bluuebunny/crossref_metadata_2025 huggingface dataset:
Micromachined W-Band Waveguide Duplexer Design Based on MEMS Technology
Authors: Liu Hui Liang , Zhao Chen Xu , Li Ling , Liu Ze Wen
Published: July 2013

This paper presents a novel high performance W-band MEMS duplexer for digital signal transceiver applications. The design of duplexer filters follows the insertion loss method with a Chebyshev polynomial to meet the desired spectral responses. The insertion loss and return loss of the optimized duplexer are -0.3dB and -18dB respectively, while the isolation between two pass bands is -55dB. A micro-fabrication process is designed based on MEMS technology. The deep reactive ion etching (DRIE) is used for high-aspect-ratio filter cavity mold structure. Micro-electroforming, plastic embossing, and electroplating techniques are used for low-cost and high-precision mass production program for the duplexer. Fabrication error tolerance is analyzed and it is reasonable to control the shift of frequency and return loss in the range of 0.05GHz and 2dB respectively with the designed fabrication process based on MEMS technology. It proves that the proposed micromachining fabrication technique is suitable for high performance W-band waveguide filter and duplexer design in terms of stability of RF performance.
High Impact Dynamic Simulation of Planar S-Form Micro-Spring
Authors: Wang Ying , Lou Wen Zhong , Fu Yue
Published: July 2013

This paper describes the research status of MEMS spring used in fuze. For the Nickel planar S-form micro-spring, according to its application environment and design requirements, the length of the straight beam was taken as the only variable to study the variation of the micro-spring dynamic stiffness under high impact load. These researches can provide some reference views to design applications and reliability analysis of micro-spring used in the munitions, and also can lay the foundation for the response characteristics of the micro-scale elastic components under impact load.
Design and Simulation Analysis of a New Type of Micro Metal-Plastic Heat Radiator
Authors: Zhao Zhong Li , Zhou Bao Jun , Zhuang Jian , Wu Da Ming , Zhang Ya Jun , Zheng Xiu Ting , Dang Kai Fang
Published: July 2013

With the development of micro-nanomachining technology (MNMT), micro heat radiator is getting attention. In this paper, the heat dissipation mechanism of light emitting diode (LED) ball lamp is introduced. And the LED heat radiator is simplified. On the basis of that, a new type of micro metal-plastic heat radiator of LED is put forward. And the LED heat radiator is simplified. A series of numerical simulations are carried out to compare the heat dissipation performance of micro heat radiator respectively made by metal, plastic, metal-plastic composite by the FloEFD software. Micro metal-plastic heat radiator structures, including fin spacing, fin thickness, fin height and substrate thickness, are carry out to be simulated.
Design and Simulation of Switched Capacitor Filter for Speed Change Parameter Converter
Authors: Liu Xiao Wei , Yang Jian , Chen Song , Liu Liang , Zhang Rui , Chen Wei Ping
Published: July 2013

In this paper, we design a high-order switched capacitor filter for rapid change parameter converter. This design uses a structure which consists of three biquads filter sub-units. The design is a 6th-order SC elliptic low-pass filter, and the sample frequency is 250 kHz. By the MATLAB Simulink simulation, the system can meet the design requirements in the time domain. In this paper, the 6th-order switched capacitor elliptic low-pass filter was implemented under 0.5 um CMOS process and simulated in Cadence. The final simulation results show that the pass-band cutoff frequency is 10 kHz, and the maximum pass-band ripple is about 0.106 dB. The stop-band cutoff frequency is 20 kHz, and the minimum stop-band attenuation is 74.78 dB.
Preparation of Polyaniline @ Polypyrrole Conductive Composite via In Situ Polymerization
Authors: Feng Hui Xia , Wang Bing , Tan Lin , Chen Na Li
Published: July 2013

We prepared the polyaniline@polypyrrole (PAn@PPy) conductive composite by a novel method. The struction like Pre-prepared PAn as the core and PPy as the shell for the composite has been prepared by in-situ polymerization. The PAn@PPy conductive composite presents an electrical conductivity of 12.5 S/cm, which is much higher than pure PAn. The synthesized polymer composites are characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Thermogravimetric analysis (TG). The results indicated that PPy successfully grafted on PAn and the heat resistance of nanocomposite is remarkably increased.
Electrohydrodynamic Printing via Spinneret with Conductive Probe
Authors: Lin Yi Hong , He Guang Qi , Liu Hai Yan , Wei Jin , Zheng Jian Yi , Zheng Gao Feng , Sun Dao Heng
Published: July 2013

Stability jet ejection and precision deposition are the two keys for industrial application of electrohydrodynamic printing. In this paper, inserted conductive probe is utilized to gain stability jet, which would increase the electrical field strength, reduce the back flow, onset and sustaining voltage. Lower applied voltage would enhance the stability of electrospun jet, in which fine jet can be used to direct-write orderly Micro/Nano-structure. With the guidance and constrain of inserted probe, the oscillating angle range of electrohydrodynamic jet is decreased to 3°from 15°, and the width of printed structures is 21μm in average that is much narrower than that printed from spinneret without probe (74μm in average). Spinneret with tip provides a good way to improve the control level of electrohydrodynamic printing, which would accelerate the industrial application of electrohydrodynamic printed Micro/Nano structure.
Modeling of Particle Migration inside Vibration Bubbles in Bubble-Stretching Dispersion Method
Authors: Wang Fei , Zhang Yan Ling , Zhao Liang , Wang Xiao Ming
Published: July 2013

Bubble-stretching based dispersion method can be used to prevent the agglomeration of nanoparticles during the process of preparing nanocomposites, whereas its effectiveness is restricted by the practically low migration ratio of particles onto the bubble wall. Theoretical models for bubble vibration and particle migration have been presented, followed by numerically study on effects of different parameters on migration ratio of particles on to the bubble wall. The numerical results have shown that bubble initial radius, bubble initial pressure and particle diameters impact the particle migration ratio obviously and it is found that the particle migration ratio can be improved effectively through the optimal control of the vibration parameters of the bubble happed in the dispersion process. Therefore, this article provides a theoretical basis for the efforts on increasing the particles migration ratio and thus the dispersion effectiveness of nanoparticles in polymer melt.
Study of Piezo-Induced Surface Vibration in Solids Using Atomic Force Probe
Authors: Li Fang Hao , Zhang Dong Xian , Zhang Hai Jun
Published: July 2013

Piezo-induced surface vibrations in solids with nanometer amplitude are detected and analyzed. The vibrations are excited by the piezo element using a PZT component, which attached to the target material and controlled by a signal generator. The detections of such vibrations are carried out using the atomic force probe (AFP). The AFP is a very sensitive instrument utilizing a nano-tip connected to a cantilever to detect vibrations through an interaction of atomic force between the tip and the target surface with sub-nanometer resolution, about 30 times more precise than the piezoelectric sensor for the same signal detection. The glass material has been chosen as the target solid. The enhancement effect of the vibrations in the glass slice around resonance frequency is confirmed, the maximum amplitude appears at 7.4 kHz. The piezo-induced vibration will be employed in our future research for developing piezo-induced and laser-induced surface acoustic wave (SAW) motor.
The Fabrication of Silicon Nanopin with CsCl Nanoislands and Dry Etching for Field Emission
Authors: Ashmkhan Marina , Liu Jing , Wang Bo , Yi Fu Ting
Published: July 2013

Silicon nano pin arrays with heights of 1.3-3.66um and diameter of 315-899nm, are fabricated by CsCl self-assemble for CsCl nano islands for mask and ICP etching for silicon pins. CsCl film is firstly deposited on the wafer by thermal evaporation and putted in the humid controlled environment to be developed to the CsCl islands with diameter of 341-915 nm as self-assembled technology. Then the ICP etching with SF6, CCl4, He gas is introduced to make the silicon nano pin by the mask of CsCl nano islands, and the silicon nano pins with the different height of 1.3-3.66 um are finished for field emission. The gated FEA templates are fabricated by photolithography process and the lift-off technology with Ti-Si film as the gate electrodes. The final template for field emission has the silicon nano pins with diameters of 31.7 nm on top, Ti-Ag film with thickness of 105nm and gate holes of 30um in diameter, and SU8 resist insulator structure with thickness of 4um and holes of 10um in diameter. The optimization of the fabrication process and the performance for the configuration will be made.
The Omnipolar Integrated Magnetic Switch Based on GMR
Authors: Zhu Hua Chen , Qian Zheng Hong , Bai Ru , Li Jian Ping
Published: July 2013

This paper presents the realization of omnipolar integrated magnetic switch based on GMR sensor, which was integrated with a specifically designed process IC by SiP technology. This integrated switch introduced hysteresis and adjustable sensitivity to improve its performance. When the gain was set to 2, its operation point and release point are 2.7|Oe| and 1.8|Oe| respectively. Its characteristics and function are verified by 2D Helmholtz coils and gear sensor test platform.
The Reliability of Micro-Spring under Dynamic Circumstances
Authors: Lou Wen Zhong , Liu Peng , Li Kang , Ding Xu Ran
Published: July 2013

This article mainly focuses on the reliability of micro-spring, which as a typical component of MEMS device, applies electrodeposited nickel material and is fabricated by LIGA process, being used under the circumstances like transporting and restoring which may induce shock and crash. Griffith theory of brittle fracture and Abaqus FEA simulation software are applied for analyzing the probable failure modes of the micro-spring as overloaded. And the principle of elastic deformation, energy-time and displacement-time variation curves are given by three groups of simulation experiments. It proves to be one novel method to evaluate the reliability and accelerate exposing the failure mode of these MEMS components under dynamic circumstances in short period. After comparison, this method is proved reliable for analyzing and providing evidence for enhancing the reliability of the micro-spring, also improving the performance in micron size.
The Study of Free-Standing Diamond Film SAWF
Authors: Hu Dong Ping , Feng Jie , Tang Li
Published: July 2013

Surface Acoustic Wave Filter (SAWF) is widely applied in military and civil fields as Radar, Broadcast, Television, etc. The SAWF that the central operating frequency exceeds 1 GHz is one of the key elements in modern high frequency communication system. In this paper, on the free-standing diamond film and silicon wafer substrates, two kinds of SAWF are manufactured. Based on the same IDT structure that the interdigital width is 3μm, the center frequency of ZnO/diamond structures can reach to 1.03 GHz, while the ZnO/Si structures is 120 MHz. The result express that the SAWF on the base of diamond can work in high frequency mode, while the Insertion Loss is high, reach to 23dB.
A Single Cells Patterning Approach for Human Promyelocytic Leukemia Cells
Authors: Ren Da Hai , Cui Ming Yang , Wang Jun , Xia Yi Qiu , You Zheng , Wang Yin Ye
Published: July 2013

To get the detailed information of single cells and screen drugs effectively, especially to develop anti-cancer drugs in view of the cellular heterogeneity of tumors, biochips on single-cell level are necessary. Based on the fabrication techniques of MEMS, substrates with areas of hydrophilicity and hydrophobicity were fabricated to pattern single cells. The optimal process parameters for substrates fabrication are obtained through a series of experiments. MEMS substrates with clear binary surface patterns of hydrophilicity and hydrophobicity are achieved and a general streptavidin template with high bio-compatibility was prepared. In the experiment, biotin-BSA was employed as adhesive proteins Followed by streptavidin and biotinylated antibodies. An array of single HL-60 (Human Promyelocytic Leukemia Cells，HL-60) cells was obtained based on above protein adsorption substrate. The factors affecting the result of the single-cells patterning were investigated and optimized, by which a relatively high patterning rate is achieved. To keep cells characteristics and also for the future parallel patterning of different cells, specific antibodies are investigated for the cell HL-60, including CD45 and CD15. The result of antibodies immobilization and patterning are presented, which can well match the designed template.
Antifouling Performance of Surface Microtopographies Based on Sea Star Luidia quinaria
Authors: Zheng Ji Yong , Lin Cun Guo , Zhang Jin Wei , Wang Li , Xu Feng Ling , Zhou Juan , Duan Dong Xia , Liu Hui Hui
Published: July 2013

The surface microtopographies of the sea starLuidia quinariawere investigated and measured by 3D video microscope and scanning electron microscope. The antifouling effectiveness of biomimetic microtopographies based on sea star surface was evaluated using diatoms.
Capture of Charged Polymer in Salt Solution
Authors: Wei Xiao Long , Sha Jing Jie , Chen Yun Fei
Published: July 2013

To understand the capture of charged polymer in salt solution, we investigated the effect of the temperature, concentration of DNA molecules and electrical field to the polynucleotide capture rate by using a single graphene nanopore. From the result of the molecular dynamics simulations, it suggested that the capture rate becomes higher with increasing temperature and that it increases exponentially with the electrical field, and that low and high concentration of the polymer do not exhibit optimal capture rate. By analyzing the simulations results we predict that the capture rate is related to the aperture and the structure of the pore.
Preparation of PEI-Fe3O4/Survivin-siRNA Magnetic Complex and its Anti-Tumor Effect Combined with MFH on Lung Carcinoma Cells
Authors: Hou Xin Xin , Zhang Hao , Li Hong Bo , Yuan Chen Yan , Lin Mei , Ni Hai Yan , Zhang Dong Sheng
Published: July 2013

Objective: To prepare and characterize the PEI-Fe3O4 nanosized magnetic complex and investigate the therapeutic effects of the PEI-Fe3O4 /survivin-siRNA magnetic complex combined with magnetic fluid hyperthermia (MFH) on human lung carcinoma cells . Methods: Fe3O4 magnetic nanoparticles (MNPs) were prepared by the technique of chemical co-precipitation and the surface of Fe3O4 MNPs was modified by PEI. Transmission electron microscope(TEM)，X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR) were applied to characterize the PEI-Fe3O4 magnetic complex. Thermodynamic test was used to observe temperature change of various concentration of Fe3O4 suspension under alternating magnetic field(AMF). The DNA binding efficiency of PEI-Fe3O4 was observrd by electrophoresis experiment. Transfection efficiency was determined by delivering reporter gene(pEGFP-encoding luciferase)to GLC-82 cell lines using PEI-Fe3O4 as a vector. Inhibitory effect of the expression of survivin mRNA in GLC-82 cells was detected by RT-PCR after transfection with PEI-Fe3O4/survivin-siRNA. The therapeutic effects of PEI-Fe3O4/survivin-siRNA combined with MFH on GLC-82 cells was evaluated by MTT test. Results: The prepared Fe3O4 MNPs and PEI-Fe3O4 magnetic complex were approximately spherical，high electron dense，good dispersibility uniform in size observed by TEM, with an average diameter of about 20 nm.The XRD pattern of the sample showed the characteristic peaks of their cubic spinel structure,The observed diffraction lines were found to correspond to those of a standard ferrite(Fe3O4) pattern. The results of FTIR demonstrated the adsorption effect of PEI. The corresponding suspension with different concentrations of Fe3O4 MNPs could rise to a steady temperature ranging from 42°C～59°C under AMF within 40 minutes and keep stable from then on. The PEI-Fe3O4 magnetic complex had good binding ability with DNA which could efficiently deliver the foreign gene to GLC-82 cell.Inhibitory ratio of survivin mRNA expressions by survivin-siRNA was 35.6%and MTT test assay showed that the cell growth inhibition rate(IR) of the combination therapy(58.71%) is higher than that(31.87%,28.45%) of the single therapy. Conclusion: The experiment results suggested that PEI-Fe3O4 magnetic complex was an novel non-virus gene vector, which has multiple benefits in combination of thermotherapy and gene therapy on lung carcinoma.
Simulations and Experimental Studies on Biomolecules Passing through Polycarbonate Ultrafiltration Membrane
Authors: Liu Lei , Hou Yao Zong , Wu Ying Dong , Ni Zhong Hua , Chen Yun Fei
Published: July 2013

Nanopore and nanopore based biosensing and DNA sequencing have attracted more and more interests in the past ten years. In this paper, a simplified model is addressed to depict biomolecules passing through ultrafiltration membrane (containing nanopores). Based on this model, the passing velocity of biomolecules will not increase continuously but first increase, then decrease and stabilize with the IgG concentration increasing. Due to the physical place-holding effects and the simulation results, it can be predicted that, with biomolecules concentration increasing, the ionic current will first decrease, then increase and finnally stabilize. These predictions based on the simulation match our experimental results well.
Smart Structural Health Monitoring Based on Detecting Picometer-Scale Wavelength Shift of Fiber Bragg Grating
Authors: Bai Jun Jie , Li Jian Xing , Zhang Jun , Zhang Xiao Yun , Wang Le , Wu Ying
Published: July 2013

The real-time monitoring technologies of smart civil structure based on detecting picometer-scale wavelength shift of fiber Bragg grating (FBG), including the wavelength demodulation technology of FBG, are researched extensively at home and abroad. In the paper, using the technologies of wavelength division multiplex (WDM) and time division multiplex (TDM), fiber Bragg grating (FBG) sensor network was built for monitoring smart structure health condition. Based on SOPC (System on Programmable Chip) technology and fiber comb filter, a high-speed and high-precision wavelength demodulation scheme of FBG sensor network was proposed. The optical system and hardware circuit for demodulation system were designed specifically. To improve the accuracy of demodulation system of FBG, a constant temperature channel of the demodulation system connected with a fiber comb filter, which offered reference points to calibrate the Bragg grating center wavelength. Based on 32-bit soft-core processor NoisⅡ, the embedded system collected and processed the photoelectric signal voltage transformed to rectangular voltage pulse. The upper computer displayed dynamically the FBG wavelength demodulation process and calibrated the Bragg grating center wavelength. The experiments of FBG wavelength demodulation and health monitoring of smart structural embedded fiber Bragg gratings were done. Experimental results show that, the FBG wavelength demodulation method can be used to demodulate the FBG wavelength with high speed and high precision (± 2 pm), which can be used extensively in large-scale multipoint monitor engineering, and the strains of the smart structure can be measured accurately.
Synthesis of Biomorphic Ceria Templated from Crucian Fish Scales
Authors: Chen Feng , Chen Zhi Gang , Liu Cheng Bao , Wu Zheng Ying , Lu Qiu Yue , Yu Lei
Published: July 2013

Biomophic ceria with nanocrystalline was successfully synthesized using crucian fish scales as template. Unique biomorphic microstructures were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM) and nitrogen absorption-desorption technique. The obtained ceria material shows the repetitious biomimetic structure consisting of sheet with thickness of ca. 80-100 nm and nanopores which had 2-10 nm apertures. The surface oxygen activity of fish scale-templated CeO2 was enhanced revealed by hydrogen temperature-programmed reduction (H2-TPR) mesurements, because of the higher surface area (113.5 m2/g) and smaller particle size (average of 8.2 nm). Those detailed investigation could infer that the biotemplate product exhibit better catalytic activity in CO oxidation reaction.
Influence of Package on Micro-Accelerometer Sensitivity
Authors: Li Ping , Gao Shi Qiao , Jin Lei , Liu Hai Peng , Shi Yun Bo
Published: July 2013

Package is one of the key technologies for micro-accelerometer. This paper researched the influence of package on the sensitivity of self-designed piezoresistive accelerometer. Based on the designed package method, the effect of thickness and elastic modulus of die adhesive, package shell materials and signal connection wires on the sensitivity of the sensor were studied by theory analysis, simulation and experimental test. According to results, the sensitivity of micro-accelerometer would be increased with the increasing thickness of die adhesive and decreased with increasing elastic modulus and the quantity of the die adhesive; besides, compared with accelerometer packaged by ceramic shell, the sensitivity of accelerometer packaged with the stainless steel shell was much bigger; meanwhile, the output sensitivity of the sensor varied with length of signal connection wire.
MEMS Monolithic Integration Technology
Authors: Zhang Zhao Yun , Shi Zhi Gui , Yang Zhen Chuan , Peng Bo
Published: July 2013

The monolithic integrated technology of MEMS was discussed. First discussed the advantages and difficulties faced by the MEMS monolithic integration technology. Second the features and the process of the mainstream MEMS monolithic integration technology was introduced. And finally put forward a SOI MEMS monolithic integration technology, the technology with no high-temperature process, Post-CMOS integrated solution, compatible with the CMOS process. This technology can achieve high aspect ratio, high-performance micro-inertial devices..
New Structure of Crossing Magnetic Poles on Magnetic Fluid Seals
Authors: Zhao Meng , Jiang Shan Lin , Liu Cheng Jun
Published: July 2013

In order to improve the ability of magnetic fluid seals, the new structure of crossing magnetic poles on magnetic seals can be designed. The reluctivity of gap with the crossing magnetic pole is less than the reluctivity of gap without the crossing magnetic pole. The magnetic intensity in the gap can be bigger because of the crossing magnetic poles. According to the pressure formula of magnetic fluid seals, the pressure on the one side of magnetic fluid seals can be increased. The sealing capacity with the crossing magnetic pole is more than the sealing capacity without the crossing magnetic pole. The sealing capacity can be improved by 10%-15%.
The Study of Glass Cutting Based on the Micro-Crack Control
Authors: Huang Chao , Chen Ji Min , Yuan Jian Wen
Published: July 2013

A 532nm Diode-Pumped green laser was used to cut glass with the Micro-Crack control. The Micro-Crack was the micron-sized round-like crack caused by laser in the glass and the line-crack around the round-like crack. This paper researched the generation of the Micro-Crack and discussed how to control it, then researched the stress field in the glass during the cutting by finite element analysis. Propose a new method about the glass cutting which had advantages of low power, low heat effect, irregular-curve cutting and slant cutting.
Thermal Analysis of a Face-to-Back Bonded Four-Layer Stacked 3D IC Model
Authors: Du Xiu Yun , Tang Zhe Nan
Published: July 2013

Three dimensional integrated circuits (3D ICs) consisted of stacking and vertically interconnecting are an emerging technology with great potential for improving system performance. 3D integration relies on Through Silicon Via (TSV) interconnection and interlayer bonding between the silicon layers. Due to the advantages of higher device density, lesser signal delay, shorter interconnection length and smaller package size, this technology attracts growing attentions. A number of innovative processes contribute to the realization of 3D IC. These include back grinding, coating, cleaning, etching, wafer thinning, filling of high aspect ratio vias with electroplated copper and interlayer bonding, etc. In this work, finite element models for four-layer stacked TSV-based (Through Silicon Via) 3D IC are established based on the heat distribution of working process caused by heat source in device die, in order to investigate the thermal effects and determine the improvements required. The transient temperature fields of 3D IC structures are obtained. The effects of various geometric parameters and thermal properties on the overall temperature have been analyzed. The result indicates that TSV diameter, pitch, BCB thickness and BEOL conductivity play more important roles to the temperature increment and the maximum temperature of no TSV structures is several times of that of TSV-based structures. The copper provides for an effective heat conduction path, and reduces considerably the overall temperature. It is also shown that the heat path from chip to the bottom surface is the main way for the heat dissipation.
Characterization of Atmosphere PM2.5 and Dustfall in Xining (China)
Authors: Tang Jun , Dong Fa Qin , Dai Qun Wei , Deng Yue Quan
Published: July 2013

In this paper, mineral phase, elemental composition and size distribution were analysed by means of XRD, XRF and laser particle size analyzer respectively. According to the results of XRD, quartz, illite, calcite and albite were all found in three samples; Dolomite was found only in dustfall; Clinochlore was existed in both PM2.5 and soil. From the results of XRF, elemental compositon of three samples were focused on elemental Na, Si, Al, S, Ca, Fe, Mg, K. Based on the grain size analysis, the size distribution of dustfall mainly ranges from 1µm to 40µm.
Concentration Variation and Morphological Types of PM2.5 in Suburban of Yinchuan City
Authors: Chen Wu , Dong Fa Qin , Deng Yue Quan , Dai Qun Wei , Huang Yun Bi , Zhou Shi Ping
Published: July 2013

PM2.5 samples were collected by Desktop Aerosol Monitor Models 8530 and recorded the meteorological conditions in study site of Yinchuan City simultaneously. The daily averages of PM2.5 mass concentration varied from 0.134 to 0.222mg m3. The result shows that there are two apparent peaks of PM2.5 concentration in one day. Normally,PM2.5 mass concentration and temperature have some negative correlation. Their morphologies were determined by scanning electron microscopy (SEM). The particles were classified into four groups based on morphology. They were fly ash, mineral matter, irregular shaped mineral particle aggregation and other types. Fly ash and mineral matter were the two dominant types and fly ash is identified as originating from coal combustion or metallurgical plants, mineral matter from natural sources such as soil dust, resuspension of dust from roads.
Investigation on the Data Processing Method for High-Precision Alignment of PM Fibers
Authors: Rong Wei Bin , Zhang Wei , Wang Le Feng , Zhang Hai Ling , Sun Li Ning
Published: July 2013

The extinction ratio is the characteristic parameter of polarization-maintaining (PM) fiber couplers. The detection accuracy of polarization angle is related to the extinction ratio, and affects the thin-diameter PM fiber coupler performances greatly. A series of image processing steps including median filtering, adaptive image morphology, and maximum variance threshold segmentation method are used to get the outline of optical fibers. The minimum squares method is used to get the maximum intensity of the light. The experimental data is processed using the Fourier filtering method and influences of the manufacturing error and random errors of fibers are reduced. By fitting the experiment data with cubic spine method, and its mean square error of fitting is 0.05458, then the polarization angle of the PM fiber is determined. Experiments show that this method can precisely determine the fast axis position of PM fibers, and it can achieve the high precision alignment of 80 um PM fibers.
Research on the Gas Sensing Enhancement by Using CNT/ZnO Composites
Authors: Yu Ling Min , Fan Xin Hui , Shui Jing Yi , Qi Li Jun , Yan Wen
Published: July 2013

Multiwall carbon nanotubes (CNT) were added into ZnO matrix to develop a CNTs/ZnO composite gas sensor. The hybrid sensor is used to detect CO in air by measuring resistance changes of thin CNTs/ZnO films at different working temperature. For comparison, pure ZnO and CNT/ZnO sensors are also examined. The gas sensing results reveal that CNTs/ZnO with the weight ratio (9:100) hybrid sensors exhibit much higher sensitivity and fast response-recovery properties towards CO, at 240°C than the blank ZnO nanowires. Hybrid material of ZnO nanowires and CNT composites could potentially display not only the unique properties of nanowires and those of CNTs, but also an additional novel property.
Study on Active Vibration Control
Authors: Xing Feng , Cao Jian Guo , Wang Jing , Deng Chang Yong
Published: July 2013

This paper analyses the active vibration control technology on the piezoelectric ceramics car-body pieces in fuzzy control Strategy. Adaptive controllers, based on fuzzy logics, are synthesized for the control of vibration of body structure. Piezoelectric element, control system and body structure have been combined to be a intelligent response system to external drive and it’s own vibration. This system can effect reducing body structure’s reaction from environmental load with external energy. The availability of the control strategy has been confirmed by experiments.
Ultrasonic Attenuation of High Concentration of Micron Particle Clouds
Authors: Guo Ming Ru , Lou Wen Zhong , Liu Yan Kun , Wang Fu Fu , Ding Xu Ran
Published: July 2013

This paper presents the simulation and experiment about the attenuation characteristics of ultrasound in micron particle clouds. Firstly, several models that have been used in the suspension concentration measurement are analyzed. Then the numerical simulations are conducted to try to establish the relationship between the consciousness, particle size and the frequency. Finally, an experiment is conducted to verify whether the attenuation of ultrasound in micron particle clouds follows the simulations' relusts. The results of numerical simulations and the experiment both show that the intensity of ultrasound has a positive correlation with the consciousness, but the relationship between the attenuation and particle size is still uncertain for lack of experimental data. At present, research is still in ongoing.
Uncatalyzed Oxidation of Cyclohexane in the Microchannels
Authors: Wang Lei , Zhu Ming Qiao , Lu Jian Gang , Hu Hong Ding
Published: July 2013

The oxidation of cyclohexane in the microchannels not only improves the safety of the reaction, but also the performance of the oxidation reaction. Different gas-liquid micro mixers were used for the mixing of gas and liquid before entering into microchannels, and SIMM-V2 performed best of all. Excellent slug/plug flow can be formed in the microchannels after mixing in the gas-liquid micro mixer when the molar ratio of oxygen to cyclohexane is less than 0.5:1. The conversion of cyclohexane increased as the residence time increased, but the selectivity of cyclohexanol and cyclohexanone increased first and then decreased. At the reaction temperature of 200 °C, with the flow rate of the solvent isopropanol being 1 mL/min and the molar ratio of oxygen to cyclohexane being 0.15:1, both the conversion of cyclohexane and selectivity of cyclohexanol and cyclohexanone increased with the increase of pressure. The conversion of cyclohexane and selectivity of cyclohexanol and cyclohexanone reached 10.10% and 66.93% respectively at the pressure of 8 MPa. It is indicated that the new process by use of uncatalyzed cyclohexane oxidation in the microchannels will have very attractive prospects in the improvement of the safety, intensification of the gas-liquid mass transfer and obtaining good reactive performance. Therefore, the technology shows good potential in industrial applications.
Design of 6H-SiC High Temperature Pressure Sensor Chip
Authors: Ma Xi Min , Tang Fei , Wang Xiao Hao
Published: July 2013

Over the last decade, a relatively in-depth research on the different structures and types of the full SiC pressure sensors including the piezoresistive, the capacitive and the optical SiC pressure sensors etc. has been conducted with a view to realizing the pressure measurement in high temperature circumstances. The piezoresistive SiC pressure sensor has gradually become the focus of research due to its simple structure and convenience application. In our research, the piezoresistance strip is designed on the deep-etching sensitive circular diaphragm formed via deep etching. Firstly, the 6H-SiC strain coefficient GF value is compared on the radial direction and the transverse direction by analyzing the circular diaphragm deformation theory. It’s concluded that both in the radial direction, four resistance strips are assigned in the center of circular diaphragm and along the edge respectively, with equal number on these two locations. Better consistency and sensitivity are achieved by this solution. Secondly, the design size of the sensitive circular diaphragm and the pressure resistance strips are determined with the expected work temperature and the target measuring range being taken into consideration. The final layout scheme design of four pressure resistance strips is determined through simulation on the consideration of the thermal stress caused by the AlN packaging.
Microelectromechanical Hybrid Gyroscope Design of Closed-Loop Detection Circuit Based on FPGA
Authors: Xia Dun Zhu , Yu Cheng , Wang Shou Rong , Li Hong Sheng
Published: July 2013

This paper presents a new microelectromechanical hybrid gyroscope (MHG) with three equilibrium rings. This structure can eliminate the error caused by the double rotation frequency of the driving shaft successfully. The MHG kinematic equations with three equilibrium rings are derived in this paper. Meanwhile, a new digital design and simulation of the MHG closed-loop detection circuit are proposed based on FPGA. The noise interference is weakened by using differential mode signal detection and the resources of FPGA are decreased by the loop diode demodulation in this paper. The cross axis coupling of the decoupled system is about 2.4%. The phase margin is 70deg and the magnitude margin is 22db after correction. The transcient response simulation is tested when the inputs are sinusoidal functions. The bandwidth and scale factors of x-axis and y-axis closed loops are analyzed in the paper. The bandwidth can reach about 70Hz and the scale factors of x-axis and y-axis closed loops are 0.1467V/o/s and -0.1467V/o/s respectively.
Research on Zero Bias Characteristic of FBW Gyro
Authors: Zhong Lun Chao , Wang Jian Zhong , Duo Ying Xian
Published: July 2013

Zero bias is an important performance index of FBW gyroscope. Based on the given gyroscope experiments,we studied zero bias of random error properties,temperature characteristic, large overload environment variation, and then calculate FBW gyro bias, bias stability, zero bias repeatability.We use Kalman filter into FBW gyroscope for random error compensation.Through least-square method,we fit temperature scale factor and temperature bias of FBW gyro.The experimental results show that the compensation method has the advantages of simple operation,effectively compensation for measuring error of FBW gyroscope which is induced by temperature, and has strong engineering using value.
Projectile-Borne Meteorological Information Detection Dropsonde Integrating Micro-Sensors
Authors: Hong Rong Sen , Lou Wen Zhong , Guo Ming Ru , Liu Cheng Qi
Published: July 2013

The projectile-borne meteorological information detection dropsonde is designed to be launched by a missile and dropped at altitude as the missile reached its peak to detect real-time meteorological information as the device falls to the surface. The high acceleration shock deriving from missile launch, violent changes of atmospheric parameter and stochastic disruptions from external environment are the main difficult to design this device. To deal with those problems, we apply sensors based on MEMS technology as their high performance in accuracy, anti-overload and easy integration, we explore best locations on the dropsonde body for sensors based on simulation, we develop effective arithmetic for data processing. At last, the performance of dropsonde is verified by some ground static experiments.
Y-Type Branch Waveguide Used in Resonant Micro-Optic Gyro
Authors: Wang Jun Jie , Feng Li Shuang , Wang Wei , Liu Hui Lan , Li Ru Ya
Published: July 2013

Resonant Micro-Optic Gyro (RMOG) is a kind of optical sensors measuring angular velocity via Sagnac Effect, which yields different central resonant frequency between the clockwise (CW) and counterclockwise (CCW) light path of a ring-resonator when rotating. In this paper, Y-type branch waveguide is put forward to replace K-type coupler in RMOG to reduce the influence of splitting ratio asymmetry due to fabrication errors and temperature drift. Y-type branch waveguide based on silicon-on-silica is designed and analyzed. Simulation results show that Y-type branch waveguide performs better fabrication tolerance than K-type coupler, which reduces the nonlinear Kerr-Effect induced noise excited by power nonuniformity of the counter-propagating beams, therefore the detection sensitivity of RMOG can be improved.
Analysis of Intensity Variation of Laser in Resonator Micro-Optic Gyro
Authors: Lei Ming , Feng Li Shuang , Zhi Yin Zhou
Published: July 2013

The paper describes the basic principle and structure of the resonator micro-optic gyro (RMOG), the influence of intensity variation of laser is analyzed for the first time. The relationship between the light intensity input the integrated optical resonator (IOR) and the slope at working range is simulated and analyzed by the optical field overlapping method. The amplitudes of the output square waveforms with different zero biases are simulated and analyzed. The experimental setup is constructed and tested, the test result shows that in order to reach the limited ultimate sensitivity of 15.5 deg/h, it is necessary to restrict the zero bias within 8.1 deg/s under open-loop output scheme.
A Novel Noise Resistance Optical Accelerometer Based on Micro-Ring Resonant Cavity
Authors: Wang Xiao Qian , Yan Shu Bin , Ma Ke Zhen , Xu Peng Fei , Zhang Wen Dong
Published: July 2013

To meet a high-precision accelerometer resistance of temperature, humidity and other external noise, a new multi-ring cascade optical accelerometer structure is designed. The micro-ring resonator on the cantilever beam based on the photo-elastic effect and the contrast are fabricated with the same manufacturing process and size, which can effectively meet the consistency of the contrast and test micro-ring resonator on the cantilever. The one resonance point curve will split into two under the acceleration, thus the acceleration value can be obtained by detecting the wavelength of the two resonant points. By testing the cascade race-track shaped micro-ring resonator at different temperatures, the Q=104, the test requirement of cascade race-track shaped micro-ring accelerometer in different environments is greatly met. The design can be widely applied to the occasions of penetration system with high impact, strong vibration and so on. And the anti-noise and anti-jamming features of the integrated miniaturized high-sensitivity MOEMS sensors are realized.
The Design of a Membrane Biosensor
Authors: Sang Sheng Bo , Zhang Wen Dong , Feng Hui , Li Peng Wei , Hu Jie , Li Gang
Published: July 2013

The need for high throughput label-free multiplexed sensors for biological sensing has increased in the last decade. In this paper, a new surface stress-based polydimethylsiloxane (PDMS) membrane biosensor for cellular detection is designed and fabricated. The geometric parameters of the PDMS membrane are optimized through the finite element (FE) analysis. One fiber optic interferometer biosensor test system is built to test the characteristics of the biosensor. The biosensor is further functionalized using 11 Mercapto 1 undecanoicacid (MUA: SH-(CH2)10-COOH) and tested in contact with cells Escherichia coli (E. coli). The results of our experiments showed that cells can be detected based on the surface stress-based PDMS membrane biosensor. The new approach for cellular detection has good sensitivity and biocompatibility.
The Effect of Casimir Force to the Performance of the Micro-Accelerometer
Authors: Shen Li , Gao Shi Qiao , Guan Yan Wei
Published: July 2013

Casimir had measured the Casimir force through experimental methods, and fitted the empirical formula between the plates. On its basis we analyse that when the gap of two separating surfaces achieves submicron in micro devices, the effect of the Casimir force to the micro-devices is great and this Casimir effect can not be ignored. The results show that: Considering the Casimir force or not, the extreme value of acceleration which can be detected by micro-accelerometer is different, and we have got the specific numerical fitting figure by Matlab .
Research on Mean Filtering Algorithm in Resonant Micro-Optic Gyro Signal Processing Based on Labview
Authors: Zhang Yang Cheng , Feng Li Shuang , Ma Ying Jian , Zhi Yin Zhou , Lei Ming , Su Ni
Published: July 2013

As one of the new optical sensing devices, Resonant Micro-optic Gyro (RMOG) measures the rotation rate due to the resonance frequency difference based on the optical Sagnac effect. In order to reduce the influence of the light path and circuit noise and the output edge pulse signal, the mean filtering algorithm based on Labview is put forward to improve the gyros performance. The mean filtering algorithm is simulated and realized with Labview, which approves that the algorithm is effective in noise restraining. The test of RMOG demonstrates that the zero bias stability is 1.4 °/s during 1 hour with 10-second smoothing.
Effect of Adsorption Stress-Induced Change in Neutral Layer Position on Static Behavior of Microcantilever Gas Sensor
Authors: Wang Fei , Zhao Liang , Zhang Yan Ling , Jing Da Lei
Published: July 2013

The static bending model of microcantilever with monolayer molecules has been established based on energy method, in which the change in neutral layer position caused by adsorption-induced stress is introduced. On this basis, we have analyzed the relationship between the bending curvature radius of a microcantilever with its thickness, Young’s modulus and molecule-molecule distance of adsorbed molecules when it is adsorbed with monolayer water molecules. Additionally, we have investigated the effect of change in neutral layer position on the static behavior of microcantilever sensors. The results show that 1)the bending curvature radius of microcantilever is the linear, quadratic and eight approximation function of its Young’s modulus, thickness and distance of adsorbed molecules, respectively; 2)the predicted error of bending curvature radius caused by the change in neutral layer position slightly increases with decreasing Young’s modulus and thickness, whereas the effect of distance between adsorbed molecules on the error is significant; 3)the change in neutral layer position can cause a significant effect on the sensitivity and surface strain of the microcantilever
A Novel Structure of Polyimide-Based Humidity Sensor Used in Low Temperature Environment
Authors: Xiao Li , Zhao Zhan , Du Li Dong , Fang Zhen , Wu Shao Hua
Published: July 2013

In this paper, a new structure of polyimide-based humidity sensor is developed, which can work better at low temperature environment. In this humidity sensor, the capacitive part is sputtered on a suspended membrane, the lower electrode is also a controllable heater, used to control the temperature on the surface of the sensor through the external circuits. The results of experiment suggest that the sensor has a wide range of sensing ambient relative humidity from 10%RH to 90%RH with a controllable constant temperature and at a lower temperature it shows a good linearity.
Fabrication of Sub-Micro Metal Tips for In-Plane Field Emission Research
Authors: Wang Li Feng , Han Lei , Tang Jie Ying , Song Jing , Huang Qin Gan
Published: July 2013

Fabrication of a novel in-plane field emission diode structure is presented. Sub-micro metal tips were obtained using a two-step lithography method. The Minimum width of the metal tips was less than 100nm, and the minimum spacing of 145.7nm was obtained. The I-V characters in atmospheric environment before and after the silicon etching were measured.
Temperature Model for a Vacuum Packaged MEMS Gyroscope Structure
Authors: Cao Hui Liang , Li Hong Sheng , Lu Xu , Ni Yun Fang
Published: July 2013

The influence of temperature’s variation upon the resonant frequency and damping of the Micro-Electro- Mechanical-System (MEMS) gyroscope’s silicon structure in the vacuum package is investigated in this article. The gyroscope’s working principle and the dual-mass decoupled gyroscope structure are introduced, the drive and sense modes’ frequencies are analyzed. The ideal models of resonant frequency and damping are established and the dominate elements of impacting the resonant frequency and damping are Young Modulus, air viscosity coefficient and ambient pressure respectively. The experiments and the results proved that the frequency model works well, and the damping model only can simulate the tendency because of the air getter’s influence.
A Fourth-Order MASH Sigma-Delta Modulator in Inertial Sensors
Authors: Liu Xiao Wei , Li Qiang , Sun Guan Nan , Liu Wen Yan
Published: July 2013

The theory of a Sigma-Delta modulator is introduced in this paper. Based on this theory, a feedback 2-1-1 multi-stage-noise-shaping (MASH) sigma-delta modulator is designed, and the coefficients of the modulator are calculated. The system-level simulation results show that the effective number of bits (ENOB) is 24 bits when the signal bandwidth is 1 kHz and the over-sampling (OSR) rate is 128. Then the circuits of modulator are designed, including integrator, comparator, multi-phase clock and the noise cancelling logic. The whole modulator is simulated in Cadence, the signal to noise ratio (SNR) of the modulator is 125.4dB, and the ENOB is 21.1bits, which meet the technical requirements of the sensor.
Research on Micro Twin-Bridges Catalytic Combustion Type Kerosene Gas Sensor Technology
Authors: Wang Ping , Zhang Hong Quan , Zhang Tong , Wang Bo Ran , Wen Dian Zhong
Published: July 2013

Based on the principle of catalytic combustion type gas sensor, a kerosene gas sensor with micro twin-bridge structure is fabricated using silicon micromachining technology. A pair of platinum film resistor is fabricated by film processing, and its nominal resistance is 20Ω at 0°C. The nano-alumina catalytic carrier and noble metal catalyst are coated on the surface of sensitive resistance in order to form the sensitive bridge and compensating bridge. The monolithic integration of catalytic element and compensating element is achieved on the silicon micro twin-bridge for fabrication of kerosene sensor. The simulation result shows that once temperature of one bridge rises to 650K, the other bridge may increases about 10°C. The test on kerosene sensor by calibration device indicates that the sensor can detect the kerosene volume fraction ranging from 0 to 7000×10-6 and the sensor output property is linear.