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micrograting Displacement Sensor with Integrated Electrostatic Actuation

Chinese Physics Letters 2014年第7期31卷 214-217页

作者：姚保寅冯丽爽王潇刘惟芳刘美华 Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education) Beihang University Beijing 100191 Fundamental of Science on Novel Inertial Instrument & Navigation System Technology Laboratory Beihang University Beijing 100191

A high-resolution micro-grating displacement sensor with diffraction-based and integrated electrostatic actuation is proposed and experimentally demonstrated. The Ai reflecting membrane is fabricated at the bottom of a silicon moving part and the Au micro-gratings are patterned on a transparent substrate. This structure forms a phase sensitive diffraction grating, providing the displacement sensitivity of the micro-grating interferometer. It shows sensitivity adjustment and self-calibration capabilities with electrostatic actuation. Additional system components include a coherent light source, photodiodes, and required electronics. Experimental results show that the displacement sensor has a sensitivity of about 1.8 m V /nm and a resolution of less than 1 nm in the linear region. This displacement sensor is very promising in the fields requiring high sensitivity, broad dynamic range, and immunity to electromagnetic interference.

关键词： ELECTROSTATIC actuators DISPLACEMENT (Mechanics) DIFFRACTION gratings SENSITIVITY analysis SILICON

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Morphology and Crystallinity-controlled Synthesis of Manganese Cobalt Oxide/Manganese Dioxides Hierarchical nanostructures for High-Performance Supercapacitors

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功能材料信息 2015年第4期12卷 17-32页

作者： Fei Li Gang Li Hao Chen Jia Qi Jia Fan Dong Yao Bo Hu Zheng Guo Shang 张育新 College of Materials Science and Engineering Chongqing University State Key Laboratory of Porous Metal Materials Northwest Institute for Nonferrous Metal Research Chongqing Key Laboratory of Catalysis and Functional Organic Molecules College of Environmental and Biological Engineering Chongqing Technology and Business University National Key Laboratory of Fundamental Science of Micro Nano-Devices and System TechnologyChongqing University 重庆大学材料学院

We demonstrate a novel preparative strategy for the well-controlled MnCo_2O_(4.5)@MnO_2 hierarchical ***δ-MnO_2 nanosheets andα-MnO_2 nanorods can uniformly decorate the surface of MnCo_2O_(4.5)nanowires to form core-shell *** electrochemical characterization reveals that MnCo_2O_(4.5)@δ-MnO_2 pattern exhibits not only high specific capacitance of 357.5 F g^(-1)at a scan rate of 0.5 A g^(-1),but also good cycle stability(97%capacitance retention after 1000 cycles at a scan rate of 5 A g^(-1)),which make it have a promising application as a supercapacitor electrode material.

关键词： MnO2 Manganese cobalt oxide Chemical synthesis Core-shell nanostructures Supercapacitor

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Sensitivity analysis of light force accelerometer based on optical trapping Mie microsphere

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Optoelectronics Letters 2014年第1期10卷 77-80页

作者：冯丽爽焦洪臣姚保寅 Key Laboratory of Micro-nano Measurement-Manipulation and Physics Ministry of EducationFundamental Science on Novel Inertial Instrument & Navigation System Technology LaboratoryBeijing University of Aeronautics and Astronautics

For achieving the greatest sensitivity,numerical simulation is proposed to optimize the parameters of light force accelerometer(LFA).Firstly,the basic principle of the LFA is analyzed,and the mathematical model is established to describe the axial and radial optical trapping forces on microspheres in the fundamental mode Gaussian laser ***,the axial and radial optical trapping forces applied on Mie spheres are simulated to obtain the optimal parameters of open-loop *** show that the sensitivity can reach 103μm/***,the LFA system is proposed based on the closed-loop scheme with dual *** can provide reference for the design and fabrication of LFA in future.

关键词：敏感度分析加速度计捕获光学数值模拟高斯激光束数学模型最优参数

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fundamentals of phase-only liquid crystal on silicon (LCOS) devices

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Light(science & Applications) 2014年第1期3卷 43-52页

作者： Zichen Zhang Zheng You Daping Chu State Key Laboratory of Precision Measurement Technology and Instruments Collaborative Innovation Center for Micro/Nano FabricationDevice and SystemDepartment of Precision InstrumentTsinghua UniversityBeijing 100084China Electrical Engineering Division Department of EngineeringUniversity of CambridgeCambridge CB30FAUK

This paper describes the fundamentals of phase-only liquid crystal on silicon(LCOS)technology,which have not been previously discussed in *** technology is widely utilized in high efficiency applications for real-time holography and diffractive *** paper begins with a brief introduction on the developmental trajectory of phase-only LCOS technology,followed by the correct selection of liquid crystal(LC)materials and corresponding electro-optic effects in such *** is focused on the essential requirements of the physical aspects of the LC layer as well as the indispensable parameters for the response time of the ***,the basic functionalities embedded in the complementary metal oxide semiconductor(CMOS)silicon backplane for phase-only LCOS devices are illustrated,including two typical addressing ***,the application of phase-only LCOS devices in real-time holography will be introduced in association with the use of cutting-edge computer-generated holograms.

关键词： electro-optic effect liquid crystal material liquid crystal on silicon device real-time holography

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A new hybrid piezoelectric-electromagnetic micro vibration energy harvester

A new hybrid piezoelectric-electromagnetic micro vibration e...

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IEEE Conference on Electron devices and Solid-State Circuits

作者： Hua Yu Jielin Zhou Wei Wang College of Optoelectronic Engineering Chongqing China Key Laboratory for Optoelectronic Technology & Systems Ministry of Education of China Chongqing China National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology Chongqing China

ISBN: (纸本)9781479923366

The paper presents a new hybrid micro piezoelectric-electromagnetic generator for vibration energy harvesting, which generates energy from low frequency and small amplitude vibration environment, using piezoelectric and electromagnetic conversion mechanisms. The paper outlines factors needed when designing the hybrid energy harvester, including the coupling mathematical model, the finite element analysis, optimization procedure and trade-offs. The proposed hybrid energy harvester is also fabricated and experimental results show that the device can generate an open-circuit voltage of 4.32V and produce a power of 13.47μW with an optimal resistive load of 403KΩ at 0.1 m/s 2 acceleration and 105.2 Hz frequency.

关键词： Materials Electromagnetics Arrays Resistance Coils

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Design of power management chip for piezoelectric energy harvesting

Design of power management chip for piezoelectric energy har...

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IEEE Conference on Electron devices and Solid-State Circuits

作者： Hua Yu Shibo Yang Wei Wang College of Optoelectronic Engineering Chongqing University Chongqing China Ministry of Education of China The Key Laboratory for Optoelectronic Technology & Systems Chongqing China National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology Chongqing China

ISBN: (纸本)9781479923366

The paper proposes a complete energy harvesting solution integrated with a low-loss AC/DC rectifier and a high efficiency low dropout regulator (LDO) optimized for micro piezoelectric energy harvester. The AC/DC module converts AC into DC and then supplies power for the following LDO circuit module, through which the whole chip can obtain a stable 3.3V output voltage. A dynamic compensation mechanism is presented to improve the loop stability of LDO, which is easier to achieve high phase margin than traditional compensation strategy. The simulation results of LDO indicate that the typical dropout is 0.4mV with 1mA load current and 61mV with 150mA load current respectively, and the typical voltage line regulation error is 0.025%/V. In addition, the typical load regulation error was 0.00018%. The results demonstrate that the proposed chip meets the requirements of power supply for wireless sensor node (WSN).

关键词： Photonic band gap

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Calculation of surface acoustic waves in a multilayered piezoelectric structure

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Journal of Semiconductors 2013年第1期34卷 6-11页

作者：张祖伟温志渝胡晶 Key Laboratory of Fundamental Science on Micro/Nano-Device and System Technology Chongqing University National Center for International Research of Micro/Nano-System and New Material Technology Chongqing University Microsystem Research Center Chongqing University

The propagation properties of the surface acoustic waves（SAWs） in a ZnO-SiO2-Si multilayered piezoelectric structure are calculated by using the recursive asymptotic *** phase velocities and the electromechanical coupling coefficients for the Rayleigh wave and the Love wave in the different ZnO-SiO2-Si structures are calculated and *** Love mode wave is found to be predominantly generated since the c-axis of the ZnO film is generally perpendicular to the *** order to prove the calculated results,a Love mode SAW device based on the ZnO-SiO2-Si multilayered structure is fabricated by micromachining,and its frequency responses are *** experimental results are found to be mainly consistent with the calculated ones,except for the slightly larger velocities induced by the residual stresses produced in the fabrication process of the *** deviation of the experimental results from the calculated ones is reduced by thermal annealing.

关键词： SAW RAM multilayered structure

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Smearing model and restoration of star image under conditions of variable angular velocity and long exposure time

Smearing model and restoration of star image under condition...

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作者： Sun, Ting Xing, Fei You, Zheng Wang, Xiaochu Li, Bin Department of Precision Instrument Tsinghua University Beijing 100084 China State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua University Beijing 100084 China Collaborative Innovation Center for Micro/Nano Fabrication Device and System Tsinghua University Beijing 100084 China

The star tracker is one of the most promising attitude measurement devices widely used in spacecraft for its high accuracy. High dynamic performance is becoming its major restriction, and requires immediate focus and promotion. A star image restoration approach based on the motion degradation model of variable angular velocity is proposed in this paper. This method can overcome the problem of energy dispersion and signal to noise ratio (SNR) decrease resulting from the smearing of the star spot, thus preventing failed extraction and decreased star centroid accuracy. Simulations and laboratory experiments are conducted to verify the proposed methods. The restoration results demonstrate that the described method can recover the star spot from a long motion trail to the shape of Gaussian distribution under the conditions of variable angular velocity and long exposure time. The energy of the star spot can be concentrated to ensure high SNR and high position accuracy. These features are crucial to the subsequent star extraction and the whole performance of the star tracker. © 2014 Optical Society of America.

关键词： Image reconstruction

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The fabrication of vibration energy harvester arrays based on AlN piezoelectric film

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Journal of Semiconductors 2013年第11期34卷 79-82页

作者：尚正国李东玲温志渝赵兴强 Key Laboratory of Fundamental Science on Micro/Nano-Device and System Technology Chongqing University National Center for International Research of Micro/Nano-System and New Material Technology Chongqing University Microsystem Research Center of Chongqing University

： The fabrication and measurement results of the vibration energy harvester arrays based on the piezoelectric aluminum nitride （AlN） film are presented. The structure design and fabrication process of the device are introduced. The key material, the AIN film with crystal orientation （002）, was deposited by pulsed-DC magnetron sputtering and characterized by X-ray diffraction （XRD）. The resonant frequency, power out, and the open circuit voltage of the device are detected. The optimized load of 80 kΩ and a remarkable maximum power out of 30.4 μW are obtained when the acceleration of 0.9g （g is standard gravity acceleration） is applied. key words： A1N; crystal orientation; harvester arrays; vibration energy

关键词： AlN crystal orientation harvester arrays vibration energy

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Low temperature Si/Si wafer direct bonding using a plasma activated method

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Journal of Zhejiang University-science C(Computers and Electronics) 2013年第4期14卷 244-251页

作者： Dong-ling LI Zheng-guo SHANG Sheng-qiang WANG Zhi-yu WEN National Key Laboratory of Fundamental Science of Novel Micro/Nano Device and System Technology Chongqing University MOE Key Laboratory of Optoelectronic Technology & Systems Chongqing University Microsystem Research Center Chongqing University

Manufacturing and integration of micro-electro-mechanical systems （MEMS） devices and integrated circuits （ICs） by wafer bonding often generate problems caused by thermal properties of materials. This paper presents a low temperature wafer direct bonding process assisted by 02 plasma. Silicon wafers were treated with wet chemical cleaning and subsequently activated by 02 plasma in the etch element of a sputtering system. Then, two wafers were brought into contact in the bonder followed by annealing in N2 atmosphere for several hours. An infrared imaging system was used to detect bonding defects and a razor blade test was carried out to determine surface energy. The bonding yield reaches 90%--95% and the achieved surface energy is 1.76 J/m2 when the bonded wafers are annealed at 350 ~C in N2 atmosphere for 2 h. Void formation was systematically observed and eli-mination methods were proposed. The size and density of voids greatly depend on the annealing temperature. Short O2 plasma treatment for 60 s can alleviate void formation and enhance surface energy. A pulling test reveals that the bonding strength is more than 11.0 MPa. This low temperature wafer direct bonding process provides an efficient and reliable method for 3D integration, system on chip, and MEMS packaging.

关键词： Low temperature Wafer direct bonding O2 plasma activation Surface energy Void formation

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