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Highly-sensitive wafer-scale transfer-free graphene MEMS condenser microphones

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Microsystems & Nanoengineering 2024年第1期10卷 267-275页

作者： Roberto Pezone Sebastian Anzinger Gabriele Baglioni Hutomo Suryo Wasisto Pasqualina M.Sarro Peter G.Steeneken Sten Vollebregt Laboratory of Electronic Components Technology and Materials(ECTM)Department of MicroelectronicsDelft University of TechnologyDelftThe Netherlands Infineon Technologies AG Am Campeon 1-15Neubiberg 85579Germany Kavli Institue of Nanoscience Department of Quantum NanoscienceDelft University of TechnologyDelftthe Netherlands department of precision and Microsystems Engineering(PME) Delft University of TechnologyDelftThe Netherlands

Since the performance of micro-electro-mechanical system(MEMS)-based microphones is approaching fundamental physical,design,and material limits,it has become challenging to improve *** works have demonstrated graphene’s suitability as a microphone *** potential for achieving smaller,more sensitive,and scalable onchip MEMS microphones is yet to be *** address large graphene sizes,graphene-polymer heterostructures have been proposed,but they compromise performance due to added polymer mass and *** work demonstrates the first wafer-scale integrated MEMS condenser microphones with diameters of 2R=220-320μm,thickness of 7 nm multi-layer graphene,that is suspended over a back-plate with a residual gap of 5μ*** microphones are manufactured with MEMS compatible wafer-scale technologies without any transfer steps or polymer layers that are more prone to contaminate and wrinkle the *** designs,all electrically integrated are fabricated and characterized allowing us to study the effects of the introduction of a back-plate for capacitive *** devices show high mechanical compliances C_(m)=0.081-1.07μmPa^(−1)(10-100×higher than the silicon reported in the state-of-the-art diaphragms)and pull-in voltages in the range of 2-9.5 *** addition,to validate the proof of concept,we have electrically characterized the graphene microphone when subjected to sound *** estimated sensitivity of S_(1kHz)=24.3-321 mV Pa^(−1)for a V_(bias)=1.5 V was determined,which is 1.9-25.5×higher than of state-of-the-art microphone devices while having a~9×smaller area.

关键词： transfer plate approaching

Laser-assisted direct roller imprinting of large-area microstructured optical surfaces

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Microsystems & Nanoengineering 2024年第1期10卷 257-266页

作者： Keisuke Nagato Ken Takahashi Yuki Yajima Masayuki Nakao department of mechanical Engineering Graduate School of EngineeringThe University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-8656Japan

In this study,a high-throughput fabrication method called laser-assisted direct roller imprinting(LADRI)was developed to lower the cost of nanoimprinting large-area polymer films and to address problems associated with nanoimprinting,namely,microstructural damage and precision in flatness of entire *** LADRI,the laser directly heats the microstructured surface of the roller mold,which heats and melts the surface of a polymethyl methacrylate(PMMA)film to replicate the microstructures on the mold *** this study,the effects of laser power density,scanning speed,size of the microstructures,and contact pressure on the replication speed were investigated *** replication speed increased as the power and scanning speed ***,because the film required heating until it filled the entire depth of the microstructure,an appropriate replication speed was *** result was supported by simulation of the temperature distribution inside the mold and the PMMA using transient heat conduction *** demonstrate the applications of LADRI,two different optical surfaces were replicated:an antireflection(AR)structure with conical structures sized several hundred nanometers and a lightextraction structure with a microlens array(MLA)comprising 10μm lenses,for display and illumination,*** replication degree of the MLA was governed by the contact *** flow simulation indicated that the heat conduction and flow speeds of the melted PMMA surface were comparable within several tens of *** addition,the reflectivity of the AR structure decreased from 4 to 0.5%,and the light intensity of the light-extraction structure increased by a factor of 1.47.

关键词： microstructure roller conduction

Cyclic-acyclic monomers metathesis polymerization to access photodegradable polydicyclopentadiene and polyethylene-like materials

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Science China Chemistry 2024年第4期67卷 1311-1315页

作者： Wu Li Daohong Liao Yougui Li Guifu Si Changle Chen School of Chemistry and Chemical Engineering Hefei University of TechnologyHefei 230009China Key Laboratory of precision and Intelligent Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

The development of degradable and recyclable polymers is an attractive strategy to tackle the post-consumption pollution issue of commercial ***-acyclic monomers metathesis polymerization(CAMMP)has been recently reported to produce degradable thermoset,thermoplastic and elastomeric polymers,and their degradability is enabled with addition of various *** this contribution,we demonstrate that the utilization of diene comonomers containing photodegradable moiety can give access to thermoset and thermoplastic materials bearing photo-degradation *** copolymerization of a series easily accessible diene comonomers bearing photodegradable ortho-nitrobenzyl moieties with dicyclopentadiene(DCPD)or cyclooctene(COE)leads to the formation of photodegradable p DCPD thermosets and p COE thermoplastic polymers with mechanical properties comparable to their non-degradable *** importantly,their photo-degradation properties can be efficiently tuned with the addition of ultraviolet absorber during in-situ polymerization.

关键词： metathesis polymerization photodegradable polydicyclopentadiene polyethylene-like materials

Synthesis of Ultra-High-Molecular-Weight Polyethylene by Transition-Metal-Catalyzed Precipitation Polymerization

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precision Chemistry 2024年第2期2卷 63-69页

作者： Wenbing Wang Quan Wang Chen Zou Changle Chen Key Laboratory of precision and Intelligent Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

Ultra-high-molecular-weight polyethylene(UHMWPE)plays an important role in many important fields as engineering *** this contribution,a precipitation polymerization strategy is developed by combination of highly active phosphino-phenolate nickel catalysts with polymer-insoluble solvent(heptane)to access UHMWPE(Mn up to 8.3×10^(6)g mol^(-1))with good product morphology,free-flowing characteristics,and great mechanical *** with the academically commonly used aromatic solvent(toluene),the utilization of heptane offers simultaneous enhancement in important parameters including activity,polymer molecular weight,and catalyst thermal *** system can also generate polar functionalized UHMWPE with molecular weight of up to 1.6×10^(6)g mol^(-1)in the copolymerization of ethylene with polar *** importantly,this precipitation polymerization strategy is generally applicable to several representative transition metal catalyst systems,leading to UHMWPE synthesis with good product morphology control.

关键词： transition metal catalysts polyolefin UHMWPE precipitation polymerization polar monomer

Intelligent solubility estimation of gaseous hydrocarbons in ionic liquids

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Petroleum 2024年第1期10卷 109-123页

作者： Behnaz Basirat Fariborz Shaahmadi Seyed Sorosh Mirfasihi Abolfazl Jomekian Bahamin Bazooyar Ahvaz Faculty of Petroleum Engineering Petroleum University of Technology (PUT) School of Engineering & Physical Sciences Heriot Watt University department of Fluids & Environment The University of Manchester department of Engineering Chemical Engineering Group Esfarayen University of Technology mechanical and Aerospace Engineering Brunel University London

The research focuses on evaluating how well new solvents attract light hydrocarbons, such as propane,methane, and ethane, in natural gas sweetening units. It is important to accurately determine the solubility of hydrocarbons in these solvents to effectively manage the sweetening process. To address this challenge, the study proposes using advanced empirical models based on artificial intelligence techniques like Multi-Layer Artificial Neural Network(ML-ANN), Support Vector Machines(SVM), and Least Square Support Vector Machine(LSSVM). The parameters for the SVM and LSSVM models are estimated using optimization methods like Genetic Algorithm(GA), Particle Swarm Optimization(PSO), and Shuffled Complex Evolution(SCE). Data on the solubility of propane, methane, and ethane in various ionic liquids are collected from reliable literature sources to create a comprehensive database. The proposed artificial intelligence models show great accuracy in predicting hydrocarbon solubility in ionic liquids. Among these, the hybrid SVM models perform exceptionally well, with the PSO-SVM hybrid model being particularly efficient computationally. To ensure a comprehensive analysis, different examples of hydrocarbons and their order are included. Additionally, a comparative analysis is conducted to compare the AI models with the thermodynamic COSMO-RS model for solubility analysis. The results demonstrate the superiority of the AI models, as they outperform traditional thermodynamic models across a wide range of data. In conclusion, this study introduces advanced artificial intelligence algorithms such as ML-ANN, SVM, and LSSVM in accurately estimating the solubility of hydrocarbons in ionic liquids. The incorporation of optimization techniques and variations in hydrocarbon examples improves the accuracy, precision, and reliability of these intelligent models. These findings highlight the significant potential of AI-based approaches in solubility analysis and emphasize their superiori

关键词： Solubility Gaseous hydrocarbon Intelligent models Ionic liquids

A Study on Enhancing Chip Detection Efficiency Using the Lightweight Van-YOLOv8 Network

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Computers, Materials & Continua 2024年第4期79卷 531-547页

作者： Meng Huang Honglei Wei Xianyi Zhai School of mechanical Engineering and Automation Dalian Polytechnic UniversityDalian116034China

In pursuit of cost-effective manufacturing,enterprises are increasingly adopting the practice of utilizing recycled semiconductor *** ensure consistent chip orientation during packaging,a circular marker on the front side is employed for pin alignment following successful functional ***,recycled chips often exhibit substantial surface wear,and the identification of the relatively small marker proves ***,the complexity of generic target detection algorithms hampers seamless *** these issues,this paper introduces a lightweight YOLOv8s-based network tailored for detecting markings on recycled chips,termed ***,to alleviate the influence of diminutive,low-resolution markings on the precision of deep learning models,we utilize an upscaling approach for enhanced *** technique relies on the Super-Resolution Generative Adversarial Network with Extended Training(SRGANext)network,facilitating the reconstruction of high-fidelity images that align with input ***,we replace the original YOLOv8smodel’s backbone feature extraction network with the lightweight VanillaNetwork(VanillaNet),simplifying the branch structure to reduce network ***,a Hybrid Attention Mechanism(HAM)is implemented to capture essential details from input images,improving feature representation while concurrently expediting model inference *** results demonstrate that the Van-YOLOv8 network outperforms the original YOLOv8s on a recycled chip dataset in various ***,it demonstrates superiority in parameter count,computational intricacy,precision in identifying targets,and speed when compared to certain prevalent algorithms in the current *** proposed approach proves promising for real-time detection of recycled chips in practical factory settings.

关键词： Lightweight neural networks attention mechanisms image super-resolution enhancement feature extraction small object detection

Optimal Shape Factor and Fictitious Radius in the MQ-RBF:Solving Ill-Posed Laplacian Problems

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3189-3208页

作者： Chein-Shan Liu Chung-Lun Kuo Chih-Wen Chang Center of Excellence for Ocean Engineering Taiwan Ocean UniversityKeelung202301TaiwanChina department of mechanical Engineering National United UniversityMiaoli36063TaiwanChina

To solve the Laplacian problems,we adopt a meshless method with the multiquadric radial basis function(MQRBF)as a basis whose center is distributed inside a circle with a fictitious radius.A maximal projection technique is developed to identify the optimal shape factor and fictitious radius by minimizing a merit function.A sample function is interpolated by theMQ-RBF to provide a trial coefficient vector to compute the merit *** can quickly determine the optimal values of the parameters within a preferred rage using the golden section search *** novel method provides the optimal values of parameters and,hence,an optimal MQ-RBF;the performance of the method is validated in numerical ***,nonharmonic problems are transformed to the Poisson equation endowed with a homogeneous boundary condition;this can overcome the problem of these problems being *** optimal MQ-RBF is extremely *** further propose a novel optimal polynomial method to solve the nonharmonic problems,which achieves high precision up to an order of 10^(−11).

关键词： Laplace equation nonharmonic boundary value problem Ill-posed problem maximal projection optimal shape factor and fictitious radius optimal MQ-RBF optimal polynomial method

An Automatic Implementation of Oropharyngeal Swab Sampling for Diagnosing Respiratory Infectious Diseases via Soft Robotic End-Effectors

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Chinese Journal of mechanical Engineering 2024年第2期37卷 55-67页

作者： Yafeng Cui Wenjie Yu Jingjing Li Qi Shao Ding Weng Guoping Yin Xiaohao Zhang Xinjun Liu Jingying Ye Jiadao Wang Huichan Zhao department of mechanical Engineering Tsinghua UniversityBeijing 100084China Beijing Huakang Tongbang Technology Company Beijing 102609China department of Otorhinolaryngology Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China Tianjin Research Institute for Advanced Equipment Tsinghua UniversityTianjin 300300China

The most widely adopted method for diagnosing respiratory infectious diseases is to conduct polymerase chain reaction(PCR)assays on patients’respiratory specimens,which are collected through either nasal or oropharyngeal *** manual swab sampling process poses a high risk to the examiner and may cause false-negative results owing to improper *** this paper,we propose a pneumatically actuated soft end-effector specifically designed to achieve all of the tasks involved in swab *** soft end-effector utilizes circumferential instability to ensure grasping stability,and exhibits several key properties,including high load-to-weight ratio,error tolerance,and variable swab-tip stiffness,leading to successful automatic robotic oropharyngeal swab sampling,from loosening and tightening the transport medium tube cap,holding the swab,and conducting sampling,to snapping off the swab tail and sterilizing *** an industrial collaborative robotic arm,we integrated the soft end-effector,force sensor,camera,lights,and remote-control stick,and developed a robotic oropharyngeal swab sampling *** this swab sampling system,we conducted oropharyngeal swab-sampling tests on 20 *** Digital PCR assay results(RNase P RNA gene absolute copy numbers for the samples)revealed that our system successfully collected sufficient numbers of cells from the pharyngeal wall for respiratory disease *** summary,we have developed a pharyngeal swab-sampling system based on an“enveloping”soft actuator,studied the sampling process,and imple-mented whole-process robotic oropharyngeal swab-sampling.

关键词： Diagnosis Medical robot Soft end-effector Swab-sampling Digital PCR

YOLO-O2E:A Variant YOLO Model for Anomalous Rail Fastening Detection

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Computers, Materials & Continua 2024年第7期80卷 1143-1161页

作者： Zhuhong Chu Jianxun Zhang Chengdong Wang Changhui Yang department of Computer Science and Engineering Chongqing University of TechnologyChongqing400054China Institute of Flexible Electronics(Future Technologies) Xiamen UniversityXiamen361000China College of mechanical Engineering Chongqing University of TechnologyChongqing400054China

Rail fasteners are a crucial component of the railway transportation safety *** fasteners,distinguished by their high length-to-width ratio,frequently encounter elevated failure rates,necessitating manual inspection and *** inspection not only consumes time but also poses the risk of potential *** the advancement of deep learning technology in rail fasteners,challenges such as the complex background of rail fasteners and the similarity in their states are *** have proposed an efficient and high-precision rail fastener detection algorithm,named YOLO-O2E(you only look once-O2E).Firstly,we propose the EFOV(Enhanced Field of View)structure,aiming to adjust the effective receptive field size of convolutional kernels to enhance insensitivity to small spatial ***,The OD_MP(ODConv and MP_2)and EMA(EfficientMulti-Scale Attention)modules mentioned in the algorithm can acquire a wider spectrum of contextual information,enhancing the model’s ability to recognize and locate ***,we collected and prepared the GKA dataset,sourced from real train *** testing on the GKA dataset and the publicly available NUE-DET dataset,our method outperforms general-purpose object detection *** the GKA dataset,our model achieved a mAP 0.5 value of 97.6%and a mAP 0.5:0.95 value of 83.9%,demonstrating excellent inference ***-O2E is an algorithm for detecting anomalies in railway fasteners that is applicable in practical industrial settings,addressing the industry gap in rail fastener detection.

关键词： Rail fastening detection deep learning anomalous rail fastening variant YOLO feature reinforcement