Micromachines最新文献_第9页

Design and Testing of a Portable Wireless Multi-Node sEMG System for Synchronous Muscle Signal Acquisition and Gesture Recognition.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-27 DOI: 10.3390/mi16030279

Xiaoying Zhu, Chaoxin Li, Xiaoman Liu, Yao Tong, Chang Liu, Kai Guo

{"title":"Design and Testing of a Portable Wireless Multi-Node sEMG System for Synchronous Muscle Signal Acquisition and Gesture Recognition.","authors":"Xiaoying Zhu, Chaoxin Li, Xiaoman Liu, Yao Tong, Chang Liu, Kai Guo","doi":"10.3390/mi16030279","DOIUrl":"10.3390/mi16030279","url":null,"abstract":"Surface electromyography (sEMG) is an important non-invasive method used in muscle function assessment, rehabilitation and human-machine interaction. However, existing commercial devices often lack sufficient channels, making it challenging to simultaneously acquire signals from multiple muscle sites.In this acticle, we design a portable multi-node sEMG acquisition system based on the TCP protocol to overcome the channel limitations of commercial sEMG detection devices. The system employs the STM32L442KCU6 microcontroller as the main control unit, with onboard ADC for analog-to-digital conversion of sEMG signals. Data filtered by analogy filter is transmitted via an ESP8266 WiFi module to the host computer for display and storage. By configuring Bluetooth broadcasting channels, the system can support up to 40 sEMG detection nodes. A gesture recognition algorithm is implemented to identify grasping motions with varying channel configurations. Experimental results demonstrate that with two channels, the Gradient Boosting Decision Tree (GBDT) algorithm achieves a recognition accuracy of 99.4%, effectively detecting grasping motions.","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944688/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720236","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}

引用次数: 0

An Electrochemical Immunosensor for Sensitive Detection of Exosomes Based on Au/MXenes and AuPtPdCu.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-27 DOI: 10.3390/mi16030280

Jie Gao, Rong Yang, Xiaorui Zhu, Jiling Shi, Sufei Wang, Aihua Jing

{"title":"An Electrochemical Immunosensor for Sensitive Detection of Exosomes Based on Au/MXenes and AuPtPdCu.","authors":"Jie Gao, Rong Yang, Xiaorui Zhu, Jiling Shi, Sufei Wang, Aihua Jing","doi":"10.3390/mi16030280","DOIUrl":"10.3390/mi16030280","url":null,"abstract":"Exosomes are important biomarkers for liquid biopsy in early cancer screening which play important roles in many biological processes, including apoptosis, inflammatory response, and tumor metastasis. In this study, an electrochemical aptamer immunosensor based on Au/MXene and AuPtPdCu was constructed for the sensitive detection of colorectal cancer-derived exosomes. AuNPs were deposited in situ on the surface of MXenes as a sensing platform due to their large specific area, excellent conductivity, and higher number of active sites for aptamer immobilization. The aptamer CD63 immobilized on Au/MXene can specifically capture target exosomes. Therefore, the AuPtPdCu-Apt nanoprobe further enhanced the sensitivity and accuracy of the immunosensor. A low limit of detection of 19 particles μL-1 was achieved in the linear range of 50 to 5 × 104 particles μL-1 under optimal conditions. The immunosensor developed herein showed satisfactory electrochemical stability and anti-interference ability for the detection of exosomes in real serum samples.","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944654/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720021","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}

引用次数: 0

Back Propagation Neural Network-Based Predictive Model for Magnetorheological-Chemical Polishing of Silicon Carbide.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-27 DOI: 10.3390/mi16030271

Huazhuo Liang, Wenjie Chen, Youzhi Fu, Wenjie Zhou, Ling Mo, Yue Jian, Qi Wen, Dawei Liu, Junfeng He

{"title":"Back Propagation Neural Network-Based Predictive Model for Magnetorheological-Chemical Polishing of Silicon Carbide.","authors":"Huazhuo Liang, Wenjie Chen, Youzhi Fu, Wenjie Zhou, Ling Mo, Yue Jian, Qi Wen, Dawei Liu, Junfeng He","doi":"10.3390/mi16030271","DOIUrl":"10.3390/mi16030271","url":null,"abstract":"Magnetorheological-chemical-polishing tests are carried out on single-crystal silicon carbide (SiC) to study the influence of the process parameters on the polishing effect, predict the polishing results via a back propagation (BP) neural network, and construct a model of the processing parameters to predict the material removal rate (MRR) and surface quality. Magnetorheological-chemical polishing employs mechanical removal coupled with chemical action, and the synergistic effect of both actions can achieve an improved polishing effect. The results show that with increasing abrasive particle size, hydrogen peroxide concentration, workpiece rotational speed, and polishing disc rotational speed, the MRR first increases and then decreases. With an increasing abrasive concentration and carbonyl iron powder concentration, the MRR continues to increase. With an increasing machining gap, the MRR shows a continuous decrease, and the corresponding changes in surface roughness tend to decrease first and then increase. The prediction models of the MRR and surface quality are constructed via a BP neural network, and their average absolute percentage errors are less than 2%, which is important for the online monitoring of processing and process optimisation.","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946469/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720207","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}

引用次数: 0

Applying Acoustic Signals to Monitor Hybrid Electrical Discharge-Turning with Artificial Neural Networks.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-27 DOI: 10.3390/mi16030274

Mehdi Soleymani, Mohammadjafar Hadad

{"title":"Applying Acoustic Signals to Monitor Hybrid Electrical Discharge-Turning with Artificial Neural Networks.","authors":"Mehdi Soleymani, Mohammadjafar Hadad","doi":"10.3390/mi16030274","DOIUrl":"10.3390/mi16030274","url":null,"abstract":"Artificial intelligence (AI) models have demonstrated their capabilities across various fields by performing tasks that are currently handled by humans. However, the training of these models faces several limitations, such as the need for sufficient data. This study proposes the use of acoustic signals as training data as this method offers a simpler way to obtain a large dataset compared to traditional approaches. Acoustic signals contain valuable information about the process behavior. We investigated the ability of extracting useful features from acoustic data expecting to predict labels separately by a multilabel classifier rather than as a multiclass classifier. This study focuses on electrical discharge turning (EDT) as a hybrid process of electrical discharge machining (EDM) and turning, an intricate process with multiple influencing parameters. The sounds generated during EDT were recorded and used as training data. The sounds underwent preprocessing to examine the effects of the parameters used for feature extraction prior to feeding the data into the ANN model. The parameters investigated included sample rate, length of the FFT window, hop length, and the number of mel-frequency cepstral coefficients (MFCC). The study aimed to determine the optimal preprocessing parameters considering the highest precision, recall, and F1 scores. The results revealed that instead of using the default set values in the python packages, it is necessary to investigate the preprocessing parameters to find the optimal values for the maximum classification performance. The promising results of the multi-label classification model depicted that it is possible to detect various aspects of a process simultaneously receiving single data, which is very beneficial in monitoring. The results also indicated that the highest prediction scores could be achieved by setting the sample rate, length of the FFT window, hop length, and number of MFCC to 4500 Hz, 1024, 256, and 80, respectively.","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944751/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143719978","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}

引用次数: 0

Design and Simulation of Magnetic Shielding Structure Based on Closed-Loop TMR Current Sensor.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-27 DOI: 10.3390/mi16030272

Qiuyang Li, Suqin Xiong, Shuo Wang, Xianguang Dong, Haifeng Zhang

{"title":"Design and Simulation of Magnetic Shielding Structure Based on Closed-Loop TMR Current Sensor.","authors":"Qiuyang Li, Suqin Xiong, Shuo Wang, Xianguang Dong, Haifeng Zhang","doi":"10.3390/mi16030272","DOIUrl":"10.3390/mi16030272","url":null,"abstract":"With the rapid development of current sensor technology, tunnel magnetoresistance (TMR) current sensors have been widely adopted in industrial detection due to their high sensitivity, excellent linearity, and broad measurement range. This study focuses on closed-loop TMR current sensors, utilizing COMSOL Multiphysics 6.2 software and the finite element method to conduct an in-depth analysis of structural parameters affecting sensor sensitivity. A novel magnetic shielding package architecture is proposed and designed. Simulation results demonstrate that the shielding efficiency of this structure improves by 44.3% compared to a single magnetic ring under a stray magnetic field of 0.1 mT along the sensing axis. At the same time, the measurement accuracy is 2.1 times higher than that of traditional structures. Current detection experiments conducted in a strong magnetic field environment further validate that the shielding package effectively suppresses external electromagnetic interference, significantly enhancing sensor stability and measurement accuracy. This research provides important theoretical and practical insights for applying high-precision TMR current sensors in complex electromagnetic environments.","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944719/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720232","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}

引用次数: 0

Progress in Polycrystalline SiC Growth by Low Pressure Chemical Vapor Deposition and Material Characterization.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-27 DOI: 10.3390/mi16030276

Michail Gavalas, Yann Gallou, Didier Chaussende, Elisabeth Blanquet, Frédéric Mercier, Konstantinos Zekentes

{"title":"Progress in Polycrystalline SiC Growth by Low Pressure Chemical Vapor Deposition and Material Characterization.","authors":"Michail Gavalas, Yann Gallou, Didier Chaussende, Elisabeth Blanquet, Frédéric Mercier, Konstantinos Zekentes","doi":"10.3390/mi16030276","DOIUrl":"10.3390/mi16030276","url":null,"abstract":"The purpose of this paper is to give a review on the state of the art of polycrystalline SiC material grown by low-pressure chemical vapor deposition (LPCVD). Nowadays, LPCVD is the main technique used for the deposition of polycrystalline SiC, both in academic research and industry. Indeed, the LPCVD technique is today the most mature technique to grow high purity polycrystalline thin films with controlled thickness and structure over a large area (>50 cm) and/or 3D substrate. Its ability to have a high degree of modification on the growth conditions and the chosen precursor system allows the deposition of polycrystalline SiC films in various substrates with tailored properties according to the desired application. After a short introduction on the SiC material and its growth by the LPCVD technique, a review of theoretical studies (thermodynamics and kinetics) related to the CVD SiC growth process is given. A synthesis of the experimental studies is made focusing on the effect of the growth conditions on the properties of the deposited SiC polycrystalline material. Despite the numerous results, a full understanding of them is limited due to the complexity of the LPCVD process and the polycrystalline SiC structure. The conclusions show that the growth conditions, like temperature, chamber pressure, (C/Si)(g), (Cl/Si)(g), and doping have an impact on the microstructure and on the corresponding properties of the polycrystalline SiC films. Future perspectives are given in order to improve our understanding on the polycrystalline-SiC-LPCVD process and to enable the growth of tailor-made polycrystalline SiC films for future applications.","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946532/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720340","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}

引用次数: 0

An Ion Discharge-Driven Thruster Based on a Lithium Niobate Piezoelectric Transformer.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-27 DOI: 10.3390/mi16030277

Qiannan Tao, Xinshuai Wang, Yang Gu, Wei Li

{"title":"An Ion Discharge-Driven Thruster Based on a Lithium Niobate Piezoelectric Transformer.","authors":"Qiannan Tao, Xinshuai Wang, Yang Gu, Wei Li","doi":"10.3390/mi16030277","DOIUrl":"10.3390/mi16030277","url":null,"abstract":"Microrobots, characterized by their small size, flexibility, and portability, have a diverse range of potential applications. However, microrobots' actuation (piezoelectric ceramics, dielectric elastomers, ion winds, etc.) often requires a high voltage, typically hundreds of volts. The lithium niobate transformer (LNT), a piezoelectric voltage transformer, presents a promising solution for miniaturizing high-voltage power supplies due to its compact size, low weight, and high step-up ratio. This study explores the effects of structural parameters and external circuits on the resonant frequency and step-up ratio of the LNT through numerical simulations and experiments. The results indicate the following: (1) the second-order longitudinal vibration frequency of the lithium niobate (LN) plate inversely correlates with its length; (2) the thickness and width of the plate have minimal impact on the frequency; (3) the step-up ratio increases as the plate thickness decreases. The experimental results suggest that LN plates with a thickness of 1 mm are preferable due to the fragility of 0.5 mm plates, especially at the output end. Additionally, optimizing the input circuit enhances voltage amplification, allowing the LNT to generate sufficient output voltage for corona discharge. These findings highlight the potential of LNTs for efficiently and reliably powering small-scale devices.","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944226/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720042","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}

引用次数: 0

Printed Circuit Board Sample Expansion and Automatic Defect Detection Based on Diffusion Models and ConvNeXt.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-26 DOI: 10.3390/mi16030261

Youzhi Xu, Hao Wu, Yulong Liu, Xiaoming Liu

引用次数: 0

Zero-Power, High-Frequency Floating Memristor Emulator Circuit and Its Applications.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-26 DOI: 10.3390/mi16030269

Imen Barraj, Amel Neifar, Hassen Mestiri, Mohamed Masmoudi

引用次数: 0

Transient Gel Diffusiophoresis of a Spherical Colloidal Particle.

IF 3 3区工程技术

Micromachines Pub Date : 2025-02-26 DOI: 10.3390/mi16030266

Hiroyuki Ohshima

{"title":"Transient Gel Diffusiophoresis of a Spherical Colloidal Particle.","authors":"Hiroyuki Ohshima","doi":"10.3390/mi16030266","DOIUrl":"10.3390/mi16030266","url":null,"abstract":"A general theory is presented to analyze the time-dependent, transient diffusiophoresis of a charged spherical colloidal particle in an uncharged gel medium containing a symmetrical electrolyte when an electrolyte concentration gradient is suddenly applied. We derive the inverse Laplace transform of an approximate expression for the relaxation function R(t), which describes the time-course of the ratio of the diffusiophoretic mobility of a weakly charged spherical colloidal particle, possessing a thin electrical double layer, to its steady-state diffusiophoretic mobility. The relaxation function depends on the mass density ratio of the particle to the electrolyte solution, the particle radius, the Brinkman screening length, and the kinematic viscosity. However, it does not depend on the type of electrolyte (e.g., KCl or NaCl), which affects only the steady-state gel diffusiophoretic mobility. It is also found that the expression for the relaxation function in transient gel diffusiophoresis of a weakly charged spherical colloidal particle with a thin electrical double layer takes the same form as that for its transient gel electrophoresis.","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11945194/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720504","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}

引用次数: 0