Proceedings Volume 7510

2009 International Conference on Optical Instruments and Technology: MEMS/NEMS Technology and Applications

Zhaoying Zhou, Toshio Fukuda, Helmut Seidel, et al.
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Proceedings Volume 7510

2009 International Conference on Optical Instruments and Technology: MEMS/NEMS Technology and Applications

Zhaoying Zhou, Toshio Fukuda, Helmut Seidel, et al.
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 20 November 2009
Contents: 4 Sessions, 22 Papers, 0 Presentations
Conference: International Conference on Optical Instrumentation and Technology 2009
Volume Number: 7510

Table of Contents

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Table of Contents

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  • Front Matter: Volume 7510
  • Session 1
  • Session 2
  • Poster Session
Front Matter: Volume 7510
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Front Matter: Volume 7510
This PDF file contains the front matter associated with SPIE Proceedings Volume 7510, including the Title Page, Copyright information, Table of Contents, the Conference Committee listing and introduction.
Session 1
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Tunable RF MEMS capacitor for wireless communication
Xiuhan Li, Yu Xia, Jian Liu, et al.
High quality tunable MEMS parallel plate capacitors have been widely used in phase shifters, oscillators and tunable filters for wireless communication. As electrostatic actuation and air dielectrics have led to devices with low power consumption and high quality factors, an electrostatically actuated MEMS tunable capacitor with two flexible plates have been designed and fabricated in this paper. According to the measurement results, tunable capacitor shows good performance in the frequency range of 2GHz-10GHz. The pull-in voltage for the capacitor is 13 V. The tuning ratio of the capacitor is very high, which can reach 320%.
Mechanical design and system-lever analysis of a novel micromirror array
Quan Sun, Ming Cai, Ningyuan Wang, et al.
A novel micromirror array based on PolyMUMPs fabrication process is proposed and explored. The segmented array described here, consisting of 37 hexagonal mirrors with diameter of 380um, is fabricated by MEMSCAP. A hierarchical design and optimization of the opto-mechano-electrical structure was carried out, combining finite element analysis (FEA) performed in Comsol Multiphysics with a system-level macromodelling in Matlab. The micromirror prototype uses design techniques able to provide a low pull-in voltage (less than 10V with all three electrodes biased and less than 14V with only one biased electrode) and large strokes (about 3um), as revealed from both FEA and system level simulation. Preliminary experimental test results show that the individual micromirrors can be actuated and orientated in space by applying voltages on their actuation electrodes. Following the individual micromirror cells tests, the entire array will be integrated in an adaptive microsystem for wavefront correction.
Out-of-plane vibration measuring technique based on dynamic AFM
Lin-yan Xu, Long Ma, Xing Fu, et al.
The theory modal of dynamic AFM probe under vibration surface and also the corresponding normalized form are set up, while the frequency range of the out-of-plain vibration of the sample (i.e. the frequency ratio of the sample vibration frequency and the probe's working frequency in the normalized form) that dynamic AFM can measure is the most important to analyzed. Runge-Kutta numerical method is used to analyze the feasibility and the bandwidth of AFM vibration measuring technique. Taking fixed-fixed nanobeam resonator under electrostatic actuation as the measured sample, its out-of-plane amplitude frequency response characteristics are measured using micro-laser Doppler vibrometer (microLD), scanning tapping mode (TM) AFM and force-curve tapping mode (F-TM) AFM respectively. The accordant resonant frequency of 1.73 MHz are gained and the vibration-amplitude test results have small deviations. The frequency speciality of vibration measurement errors of dynamic AFM related with the quality and strength of the vibration sample is strongly put up.
A simulation of dielectrophoresis force actuated liquid lens
Xiaoyin Yao, Jun Xia
Dielectrophoresis (DEP) and electrowetting on dielectric (EWOD) are based on the electrokinetic mechanisms which have great potential in microfluidic manipulation. DEP dominate the movement of particles induced by polarization effects in nonuniform electric field ,while EWOD has become one of the most widely used tools for manipulating tiny amounts of liquids on solid surfaces. Liquid lens driven by EWOD have been well studied and developed. But liquid lens driven by DEP has not been studied adequately. This paper focuses on modeling liquid lens driven by DEP force. A simulation of DEP driven droplet dynamics was performed by coupling of the electrostatic field and the two-phase flow field. Two incompressible and dielectric liquids with different permittivity were chosen in the two-phase flow field. The DEP force density, in direct proportion to gradient of the square of the electric field intensity, was used as a body force density in Navier-Stokes equation. When voltage applied, the liquid with high permittivity flowed to the place where the gradient of the square of the electric field intensity was higher, and thus change the curvature of interface between two immiscible liquid. The differences between DEP and EWOD liquid lens were also presented.
Detection system of capillary array electrophoresis microchip based on optical fiber
Xiaobo Yang, Haiming Bai, Weiping Yan
To meet the demands of the post-genomic era study and the large parallel detections of epidemic diseases and drug screening, the high throughput micro-fluidic detection system is needed urgently. A scanning laser induced fluorescence detection system based on optical fiber has been established by using a green laser diode double-pumped solid-state laser as excitation source. It includes laser induced fluorescence detection subsystem, capillary array electrophoresis micro-chip, channel identification unit and fluorescent signal processing subsystem. V-shaped detecting probe composed with two optical fibers for transmitting the excitation light and detecting induced fluorescence were constructed. Parallel four-channel signal analysis of capillary electrophoresis was performed on this system by using Rhodamine B as the sample. The distinction of different samples and separation of samples were achieved with the constructed detection system. The lowest detected concentration is 1×10-5 mol/L for Rhodamine B. The results show that the detection system possesses some advantages, such as compact structure, better stability and higher sensitivity, which are beneficial to the development of microminiaturization and integration of capillary array electrophoresis chip.
Session 2
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A novel evaluating method for the MEMS-based uncooled IR system
An experiment using 4f system model is designed to test the consistency of the units on the FPA , which is made based on MEMS technology. An optical stop as a filter is set at the back focal plane of the first lens. We get each image where the light source locates when it is rotated round FPA. The size of the stop and the rotating angle can be deduced according to the parameters of two lens. Meanwhile reflectance spectrum of each unit on the FPA can be drawn with the gray level of the image presented by CCD. Contourgraph is used to test the displacement deflection value caused by thermal deformation of FPA. According to the displacement deflection value and the unit size of FPA, we get the average deflection angle of FPA's units when temperature changes per centigrade degree. We can define a gray level difference of two adjacent images at the same position as M. When we let the value of M larger than a number N, we can say that the system has met the requirement of temperature sensitivity-T. With the help of M, light rotating angle and FPA's deflection angle, we can get the temperature sensitivity of the IR system. The actual value of temperature sensitivity approximates the NETD of the system. The calculating process proves that it can estimate the NETD, if we don't want to get the accurate value of NETD. The expression of T is much easier and more feasible than that of NETD.
Optimal algorithm to improve the calculation accuracy of energy deposition for betavoltaic MEMS batteries design
Sui-xian Li, Min Sun
Aimed at improving the calculation accuracy when calculating the energy deposition of electrons traveling in solids, a method we call optimal subdivision number searching algorithm is proposed. When treating the energy deposition of electrons traveling in solids, large calculation errors are found, we are conscious of that it is the result of dividing and summing when calculating the integral. Based on the results of former research, we propose a further subdividing and summing method. For β particles with the energy in the entire spectrum span, the energy data is set only to be the integral multiple of keV, and the subdivision number is set to be from 1 to 30, then the energy deposition calculation error collections are obtained. Searching for the minimum error in the collections, we can obtain the corresponding energy and subdivision number pairs, as well as the optimal subdivision number. The method is carried out in four kinds of solid materials, Al, Si, Ni and Au to calculate energy deposition. The result shows that the calculation error is reduced by one order with the improved algorithm.
Analysis of cylindrical subwavelength diffractive optical elements by an approximate vectorial diffraction method
Jia-sheng Ye, Yan Zhang
Vectorial diffraction methods provide accurate analysis of subwavelength diffractive optical elements, but they usually consume a lot of computing time and computer memory. On the other hand, scalar diffraction methods have simpler physical models and cost much less computer resources at the expense of a large numerical error. Therefore, an approximate method is highly required, which can substantially relieve the computational burden and possess a high accuracy. We firstly propose such an approximate vectorial method, i.e., the improved first Rayleigh-Sommerfeld method (IRSM1), and apply it to analysis of two-dimensional (2-D) cylindrical microlenses and metallic cylindrical focusing micromirrors. The IRSM1 is clearly proved to be much more accurate than the scalar diffraction method. In addition, compared with the vectorial boundary element method, the IRSM1 consumes much less computing time and computer memory. Besides of the above, the IRSM1 is expected to be used in optical designs of subwavelength diffractive optical elements by incorporating with the simulated annealing method or the Yang-Gu algorithm.
Poster Session
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Study on electroforming Ni-Fe alloy microstructure
Xiaohu Zheng, Yuanwei Liu
The relationship between the composition, coating microstructure and electromagnetic properties of electroforming Ni-Fe alloys was studied in this paper. And the optimal process parameters to obtain Ni-20%Fe deposition was as following: FeSO4·7H20 concentration was 6g/L; PH value of the solution was 2.5; current density was 3.5A/dm2; electrolyte temperature 55. The results indicate that the Ni-Fe deposit is bright and compact, the crystalplanes of the plating were (111), (220) and (200). Electrodeposited Ni-20%Fe has a strong paramagnetism effect with the smallest remanence of 0.5 emu, The coercivity show a monotonic decrease with increasing Fe content in deposit, and the saturation magnetization was only 10% of that of the IJ85 permalloy, which proved that the electroformed Ni-20%Fe alloy has good electromagnetic property and could be used in MEMS actuator manufacturing.
Study of SiNx thin film character with gas flow rate in PECVD
Zhe Kang, Weizhi Li, Yadong Jiang
Elements distribution, refractive index (RI) and stress of silicon nitride (SiNx) thin film under different gas flow rate conditions of plasma enhanced chemical vapor deposition (PECVD) was studied. Infrared spectrum, RI and stress of SiNx thin film were measured by infrared spectrometer, ellipsometer and stress instrument, respectively. Results showed that SiNx thin film had the lowest hydrogen Element when silane-ammonia flow rate was 1/4, and increase the flow rate of either gas would lead to more corresponding element (i.e. N in ammonia, Si in silane) and hydrogen bonds in deposited films. RI of thin film was decided by the content of nitrogen and silicon. Deposition mode was the most important factor in determining the stress of SiNx film, while in the gas-flow-rate-limited mode the stress was also lightly impacted by the content of hydrogen in the film.
The real-time infrared image denoising method of double buffering for microcantilever-based infrared imaging system
Cheng Gong, Mei Hui, Liquan Dong, et al.
Micro-electro-mechanical system (MEMS) thermal transducer is a promising technological platform for uncooled IR imaging. We fabricated MEMS infrared focal plane arrays (FPA) based on bi-material micro-cantilever and built an optical-readout infrared imaging system. However as a result of some factors there are a great many of noise in the infrared images. This paper presents a meaningful real-time denoising method base on double buffering. The advantages of this method are not only solving the problem of fluency for real-time infrared image processing, but also improving the noise problem impacting on the quality of infrared imaging. We have applied it to optical-readout infrared imaging system successfully. We present this method and our results in the paper.
Reactive Ion Etching of Al-1%Cu alloy thin films
Jun Gou, Zhi-ming Wu, Hui-ling Tai, et al.
The special technical process was demaned for the reactive ion etching (RIE) of AlCu alloy thin films, such as the removal of doped Cu, the protection of sidewall and the prevention of chlorine corrosion after etching. In this paper, Al-1%Cu alloy was etched using BCl3, Cl2 and N2 gases, and CH4 was also added in the etching gases in order to enhance the sidewall protection. The process was optimized and the multi-step process were abtained. The effect of CH4 on sidewall protection was analyzed. The removal of residue after the etch was also studied.
Design and simulation of tunable micromirror for two-color microbolometer
Yuguang Gong, Wei Li, Haihong Cai, et al.
A tunable reflecting micromirror made up of two layers of Al and Si3N4 is designed to suspend between the silicon substrate and the heat sensitive membrane for measuring the actual temperature and color of an object based on comparison of two wavelength response windows, 3-5 μm and 8-12 μm. The micromirror, switching between two positions by an applied electrostatic voltage, provides a response to two wavelength windows by tuning the optical tunable resonant cavity. With different distances between the micromirror and the bottom electrode, the total capacitance of the tunable micromirror is gained based on electromagnetic analysis and theoretical equation. The pull-in voltage is calculated as 8.21 V by electrostatic-mechanical coupling analysis. But if the voltage is increased to about 9.73 V, the micromirror will touch the bottom electrode by pull-in behavior. At last, the vibration modes of the tunable micromirror are simulated using ANSYS, and the fabrication process flow of the two-color microbolometer is theoretically demonstrated.
Simulation and optimal design for deformable mirror supporting structure
Fu Zhao, Ping Wang, Yanjue Gong, et al.
This article takes a kind of special supporting structure of deformable mirror as an example to make deeply study on its optimal design and validity simulation based on finite element analysis. The original resonance frequency and modes shape of the supporting structure are obtained with the FEA method and the dynamic theory. Then a group of optimized structure parameters are determined with the BP networks and Genetic Algorithm optimal methods. The simulation analyses including random vibration, harmonic response and fatigue life are carried out to demonstrate that the dynamic stiffness of the optimized supporting structure has been improved greatly by the presented optimization method.
Influence of PECVD process parameters on the etching Rate of SiN[sub]x[/sub] films
Jun Gou, Zhi-ming Wu, Hui-ling Tai, et al.
Silicon nitride (SiNx) thin films were deposited by plasma-enhanced chemical vapor deposition (PECVD) with different process parameters (frequency, the ratio of SiH4 to NH3 gas, and the gas composition), and reactive ion etching (RIE) experiments of these SiNx thin films were carried out in order to research the relationship between PECVD process parameters and the etching rate (ER). The SiNx film properties (density, film composition and refractive index), which affected the etching rate, were also studed.
An analysis on the urban spatial expansion of Hangzhou based on remote sensing
Qianhu Chen, Chudong Huang
Hangzhou is in the contradictory trouble of lacking and wasting land resources. Although there has been some research on urban spatial expansion, most of them are on the stage of expressing the concept because of lacking comprehensive and quantitative analysis technology. This paper introduces remote sensing techniques to analyze the urban spatial expansion of Hangzhou city. The research generally consists of 3 steps: 1) to retrieve the urban area in each year using synthetic methods of supervised classification and visual interpretation; 2) to compare the total area and the corresponding data of population and economy, and to analyze the intensivism of urban land use; 3) to analyze the urban spatial expansion of Hangzhou according to the intensivism. It is learned that the urban land use in Hangzhou from the year 1978 presents the characteristic of "circles". The urban area of present Hangzhou could be divided into 3 circles, representing the urban land use in sprout, developing and stabilizing and optimizing stages, and reflecting the real and overall process of space-growth in Hangzhou. Some suggestions for urban planning and urban land use are accordingly given in the following part.
Effect of different support structures on the characteristic of the grating light modulators
Wei Wei, Weiming Chen, Yong Zhu, et al.
The energy method is applied in the analysis of the elastic coefficients of the crab-leg beam and the guided-end beam under the micro-nano-scale, the theoretical formula of the elastic coefficient is got. By considering the elastic coefficient caused by the residual stress and the edge effect of the capacitors, the static electrical and mechanical model of the grating light modulators is established. According to the static electrical and mechanical model and the actual design parameters, the pull-in voltage of the GLM with crab-leg beam is 7.2 V and the pull-in voltage of the GLM with guided-end beam is 9.5 V. The experimental system is built to test the performance of the grating light modulator. By using this experimental system, the pull-in voltage of the GLM with crab-leg beam is 7.6 V and the pull-in voltage of the GLM with guided-end beam is 10.2V.
Kernel regression image processing method for optical readout MEMS based uncooled IRFPA
Liquan Dong, Xiaohua Liu, Yuejin Zhao, et al.
Almost two years after the investors in Sarcon Microsystems pulled the plug, the micro-cantilever array based uncooled IR detector technology is again attracting more and more attention because of its low cost and high credibility. An uncooled thermal detector array with low NETD is designed and fabricated using MEMS bimaterial microcantilever structures that bend in response to thermal change. The IR images of objects obtained by these FPAs are readout by an optical method. For the IR images, one of the most problems of fixed pattern noise (FPN) is complicated by the fact that the response of each FPA detector changes due to a variety of factors. We adapt and expand kernel regression ideas for use in image denoising. The processed image quality is improved obviously. Great compute and analysis have been realized by using the discussed algorithm to the simulated data and in applications on real data. The experimental results demonstrate, better RMSE and highest Peak Signal-to- Noise Ratio (PSNR) compared with traditional methods can be obtained. At last we discuss the factors that determine the ultimate performance of the FPA. And we indicated that one of the unique advantages of the present approach is the scalability to larger imaging arrays.
1-dimension nano-material-based flexible device
Xing Yang, Zhaoying Zhou
1D nano-material-based flexible devices has attracted considerable attention owing to the growing need of the high-sensitivity flexible sensor, portable consumer electronics etc.. In this paper, the 1D nano-materials-based flexible device on polyimide substrate was proposed. The bottom-up and top-down combined process were used for constructing the ZnO nanowire and the CNT-based flexible devices. Their electrical characteristics were also investigated. The measurement results demonstrate that the flexible device covered with a layer of Al2O3 has good ohm electrical contact behavior between the nano-material and micro-electrodes. The proposed 1D nano-material-based flexible device shows the application potential in the sensing fields.
Analysis and modeling of thermal failure based on a MEMS thermally driven structure
Xiuhan Li, Quan Yuan, Leijie Lang, et al.
This paper presents an analysis of the thermal failure model of a MEMS thermal driven structure fabricated by MetalMump process. The finite element analysis was used to study the thermal electrical model and the experimental test results were compared with the simulated results. The parameters of the driven current applied on the structure which influence the system stability were considered, including the current value as well as the frequency. Avoiding thermal aggregation leading to structure destruction, the geometry factors of the structure design were also discussed to improve the heat conduction effect.
Design and characterization of a gas actuated pump for µTAS
Xiuhan Li, Xiaomei Yu
We present the results on the design, simulation, fabrication, and characterization of a gas-actuated micro-jet pump for integrated micro-fluidic systems. Vacuum suction mode provided by the pump can effectively decrease the formation of air bubbles and overcome the interface tension between the liquid and the solid wall in the micro-fluidic systems. Structurally the pump, which can be fabricated with only one etching step, consists of a nozzle, a diffuser, two suction tubes, a throat pipe, and a suction chamber. To optimize the parameters for the future designs, various pump configurations with different geometries were simulated through FLUENT software firstly. Then, the characteristics of the gas-actuated micro-jet pumps were studied experimentally. The pump began to work at a pressure of 2kPa, and the actuation pressure could be easily realized through a medical syringe.