to assess Q-factor and signal decay, confirmed the device's reliability and consistency across four CMUT arrays. Additionally, this study explores the implementation of multi-frequency CMUT arrays, enhancing imaging versatility across different air-coupled applications. By integrating multiple frequency bands, the proposed CMUTs enable adaptable imaging focus, improving their suitability for diverse diagnostic scenarios. These advancements highlight the potential of the proposed design to deliver a superior performance for airborne applications, paving the way for its integration into advanced diagnostic systems.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12299860/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Hierarchical Inverse Lithography Method Considering the Optimization and Manufacturability Limit by Gradient Descent.","authors":"Haifeng Sun, Qingyan Zhang, Jie Zhou, Jianwen Gong, Chuan Jin, Ji Zhou, Junbo Liu","doi":"10.3390/mi16070798","DOIUrl":"10.3390/mi16070798","url":null,"abstract":"<p><p>Inverse lithography technology (ILT) based on the gradient descent (GD) algorithm, which is a classical local optimal method, can effectively improve the lithographic imaging fidelity. However, due to the low-pass filtering effect of the lithography imaging system, GD, although able to converge quickly, is prone to fall into the local optimum for the information in the corner region of complex patterns. Considering the high-frequency information of the corner region during the optimization process, this paper proposes a resolution layering method to improve the efficiency of GD-based ILT algorithms. A corner-rounding-inspired target retargeting strategy is used to compensate for the over-optimization defect of GD for inversely optimizing the complex pattern layout. Furthermore, for ensuring the manufacturability of masks, differentiable top-hat and bottom-hat operations are employed to improve the optimization efficiency of the proposed method. To confirm the superiority of the proposed method, multiple optimization methods of ILT were compared. Numerical experiments show that the proposed method has higher optimization efficiency and effectively avoids the over-optimization.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 7","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12300207/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144742728","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}