Design, fabrication and experiment of a MEMS piezoresistive high-g accelerometer

Yulong Zhao,Xiaobo Li,Jing Liang,Zhuangde Jiang 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.3

High-g accelerometers are widely used in explosion and shock measurement. This paper describes a MEMS piezoresistive high-g accelerometer whose range is more than 50000g. It is designed on the basis of silicon on insulator (SOI) solid piezoresistive chip. The chip has a structure where both ends of the beam are fixed. Through the stress analysis and mode analysis of the accelerometer, the detailed parameters of the structure are established. The experimental results obtained from the drop hammer shock machine test and live-fire test show good properties of the accelerometer such as good output characteristic, repeatability and fast response speed. Therefore, the accelerometer in this paper meets the requirement of explosion and shock measurement basically.

An ultra-high pressure sensor based on SOI piezoresistive material

Yulong Zhao,Xudong Fang,Zhuangde Jiang,Libo Zhao 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.8

This paper describes an ultra-high pressure sensor which is in urgent need and widely used in defense industry and petroleum industry. It is designed on the combination of micro Silicon on Insulator (SOI) solid piezoresistive chip based on Micro Electro Mechanical Systems (MEMS) technique and cylindrical elastic body that could successfully convert dynamic ultra-high pressure measurement in explosion to strain measurement. Performances of the sensor including size, sensitivity, and linearity are investigated with experiment data. It’s proved that the dynamic ultra-high sensor in the range of 2GPa in this paper is successful in pressure measurement in explosion. The research of ultra-high pressure sensor in this paper could not only provide a reference for the improvement of explosive property, but also lay a foundation for research of pressure sensor in the range of 10GPa of the next step.

An ultra-high pressure sensor with cylinder structure

Libo Zhao,Xin Guo,Xiawei Meng,Rahman Hebibul,Yulong Zhao,Jianzhu Wang,Zhuangde Jiang 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.8

Based on strain-resistance effect, an ultra-high pressure sensor has been developed with the range of 0-500 MPa. It is mainly composed of the elastic element and sensitive element. This sensor’s range is determined by the elastic element’s structure and material. In order to endure the ultra-high pressure, the elastic element’s material is selected as spring steel, and its structures are analyzed and simulated. After that, the metal strain gauge as the sensitive element is packaged on the elastic element. Then the sensor is developed after some compensation processes are carried out. In the end, the sensor is calibrated. The results show that the sensor has good performance,such as the accuracy of 0.35%FS, which meets the requirements of aerospace, weapons and other fields.

Thioredoxin A of Streptococcus suis Serotype 2 Contributes to Virulence by Inhibiting the Expression of Pentraxin 3 to Promote Survival Within Macrophages

Zhao Chijun,Jia Xinglin,Pan Yanying,Liao Simeng,Zhang Shuo,Ji Chunxiao,Kuang Guangwei,Wu Xin,Liu Quan,Tang Yulong,Fang Lihua 한국미생물학회 2023 The journal of microbiology Vol.61 No.4

Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen that can infect humans in contact with infected pigs or their byproducts. It can employ different types of genes to defend against oxidative stress and ensure its survival. The thioredoxin (Trx) system is a key antioxidant system that contributes adversity adaptation and pathogenicity. SS2 has been shown to encode putative thioredoxin genes, but the biological roles, coding sequence, and underlying mechanisms remains uncharacterized. Here, we demonstrated that SSU05_0237-ORF, from a clinical SS2 strain, ZJ081101, encodes a protein of 104 amino acids with a canonical CGPC active motif and an identity 70–85% similar to the thioredoxin A (TrxA) in other microorganisms. Recombinant TrxA efficiently catalyzed the thiol-disulfide oxidoreduction of insulin. The deletion of TrxA led to a significantly slow growth and markedly compromised tolerance of the pathogen to temperature stress, as well as impaired adhesion ability to pig intestinal epithelial cells (IPEC-J2). However, it was not involved in H2O2 and paraquat-induced oxidative stress. Compared with the wild-type strain, the ΔTrxA strain was more susceptible to killing by macrophages through increasing NO production. Treatment with TrxA mutant strain also significantly attenuated cytotoxic effects on RAW 264.7 cells by inhibiting inflammatory response and apoptosis. Knockdown of pentraxin 3 in RAW 264.7 cells was more vulnerable to phagocytic activity, and TrxA promoted SS2 survival in phagocytic cells depending on pentraxin 3 activity compared with the wild-type strain. Moreover, a co-inoculation experiment in mice revealed that TrxA mutant strain is far more easily cleared from the body than the wild type strain in the period from 8–24 h, and exhibits significantly attenuated oxidative stress and liver injury. In summary, we reveal the important role of TrxA in the pathogenesis of SS2.

Braking Torque Analysis and Control Method of a New Motor with Eddy-Current Braking and Heating System for Electric Vehicle

Zhao Xiaojuan,Zhang Yulong,Ye Lezhi 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.5

To solve the problem of the serious mileage reduction of electric vehicles in winter, this paper introduces a new type of motor with eddy current braking and heating system (EBHS). EBHS can convert the vehicle’s kinetic energy into the thermal energy which can be used for heating the cabin and the battery at the right temperature. This paper proposes the structural layout and operating modes with the novel motor. The air gap magnetic density of the ECR is calculated by the magnetic circuit method. The braking torque is solved by the transient electromagnetic finite element method. The eddy current loss power at different speeds is used for analyzing heat performance. Based on MATLAB / Simulink environment, the fuzzy control method is used to simulate the EBHS’s braking energy efficiency. Compared with PTC heating, the power consumption of the new motor is reduced by 25 % and the cabin can reach 20 °C in 160 seconds. Finally, it is verified by bench test that the retarder stator stayed within 110 °C when it is continuously operated for 12 minutes. The braking torque of the finite element analysis result meet the test value, and the error rate is not higher than 11.7 %.

Investigation on Texture Evolution Mechanism of NiTiFe Shape Memory Alloy Under Plane Strain Compression

Yulong Liang,Qiang He,Shuyong Jiang,Chengzhi Zhao 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

Texture evolution of NiTiFe shape memory alloy (SMA) is investigated during plane strain compression based on crystalplasticity finite element method (CPFEM) and electron back-scatter diffraction (EBSD) experiment. The deformation texturesof NiTiFe SMA are not influenced very considerably after experiencing recrystalline annealing at 600 °C for 1 h. Based onthe results of CPFEM, the main activated slip systems of NiTiFe SMA are ⟨100⟩/{110} and ⟨111⟩/{110} ones during planestrain compression. According to the relationship between texture components and activated slip systems put forward in thisstudy, ⟨110⟩ direction would rotate to rolling direction, whereas ⟨100⟩ and ⟨111⟩ directions would rotate to normal direction. These rotations contribute to the formation of γ-fibre texture and α-fibre texture in NiTiFe SMA. The deformation texturecomponents predicted by CPFEM and determined by EBSD were compared with each other in detail. Due to the startupof the pencil glide and multiple slip in the refined microstructure, there are some differences between texture componentspredicted by CPFEM and texture components determined by EBSD. The deformation heterogeneity is discussed in termsof rotation angle at each integration point in the study.

Topology Optimization and Design Realization of Magnetically-Coupled Resonant Wireless Power Transfer System with LCL-S Structure

Jingying Zhao,Xuefeng Wang,Yulong Cui,Sinuo Zhou 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.4

Magnetically-coupled resonant wireless power transfer (MCR-WPT) system with LCL-S structure is developing for higher transmission characteristics. This paper improves the resonance topology structure by adding a compensation capacitor in the transmitting side and proposes a parameter confi guration method with equivalent impedance. The transmission characteristics are analyzed fi rst based on simulation method to determine the parameters for the system requirements of 3 kW output power at working frequency of 85 kHz. Then the improved MCR-WPT system is developed. The realization methods of key modules such as electromagnetic coupling mechanism and drive circuit are given. The experiments are designed and are used to analyze the eff ect of diff erent frequency and diff erent distance on transmission characteristics. Output power and transmission effi ciency of the designed system can be 3141 W and 91% respectively. In addition, the inverter’s performance and the system electromagnetic radiation state are evaluated. The results show that the designed system can provide an eff ective means for 3 kW WPT application at 85 kHz.

Optical and Magnetic Properties of Copper Doped Zinc Oxide Nanofilms

Shifeng Zhao,Yulong Bai,Jieyu Chen,Alima Bai,Wei Gao 한국자기학회 2014 Journal of Magnetics Vol.19 No.1

Copper doped Zinc Oxide nanofilms were prepared using a simple and low cost wet chemical method. The microstructures, phase structure, Raman shift and optical absorption spectrum as well as magnetization were investigated for the nanofilms. Room temperature ferromagnetism has been observed for the nanofilms. Structural analyses indicated that the films possess wurtzite structure and there are no segregated clusters of impurity phase appreciating. The results show that the ferromagnetism in Copper doped Zinc Oxide nanofilms is driven either by a carrier or defect-mediated mechanism. The present work provides an evidence for the origin of ferromagnetism on Copper doped Zinc Oxide nanofilms.

A monolithic silicon multi-sensor for measuring three-axis acceleration, pressure and temperature

Xu Jingbo,Zhao Yulong,Jiang Zhuangde,Sun Jian 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.4

A monolithic multi-sensor for small unmanned aerial vehicles is presented in the paper; it consists of a three-axis piezoresistive accelerometer, a piezoresistive absolute pressure sensor and a silicon thermistor temperature sensor. The accelerometer is designed with four silicon beams supporting the seismic mass and appropriate piezoresistors arrangement to detect three-axis acceleration and greatly reduce cross-axis sensitivities. For minimizing the effect of stress on the temperature sensor, the thermistor is designed along [100] and [010] crystal orientation. The multi-sensor is fabricated on SOI wafers by using MEMS bulk-micromachining technology. Some effective micromachining steps are applied in the fabrication. The two-step wet anisotropic etching process on the backside of the wafers can form the whole backside shape of the multi-sensor. The metal electrode sputtered on the Pyrex glass can avoid sticking between the Pyrex glass and the seismic mass in the process of anodic bonding. The die size of the multi-sensor is 4×6×0.9mm3. The measured results show that the multi-sensor is appropriate for its application field.

INFLUENCE OF BILLET SIZE ON THE DEFORMATION INHOMOGENEITY OF MATERIAL PROCESSED BY EQUAL CHANNEL ANGULAR PRESSING

TAO SUO,YULONG LI,FENG ZHAO 한국소성가공학회 2008 한국소성가공학회 컨퍼런스 Vol.2008 No.10