A Simulation Approach to Study the Effect of SiC Polytypism Factor on Sensitivity of Piezoresistive MEMS Pressure Sensor

Silicon - SiC is a well known wide band gap semiconductor explored for realizing the piezoresistive micro-electro-mechanical systems (MEMS) pressure sensors for harsh environments. In this work a...     

Investigation of MEMS Piezoresistive Pressure Sensor with a Freely Supported Rectangular Silicon Carbide Diaphragm as a Primary Sensing Element for Altitudinal Applications

Silicon - Silicon and Polysilicon are used as piezoresistive materials in MEMS (Micro Electromechanical system) piezoresistive pressure sensors because of its reproducibility and enhanced...     

冲击波压力传感器灵敏度的动态校准

为了定期校准冲击波测试用压力传感器的灵敏度,采用阶跃压力发生器对测量气体介质的传感器灵敏度进行动态校准,产生的阶跃压力信号最高压力为7MPa;采用水动力脉冲发生器对液体介质动态压力传感器的灵敏度进行动态校准,产生的液体脉冲压力信号最高胝力幅值为140MPa,并可由标准比对传感器准确确定幅值。结果表明,两种方法是准确可靠的,与新出厂校准的动态压力测试用传感器的灵敏度进行比较,相对误差不超过0．6％。     

银纳米线电极微结构对柔性压力传感器灵敏度的影响

新型柔性压力传感器具有类似人体皮肤的可拉伸性以及对外力的感知特性,可被用于仿生电子皮肤及各种可穿戴电子设备,近年来引起了学术界和产业界的广泛关注。开发具有优异的传感灵敏度且制作工艺简单、节能、成本低廉的柔性压力传感器具有重要的科学与实际意义。本文以银纳米线(AgNWs)为电极材料,聚二甲基硅氧烷(PDMS)为柔性基底,分别采用PDMS相纸原位固化和抽滤转移固化2种方式制备银纳米线/PDMS复合电极,以聚酰亚胺薄膜(PI)为介电层,将两电极面对面层压封装,得到电容式柔性压力传感器。利用激光共聚焦显微镜和扫描电镜比较了2种制作工艺得到的电极微结构,并研究了上述电极微结构结构对传感器灵敏度的影响。研究结果表明,电极表面银纳米线的蓬松程度及粗糙度能显著影响器件灵敏度。电极表面银纳米线处于较密实状态、粗糙度为0.4μm的传感器灵敏度约为0.43kPa-1;当电极表面银纳米线较为蓬松且粗糙度增大为0.7μm时,传感器灵敏度增大到0.65kPa-1。本文制作的柔性压力传感器具有高灵敏度、低成本的特点,可用于诸如脉搏、心率,发声震动,细微压力变化监控等方面。     

A Flexible and Multipurpose Piezoresistive Strain Sensor Based on Carbonized Phenol Formaldehyde Foam for Human Motion Monitoring

High‐performance flexible strain sensors are extensively studied for various applications including healthcare, robots, and human–computer interaction. In most of the reported research, the fabrication of these sensors involves conductive polymer composites containing expensive metallic or carbon nanomaterials. In this study, commercial phenol formaldehyde foam (PFF) is carbonized by a simple high‐temperature pyrolysis treatment and encapsulated by polydimethylsiloxane (PDMS) to fabricate a flexible and multipurpose piezoresistive strain sensor. The as‐fabricated PDMS‐cPFF strain sensor is capable of detecting various strain modes, including tension, compression, and three‐point bending. Furthermore, the sensor exhibits a high sensitivity with a gauge factor (GF) of ?20.5 under tension and stable signal responses in a frequency range of 0.01–0.5 Hz. The sensor is also capable of accurately monitoring a subtle bending strain of 0.05%. In addition, the sensor shows excellent durability in cyclic loading/unloading tests up to 1000 cycles. The applications of this strain sensor in both large‐ (finger bending and neck movement) and small‐scale human motion monitoring (facial micro‐expression and phonation) are demonstrated, showing its potential for applications in wearable electronics. This work also offers an alternative route to reuse waste thermosetting resins which would otherwise be difficult to recycle.     

Low-Cost,Highly Sensitive,and Flexible Piezoresistive Pressure Sensor Characterized by Low-Temperature Interfacial Polymerization of Polypyrrole on Latex Sponge

Piezoresistive pressure sensors based on sponge are widely concerned because of their wide strain range, convenient signal acquisition, and good compressibility, yet it is still a challenge to acquire sponge-based pressure sensors with low cost and excellent sensing performance. Herein, low-priced FeCl₃^.6H₂O and pyrrole (Py) are dispersed in deionized water to form FeCl₃^.6H₂O/Py solution. Commercial latex sponge is impregnated into this solution to prepare conductive polypyrrole/latex (PPy/latex) sponge through low-temperature interfacial polymerization. The surface of latex sponge is covered by the micro-wrinkled PPy, which endows the PPy/latex sponge with a certain electrical conductivity. The specific porous structure and high elasticity of the latex sponge are the basic conditions for PPy/latex sponge excellent piezoresistive behaviors. PPy/latex sponge based piezoresistive pressure sensor shows high sensitivity (0.084 kPa⁻¹ at below 3.12 kPa), wider sensing range (0–85.0%) and long durability over 3800 s (1800 cycles). At the same time, the ability of the PPy/latex sponge based piezoresistive pressure sensor to monitor human movement has been successfully evaluated in some application scenarios, such as bending fingers, grabbing objects, tiptoe rising, and crouching.     

Low-Cost Biobased Coatings for AM60 Magnesium Alloys for Food Contact and Harsh Environment Applications

Low-cost, environmentally friendly and easily applicable coating for Mg alloys, able to resist in real world conditions, are studied. Coatings already used for other metals (aluminum, steel) and never tested on Mg alloy for its different surface and reactivity were deposited on AM60 magnesium alloys to facilitate their technological applications, also in presence of chemically aggressive conditions. A biobased PA11 powder coating was compared to synthetic silicon-based and polyester coatings, producing lab scale samples, probed by drop deposition tests and dipping in increasingly aggressive, salty, basic and acid solutions, at RT and at higher temperatures. Coatings were analyzed by SEM/EDX to assess their morphology and compositions, by optical and IR-ATR microscopy analyses, before and after the drop tests. Migration analyses from the samples were performed by immersion tests using food simulants followed by ICP-OES analysis of the recovered simulant to explore applications also in the food contact field. A 30 μm thick white lacquer and a 120 μm PA11 coating resulted the best solutions. The thinner siliconic and lacquer coatings, appearing brittle and thin in the SEM analysis, failed some drop and/or dipping test, with damages especially at the edges. The larger thickness is thus the unique solution for edgy or pointy samples. Finally, coffee cups in AM60 alloy were produced, as real word prototypes, with the best performing coatings and tested for both migration by dipping, simulating also real world aging (2 h in acetic acid at 70° and 24 h in hot coffee at 60 °C): PA11 resulted stable in all the tests and no migration of toxic metals was observed, resulting a promising candidate for many real world application in chemically aggressive environments and also food and beverage related applications.     

Design of Dual-Gate P-type IMOS Based Industrial Purpose Pressure Sensor

Silicon - In this treatise, we have proposed a Single Material Gate–Dual Gate Impact Ionization Metal Oxide Semiconductor (SMG DG-IMOS) based Pressure Sensor. The pressure sensor has the most...     

基于压力传感器的水刀切割优化控制系统

水刀切割工件质量与水刀的速度、喷流压力、砂粒直径、流量摩擦流速及喷嘴的几何参数等有关,但是只有速度可以随意控制,笔者设计一种基于压力传感器的水刀切割优化系统,解决了水射流技术存在的缺点。     

Sensitivity and Optimization of Peel Strength Based on Composition of Adhesives for Footwear Industry

In order to contribute to the research and development of adhesives for the footwear industry, this paper aims to develop a model capable to predict and optimize the peel strength from the composition of adhesives. The proposed approach is based on three stages: experimental planning of measurements, global sensitivity analysis for uncertainty propagation, and optimization procedure. The design variables are the weight percentages of the solid raw material constituents such as polyurethane, resins, and additives of the adhesive joint. Considering the experimental results obtained for Taguchi design points as input/output patterns, an artificial neural network (ANN) is developed based on supervised evolutionary learning. Using the developed ANN a global sensitivity analysis procedure is implemented and the variability of the structural response of adhesive joint is studied. The optimal solution for adhesives composition for maximum peel strength is investigated based on ANN model and using a genetic algorithm. The proposed approach is able to predict the optimal peel strength including its sensitivity to uncertainties. The results show that the sensitivities of design variables belonging to polyurethane and additive groups are important for optimal adhesive joint. The optimal peel strength based on proposed approach is consistent with the experimental testing data.     

消除材料敏感性的电涡流传感器测量电路

被测材料的电磁特性会影响传感器的输出性能,限制其使用范围。为此,在分析阻抗投影变换原理的基础上,设计了一种能实现该原理的测量电路,用以消除传感器对被测材料的敏感性。11mm传感器输出测试实验的结果表明:所用7种被测材料经线性补偿后的输出特性曲线近似重合,可用一条直线替代,实现了消除材料敏感性的功能;计算出的传感器材料敏感性误差为±1.8%。     

基于模糊优化压力容器的设计

在压力容器常规设计方法单纯根据强度理论进行设计的基础上,提出综合考虑压力容器设计、制造、检验、试运行和工作环境等因素对设计计算的影响。根据模糊数学理论,应用模糊数学优化的方法,把影响压力容器的各因素和等级进行模糊综合评判,得到目标函数约束条件的最优水平截集,从而建立压力容器模糊优化设计的数学模型,寻求最适宜的压力容器设计方案。     

Graphene and MXene-based Sponge Pressure Sensor Array for Rectal Model Pressure Detection

Flexible sensor is one of the prevalent directions in the sensor field, and the sensing material and structure are the main aspects that affect the performance of the sensor. This paper studies a flexible pressure sensor based on Graphene/MXene-PDMS @ sponge. Using the porous skeleton structure of sponge and the high conductivity and synergy of Graphene and MXene to prepare a set of high sensitivity (0.053kPa⁻¹), high stability (2000 cycles loading), and variability (0–35 kPa detection limit), all-in-one sensor. In the rectal model pressure detection experiment, the sensor array can effectively detect static pressure, systolic pressure, and corresponding abnormal pressure detection. Experimental results show that the sensor has a good prospect in detecting rectal pressure.     

压力容器分析设计的结构优化方法

压力容器应力分析设计法正在我国石油化工等行业得到迅速地普及应用。应用ANSYS软件提供的参数化设计语言和优化设计等高级分析技术，可以采用一种新的“结构优化法”进行压力容器的应力分析设计。该方法具有设计计算周期短、工作量小等优点，具有应用推广价值。     

基于优化灰色神经网络法的压力容器裂纹扩展预测

根据灰色预测和神经网络理论建立了裂纹扩展预测的有效模型,并对其进行了优化和改进,通过实例计算表明,改进后的灰色神经网络法的预测精度更高,为裂纹扩展和寿命预测提供了一种参考方法。     

Improvement in Sensing Characteristics of Silicon Microstructure based MEMS Capacitive Sensor for Automotive Applications

Silicon - Capacitive pressure sensors have become a reasonable choice due to their low power consumption, energy efficiency, and robustness. In this paper, a thorough investigation of MEMS based...     

悬臂梁结构光纤光栅电流传感器的优化

针对电力系统对电流测量高精度的要求,设计了一种基于等强度悬臂梁结构的光纤光栅电流传感器。将两根光栅分别粘贴于等腰三角形结构的悬臂梁上下表面,末端永磁体材料振子置于两螺线圈中间。当螺线圈接通电流时,形成的磁场将会引起永磁体振子偏移,进而引起光栅中心波长的变化。采用差分方式建立电流大小与光栅波长变化之间的关系,在提高测量灵敏度的同时消除了温度对测量结果的影响。实验结果表明:在0~5A的范围内,利用光纤光栅波长变化可准确反演待测电流值,与理论计算值相比,误差小于1.2%。     

基于ANSYS的压力容器壁厚优化设计

利用大型有限元分析软件ANSY对压力容器进行壁厚分析设计,优化容器壁厚合理控制材料的使用成本,提高压力容器整体结构的载荷能力,可以实现最佳的优化设计目的,将从ANSYS这种有限元分析的软件入手,对于压力容器的壁厚的优化方案进行一定的探讨,以供广大同僚参考交流使用。     

基于压力梯度的注塑模浇口位置优化算法

给出了判断熔体充模流动是否平衡的判据,并根据熔体充模流动的物理本质,构造了基于压力梯度的搜索方法来优化浇口位置,以实现熔体平衡充填模具型腔的目的。算例表明基于压力梯度的搜索方案简单有效。     

海上油田用压力测量仪表的优化

由于海上油田的特点,为了达到压力测量的效果,优选压力测量仪表,合理控制生产过程的压力,保证海上生产平台的安全。压力测量仪表的种类繁多,依据海上油田的特点,优选抗腐蚀特性强的压力测量仪表,满足海上油田生产的需要,不断提高海上油田的生产效率。