This paper reports the design and experimental analysis of dielectrophoretic traps composed of four microfabricated gold electrodes excited in a quadrupolar fashion surrounding the electrodes with novel geometries for object detection. Implemented with a simple single-layer metal process, our microchip device makes the quadrupolar collection electrodes and detecting electrodes coplanar. Our scheme could not only make the collection system and the detection system in a chip integrated more easily, but provide possibility to synchronize the two systems and shorten response time. It is found that, at the low medium conductivities used, the existence of annular or parallel track detecting electrodes can hardly influence the separation efficiency, which shows that it is possible to drive targets to the object region rapidly by dielectrophoretic force while all the electrodes within a whole chip are coplanar. Dielectrophoresis effects of colloidal polystyrene particle are enhanced increasing the frequency of stimulating electric field.

To overcome shortcoming of traditional optical device, a photo system based on scanning electron microscope has been developed. The photo system is composed of built-in compact piezoelectric stage and electron-beam controller. The stage is made up of piezoelectric driver and grating encoder system. It can operate in vacuum and non-magnetic environments. The electron-beam controller includes controlling model, deflection model, image acquisition model and position error feedback model. Scanning field can be calibrated before scanning. The photo system can scan the IC chip which is wider than one scanning field quickly by using this nano-positioning stage. The position error can be compensated by the position error feedback model, so the stitching precision between neighborhood images is improved. Legible IC image is obtained by using this system.

MEMS thermal transducer is a promising technological platform for uncooled IR imaging. We fabricated MEMS IR FPA based on bi-material micro-cantilever and structured an uncooled MEMS IR System. In addition we obtained IR images of room temperature objects by it. Considering simplicity, low cost and efficiency the FPA readout is performed using an optical readout scheme in this system. The problem is some 'holes' will appear in the infrared images when some pixels of the FPA can not be detected by the readout. This paper present an algorithm based on the space pixel point. The algorithm can judge the characteristics of these 'holes' by using the follow parameters Average gray, Discrete and Regional gradient. After finding the 'holes' we can inpaint these 'holds' by the method of Regional growth. We have applied it to image output successfully. We present this algorithm and our results in the paper.

A novel resonant pressure sensor structure is proposed to achieve better performance in quality factor (Q) and output stability. Diffused silicon (15um) is used for the resonator, thus the resonator and the pressure diaphragm can be fabricated on the same silicon substrate without bonding. A differential detection tri-resonator structure is adopted to reduce the output drift and increase the sensitivity. To optimize the structure, a simplified 2-D model is set up for the theoretical analysis. In addition, 3-D models of the 'H' style beam and the entire structure which is composed of a diaphragm and three groups of beam respectively doubly supported by the anchors are constructed for the ansys-FEA simulation. Through the theoretical analysis and the simulation, the structure parameters (beam length, beam thickness, diaphragm thickness etc) are optimized. The natural frequency of the optimized model is 86.7 KHz, and the sensitivity is 19 KHz per 0.1MPa. The sensor is fabricated with the optimized parameters. The test experiments show that the results basically correspond with the simulation results except the effect of the wet etching in the fabrication process. The quality factor is 10000 in low vacuum, and the resolution is 1/10000.

The researches of single cell's control and operation are the hotspots in whole world. Among the various technologies, the transmission of ectogenic genetic materials between cell membrane is very significant. Imitating the Chinese traditional acupuncture therapy, a new ultrasonic resonance driving method, is imported to drive a cell's penetration probe. A set of the single cell penetration system was established to perform this function. This system includes four subsystems: driving part, micromanipulation part, observation and measurement part, and actuation part. Some fish egg experiments indicate that this system is workable and effective.

A micro potentiometric hemoglobin-A1c (HbA1c) immunosensor based on field-effect transistor (FET) and electrochemical growth of gold nanoparticles (AuNPs) in polypyrrole (PPy) film is reported. Integrated ion-sensitive field-effect transistors (ISFETs) chips containing two ISFETs, two reference FETs (REFET) and the signal read-out circuits were fabricated. Micro electrodes of the sensor were fabricated by MEMS techniques and electrochemical method, both compatible with electrode miniaturization. The simple and direct procedure to form PPy-AuNPs composite film enhances the sensitivity of the micro sensor. Electrochemical characterization and morphology study by scanning electron microscopy (SEM) confirm the presence of AuNPs in PPy. Simple, rapid and precise differential measurement of HbA1c is achieved. HbA1c in the concentration ranges of 2-20 ng/ml and 4-15 µg/ml can be detected by this sensor with a response time less than 1 min, which meets the needs of clinical detection of HbA1c. The miniaturized electrodes and integrated ISFET chip have the potential to be integrated and to achieve system on chip (SOC).

In this paper, a micro amperometric immunosensor based on Micro-Electro-Mechanical Systems technology for the detection of Salmonella typhimurium (S. typhimurium) was constructed by immobilizing a polyclonal antibody (the bio-molecular recognition element) onto the surface of polypyrrole(PPy) /staphylococcal protein A(SPA) modified Pt electrode. Pyrrole doped with SPA was co-electropolymerized onto the working electrode surface by cyclic voltammetry in 10 minutes for orientation-controlled immobilization of salmonella capture antibodies. S. typhimurium with the concentration of 10²cfu/ml could be detected by this immunosensor with a controllable and convenient manipulation to effectively modify the sensing surface more rapidly with less consumption of reagent (10µL), which showed the good property of the sensor. It is potential to develop a micro biosensor that can be used for convenient, accurate, cost-effective and real-time sensing of pathogens in food products.

To improve the performance of the micro-machined resonant pressure sensor and simplify its fabrication process, a novel structure is proposed in which the boron diffused silicon (up to 15um thickness) and the bulk silicon are used as the resonant beam and pressure membrane respectively. The structural parameters were optimized through FEM to achieve the better sensitivity, and the relationships between the structural parameters and the sensitivity were established. Moreover, the fabrication processes were discussed to increase the product rate and the pressure sensor with the optimal structural parameters was fabricated by the bulk silicon MEMS processes. In order to enhance the signal of the sensor and make the closed-looped control of the sensor easily, electromagnetic excitation and detection was applied. However there is so high noise coming from the distributing capacitances between the diffused silicon layer and electrodes that reduce the signal to noise ratio of the sensor. Through the analysis of the micro-structure of the sensor, the asymmetrical excitation circuit was used to reduce the noise and then the detection circuit was designed for this sensor. The resonator of the sensor was packaged in the low vacuum condition so that the high quality factor (Q) with about 10000 can be achieved. Experimental tests were carried out for the sensor over the range of -80kPa to 100kPa, the results show that the sensitivity of the sensor is about 20kHz/100kPa, the sensitivity is 0.01%F.S. and the nonlinearity is about 1.8%.

A novel structure of micro-machined vibrating ring gyroscope (MVRG) with electromagnetic excitation and detection is proposed, which consists of a ring and eight pairs of symmetric crab-leg suspension springs. The whole structure is mirror-symmetric and centrosymmetric, providing the possibility to realize good mode-matching when the temperature changes or acceleration shocks. The sensitivity of the MVRG is analyzed in detail, and the stability of the structure over temperature and acceleration loads is analyzed using finite element analysis. The prototype of vibrating ring gyroscope is successfully fabricated through bulk silicon processes which adopt only one silicon wafer without bonding process. The gyroscope chip is assembled with SmCo permanent magnet and packaged in a metal case. The design of self-oscillation closed-loop circuit is presented. FEA simulations show that the performance of the MVRG is stable over temperature and acceleration loads and the structure can withstand shock loads up to 10000g without any special protection. Test results show that the sensitivity of the MVRG is 8.9mv/°/s and the resolution is 0.05°/s with nonlinearity about 0.23% over a range of ±200°/sec.

Dielectrophoresis (DEP) is a promising method for the automated separation of biological cells in a miniaturized format. This technology allows cells to be manipulated electronically while suspended in a microfluidic channel embedded in a silicon lab-on-chip. Different dielectrophoretic configurations have been designed and fabricated using micro-electro-mechanical- systems (MEMS) technology, which are investigated comparatively on their function principles and separation efficiencies. DEP responses of colloidal polystyrene particles with the diameters of 10.9µm and 21.3µm suspended in deionized water are measured. It is found that, at the low medium conductivities used, global or local extreme points of electric fields can be configurated dependent on shapes and geometry sizes of electrodes. In addition, all the new phenomena appeared during whole experiment are observed, which may provide novel methods to separate micro particles.

Wire bonding is a solid phase welding process, where the two metallic materials (wire and pad surface) are brought into intimate contact. In order to ensure the accuracy and speed of bonding, micro-scoped pattern recognition systems (PRS) are often used to measure the deviation of the actual chip relative to the sampling position (eye-point). In this paper, a new mixed moment feature based matching algorithm is proposed for wire bonding. The important components of Zernike moments and wavelet moments are extracted to compose the mixed moment vector. The realization of location is by calculating the Euclidean distance of mixed moment vectors between the eye-point images and images to be matched. Experimental results show the rotation, translation invariance of the mixed moment features. The algorithm can improve the positioning accuracy while no increase in computational complexity, and can be well used in the precise positioning of the vision system for wire bonding.

In order to improve control precision of the piezoelectric ceramics (PZT) micro-displacement system, a self-adaptive fuzzy Proportional Integration Differential (PID) controller is designed based on the traditional digital PID controller combining with fuzzy control. The arithmetic gives a fuzzy control rule table with the fuzzy control rule and fuzzy reasoning, through this table, the PID parameters can be adjusted online in real time control. Furthermore, the automatic selective control is achieved according to the change of the error. The controller combines the good dynamic capability of the fuzzy control and the high stable precision of the PID control, adopts the method of using fuzzy control and PID control in different segments of time. In the initial and middle stage of the transition process of system, that is, when the error is larger than the value, fuzzy control is used to adjust control variable. It makes full use of the fast response of the fuzzy control. And when the error is smaller than the value, the system is about to be in the steady state, PID control is adopted to eliminate static error. The problems of PZT existing in the field of precise positioning are overcome. The results of the experiments prove that the project is correct and practicable.

Piezoelectric micro nebulizer is a typical piezoelectric-solid-liquid coupling problem. A 2D FEM model was presented for this system. Numerical results show that when the piezoelectric actuator is vibrated, nozzle film also is generated vibration, and the phase relationship occurs to them, and the operation at the second resonance frequency is more desirable than others. A good agreement between experimental results and theoretical results confirmed the validity of the theoretical model we developed. Therefore, the design of micro nebulizer to consider only the amplitude of piezoelectric vibration is not comprehensive, we must also consider the nozzle film vibration, as well as the phase between the back film and the nozzle film, and this can provide guidance for the optimal design of micro nebulizer.

This paper takes the cantilever beam MEMS switch as an example to discuss mechanical principle and function simulation of the RF MEMS switch used in radio frequency communication. We select three kind s of the cantilever beams with different sections to analyze their switch characteristics, and with the help of finite element analysis(FEA) software ANSYS, multi-physical coupling analysis and simulation are carried out. The threshold voltage, the inherent frequency of these beams, optimal design, random vibration analysis and fatigue lifetime analysis are also discussed in detail. The results provide a good theoretical help to design various high performance RF MEMS switches with variational section beam.

Grating Light Modulator(GLM) based on MEMS is applied in projection display. In order to eliminate crosstalk of GLM array, a monolithic integration device of GLM and active matrix is presented with post-CMOS process. The operating principle of monolithic integration device is introduced. Active matrix unit is composed of a NMOS transistor and a capacitor. The bottom electrode of GLM is connected to the electrode of the capacitor by via, so the voltage of GLM equals to the voltage of capacitor. Every GLM unit is controlled by sole active matrix unit, so crosstalk can be eliminated, which improves optical contrast and optical utilization ratio. And, the monolithic integration process of active matrix and GLM is designed. Then the key indexes and parameters of active matrix which influences the performance of monolithic integration device are analyzed in detail. It's indicated by analysis that storage capacitor and width-length ratio of transistor influence the holding-voltage property and switch speed of monolithic integration device. Finally, with 0.18µm process design kit(PDK) of SMIC and Cadence software, layout of monolithic integration device is designed. The simulation results validate the correctness of the analyzed theory and the designed circuits. The monolithic integration device designed can be applied in projection display which has 1920×1080 resolution, 30Hz frame frequency and 256 grayscales.

UV curing nanoimprint is demonstrated for high aspect ratio gratings fabrication based on SU-8 for nanophotonics and biochemical applications. The defects, which are caused by stress and friction between mold and resist and air bubbles are key issues. To eliminate the defects, the process parameters, such as imprinting pressure, baking time and demolding temperature, are optimized. SU-8 grating with 150nm in width and 1.5µm is presented with good uniformity in large area using Si template fabricated by non-switching DRIE process. The process could find broader applications in the manufacture of biochemical devices and nanophotonic structures.

MEMS have become viable systems to utilize for uncooled infrared imaging in recent years. They offer advantages due to their simplicity, low cost and scalability to high-resolution FPAs without prohibitive increase in cost. 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, processed by a sparse representation-based image denoising and inpainting algorithm, which generalizing the K-Means clustering process, for adapting dictionaries in order to achieve sparse signal representations. 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.

Direct thermal bonding approaches are especially desirable as they allow formation of enclosed microchannels with uniform surfaces composed entirely of the same polymeric material. It is often believed that the main phenomenon involved during thermal bonding is a chain entanglement of the polymers over the boundary. If the temperature is too high and/or the application of the force is too long then the polymer will flow and refill the channels caused by capillary forces, called as roof filling phenomenon. In order to understand this process more fully, we describe an experimental method for characterizing the roof filling rate inside a microchannel by measuring the polymer marching velocity or position of a capillary meniscus during thermal bonding. 1D nanochannels was fabricated succesfully and the vertical dimension was well controlled according to the top filling mechnism.

This paper proposes a novel Hadamard Transform near-infrared spectrometer based on MOEMS(Optical micro-electro-mechanical system ) grating light modulator. A new method that grating light modulator combined with a single near -infrared detector to detect spectrum is applied. The programmability of the grating light modulator linear array is used to implement a Hadamard Transform encoding masks. Firstly, optics theory has been used to analyze the essential principle of the spectrometer and the optical principle of grating light modulator. Then, It is theoretically proved that the Hadamard Transform near-infrared spectrometer can reconstruct spectrum effectively and have a high signal noise ratio. Finally, a new structure of the grating light modulator is given. Results of the software simulation show that 5.5V maximum actuating voltage and 5 kHz response frequency are suitable for a miniature, portable, cost-efficient spectrometer.

A novel subwavelength dual-layer metallic nanowire-grid polarizer is designed for visible region. The difference between the designed and the available nanowire-grid polarizer is that the former adds a high refractive index dielectric layer between the substrate and the dielectric grating. It is found that the high refractive index dielectric layer can improve the performance of polarizer. Effects of the thickness of the high refractive index dielectric layer, the incident angle and the duty cycle on the TM polarization transmission efficiency as well as the extinction ratios are analyzed using rigorous couple-wave theory. Based on the simulation results, a polarizer with high TM transmission efficiency and high extinction ratios over a wide incident angle is designed. It gives TM transmission efficiency over 79% and extinction ratios higher than 56.6dB until the incident angle is θ= 60°

A clamped-clamped beam (CC beam) in-plane capacitive resonator with 100nm gap has been analyzed and fabricated by silicon micromachining technique in this paper. The nonlinearity effects in this device and the resonant mode of the main structure are analyzed and the overall system dynamics of motion equation and general solution are given firstly. The simulation results of resonant mode indicate that the structure size of the beam has great influence on the resonant frequency of beam. Moreover, with the high aspect-ratio combined poly- and single-crystal silicon micromachining technology (HARPSS), 100nm gap in-plane capacitive resonator has been fabricated.

In recent years, many kinds of 1-dimension nano-materials (Carbon nanotube, ZnO nanobelt and nanowire etc.) continue to emerge which exhibit distinct and unique electromechanical, piezoelectric, photoelectrical properties. In this paper, a 1-dimension nano-materials-based device was proposed. The bottom-up and top-down combined process were used for constructing CNT-array-based device and ZnO nanowire device. The electrical characteristics of the 1D nano-materials-based devices were also investigated. The measurement results of electrical characteristics demonstrate that it is ohm electrical contact behavior between the nano-material and micro-electrodes in the proposed device which also have the field effect. The proposed 1D nano-material-based device shows the application potential in the sensing fields.

This paper primarily involves in coupled vibrating between the micro airflow and its electrostatic actuator in a MEMS sealed chamber structure. Both the air damping effect and the Rayleigh-ritz energy method have been utilized to investigate the coupled effect between the micro airflow and its actuator. The air pressure distribution of the micro airflow has been determined by solving the linerized isothermal compressible Reynolds' equation and combined with the sealed pressure boundary condition. The coupled model of electrostatic-Silicon membrane-micro airflow has been established according to the Rayleigh-Ritz energy method. From the coupled model, the undetermined coefficient of the displacement function of such coupled vibrating can be derived. By comparing the undetermined coefficient λ' of the displacement function without micro airflow and the undetermined coefficient λ' of the displacement function with micro airflow, the air damping factor has been extracted. The influencing of micro airflow on electrostatic actuator can be exhibited by such air damping factor. And dynamic performance of this kind of MEMS fluidic devices can be improved by regulating and controlling the air damping factor. All the investigation provide theoretical foundation and control strategy for micro fluid actuating.

The field of micro electromechanical systems (MEMS), particularly micro sensors and transducers, has been expanding over recent years, and the production of these devices continue to grow up. With SU-8 photoresist, the technology of UV-LIGA has been developed as an important method of fabrication micro structures. The process consisting of photolithographic and microelectroforming were studied in this paper. Orthogonal experimental design were applied in research. From experiment it can be concluded that the soft bake temperature and time was the key factor of the structure quality. When the photoresist thickness ranged from 120 to 340µm, the soft bake temperature and time was 90 and 50~120 minutes, that means the perfect image. The best post expose bake temperature was 85 95 with less 40 minutes bake. In order to obtain the suitable parameters of the various thickness photoresist, an artificial neural network (ANN) with 3 layers were built. The ANN were trained based on orthogoality experiment using back propagation algorithm. Compared to the experiment results, the prediction error was less than 2.0%, which proved that the ANN was effective. The characteristics of the microelectroforming process were analysed systematically. The results showed that the mass transfer is the control factors of microelectroforming process. During the developing of the photoresist, ultrasonic stirring could shorten the developing time and improve the micro mould quality effectively.The lithographic and microelectroforming process of the fabrication of high resolute micro structure was optimized.