Browsing by Author "Chiou, JC"

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A back-to-back micromirror device for optical add/drop multiplexer applications
(2003)
Lin, YC
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Chiou, JC
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電控工程研究所
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Institute of Electrical and Control Engineering
In this paper, a back-to-back micromirror device fabricated through surface-micromachining and flip chip packaging technologies is developed for optical add/drop multiplexer applications. Pre-stressed beams were designed to elevate micromirror devices after the release and thermal heat-treatment processes. Torsion flexure structure design provides a reliable rotation degree of freedom for micromirror devices. A mechanical stopper was bonded using flip chip packaging on the top of micromirror devices to constrain the popped-up micromirror to obtain precise deflecting angle. Preliminary experiments had demonstrated the feasibility of the micromirror devices.
A CVD epitaxial deposition in a vertical barrel reactor: Process modeling using cluster-based fuzzy logic models
(1998-11-01)
Chiou, JC
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Yang, JY
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電控工程研究所
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Institute of Electrical and Control Engineering
A chemical vapor deposition (CVD) epitaxial deposition process modeling using fuzzy logic models (FLM's) has been proposed. The process modeling algorithm consists of a cluster estimation method and backpropagation algorithm to construct a number of modeling structures from the training data. A decision rule based on the multiple correlation factor is used to obtain the optimum structure of fuzzy model using the testing data. Upon the optimum structure has been reached, the gradient-descent method is used to refer the parameters of the final fuzzy model using both training and testing data. The algorithm has been applied to a nonlinear function and a vertical chemical vapor deposition process, The results demonstrate the efficiency and effectiveness of the proposed fuzzy logic model in comparison with existing fuzzy logic models and artificial neural network models.
A micromirror device with tilt and piston motions
(1999)
Chiou, JC
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Lin, YC
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電控工程研究所
;
Institute of Electrical and Control Engineering
A newly developed micromirror device that possesses two rotational (tilt) and one displacement (piston) degrees of freedom has been designed and fabricated by using surface micromachining technology. The device consists of a micromirror, four vertical thermal-actuator arrays and four torsion bars that connect the mirror and the actuator. The vertical thermal actuator has the capability to elevate from its origin position. To demonstrate the feasibility of the vertical thermal actuator, various layouts and sizes has been designed. The present device was fabricated through the Multi-User MEMS process (MUMPs). When the controlled signal is applied to any two adjacent thermal-actuator arrays of the device, the remain two thermal actuator arrays and torsion bars will act as the supporting beams that allow the micromirror to experience rolling or pitching motion. On the other hand, by applying controlled signals to all four thermal-actuator arrays synchronously, the micromirror would elevate vertically. Note that different rolling or pitching angle of the micromirror can be archived by designing the locations of the torsion bars with vertical thermal actuators. Through the process, a compact, extremely light in weight, potentially low cost, and operating in very low voltage (<10V) micromirror device with various applications can be obtained.
A novel capacitance control design of tunable capacitor using multiple electrostatic driving electrodes
(2001)
Chiou, JC
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Lin, YC
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電控工程研究所
;
Institute of Electrical and Control Engineering
A novel control design method that is capable of linearly electrostatic driving a tunable capacitor is proposed in this paper. By extending the derivation of electrostatic theory and elastic theory in constructing the tunable capacitor, the nonlinear relationship between applied voltages and displacement (air gap) between two parallel plates of the capacitor is obtained. To suppress the nonlinearity so that the gap between the capacitor can vary linearly with the applied voltage, a control design method based on the variation of the multi-rectangular electrodes and applied voltages is proposed. By varying the number of rectangular electrodes that are evenly divided according to the size of the upper plate of the capacitor, the working space of the tunable capacitor with nonlinear characteristics is obtained. With this working space, linear control design method based on fixed or linearly varied applied voltages can be used to determine the number of the multi-rectangular electrodes such that stepping effect of the tunable capacitor can be achieved. Examples are used to demonstrate the feasibility of the present control design. Simulation results indicated that the linear control design method matched closely with the analytical analysis.
A novel large displacement electrostatic actuator: pre-stress comb-drive actuator
(2005-09-01)
Chiou, JC
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Lin, YJ
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電控工程研究所
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Institute of Electrical and Control Engineering
This investigation proposes a novel large vertical displacement electrostatic actuator, called the pre-stress comb-drive actuator (PCA), which exhibits no pull-in and no hysteresis characteristics. The proposed PCA consists of a set of comb fingers fabricated along the composite beam and substrate. One end of the composite beam is clamped to the anchor, whereas the other end is elevated vertically by the residual stress. The actuation occurs when the electrostatic force, induced by the fringe effect, pulls the composite beam downward to the substrate. A post-heat treatment process was employed to increase the initial lift height of the PCA to obtain a large actuation stroke. A mathematical model, based on a newly developed modeling approach, is introduced to estimate the static characteristic of the PCA. A PCA was fabricated using the PolyMUMPs process based on the proposed design concept. Following packaging and applying a post-heat treatment process, a 110 mu m initial tip height and a 90 mu m vertical motion range were achieved. Neither pull-in nor hysteresis was observed. The simulation results were closely matched with the observations. This work also studies the frequency response and measurement of the maximum vibration of the PCA.
A photonic device compatible process in fabricating tunable Fabry-Perot filter
(2002-09-15)
Lin, WT
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Chiou, JC
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Chou, BCS
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電控工程研究所
;
Institute of Electrical and Control Engineering
A photonic device compatible low temperature process that is suitable for fabricating tunable Fabry-Perot filter is proposed in this paper [1]. The advantages of the presented process consist of (1) materials used in this process are compatible with existing optical or IC process; (2) process and detected spectra are not limited by different substrates. Experimental results of the manufactured tunable Fabry-Perot filter indicated that the full-width-half-maximum (FWHM) is closed to 1.3 nm and the measurement of reflectance of distributed Bragg reflectors is up to 99%. Note that within the 10 nm experimental tuning range, the FWHM is kept close to 1.3 nm with tuning voltage from 0 to 30 V. The experimental results showed that the presented process has potential to apply to wavelength division multiplexing (WDM) specifications of optical telecommunication. In particular, the process would also be integrated to fabricate tunable VCSEL processes. (C) 2002 Elsevier Science B.V. All rights reserved.
A self-aligned fabrication method of dual comb drive using multilayers SOI process for optical MEMS applications
(2005-02-01)
Lin, WT
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Chiou, JC
;
Tsou, C
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電控工程研究所
;
Institute of Electrical and Control Engineering
A novel method for fabricating a self-aligned electrostatic dual comb drive using a multi-layer SOI process is developed. The present method utilizes four aligned masks, greatly simplify the existing SOI-MEMS fabrication methods in manufacturing optical MEMS devices. Here, the actuating structure consists of fixed combs and moving combs that are composed of single crystal silicon, nitride and polysilicon. One mask is used to provide a deep etching to etch polysilicon, nitride and single crystal silicon respectively. The nitride separates polysilicon and single crystal silicon and provides an additional dielectric for the purpose of producing bi- directional motion upon applying electrostatic forces. A dual comb drive actuator with optical structures was fabricated with the developed process. The actuator is capable of motion 250 nm downward and 480 nm upward with 30 V applied voltage at 4 kHz frequency. The dynamic characteristics of the first and the second resonant frequency of the dual comb-drive actuator are 10.5 kHz and 23 kHz respectively. Experimental results indicated that the measured data agreed well with simulation results using the ANSOFT Maxwell((R)) 2D field simulator, ANSYS((R)) and Coventor Ware((R)).
A tilting micromirror with well-controlled digital angle through constrained lever structure
(2004)
Chiou, JC
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Kuo, CF
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Lin, YC
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電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, a tilting micromirror device that can achieve designed angle is proposed. A lever structure, driven by electrostatic actuators, was used to enlarge tilting angle. To obtain precise deflecting angle, the lever structure is constrained by the substrate. By applying a voltage, the electrostatic actuators drive the lever down to the substrate such that the micromirror device on the opposite side of the lever structure could be lifted. PolyMUMPs process was used to fabricate proposed micromirror devices. The actuators are simulated to investigate characteristics of the micromirror devices. Experimental results had indicated that the micromirror device could reach 10-degree tilting angle with 80V driving signal with 6.4% relative error compared to designed model.
Attitude control system for ROCSAT-3 microsatellite: a conceptual design
(2005-02-01)
Jan, YW
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Chiou, JC
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電控工程研究所
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Institute of Electrical and Control Engineering
The ROCSAT-3 attitude control subsystem is conceptually designed to meet the weight and power constraints of a microsatellite. Attractive features of the proposed design include (a) a control scheme for initial attitude acquisition, which provides a fully autonomous attitude hold, no duration limit and adequate attitude for power generation and (b) a feasible implementation for a microsatellite which has uncommon mission demands such as an orbit raising maneuver and practical weight and power constraints. The proposed control schemes for the three control modes and the spacecraft attitude dynamics are analyzed to demonstrate the satisfaction of the designated mission goals. (C) 2004 Elsevier Ltd. All rights reserved.
Closed-loop fuzzy control of torsional micromirror with multiple electrostatic electrodes
(2002)
Chiou, JC
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Lin, YC
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Wu, SD
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電控工程研究所
;
Institute of Electrical and Control Engineering
Constraint violation stabilization using input-output feedback linearization in multibody dynamic analysis
(1998-03-01)
Chiou, JC
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Wu, SD
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電控工程研究所
;
Institute of Electrical and Control Engineering
A constraint violation stabilization technique for solving differential algebraic equations (DAE) of multibody dynamic systems is presented. The technique, based on the input-output feedback linearization, is employed to transform the nonlinear DAE into a set of linear equations. Pin reaching the input-output linear relationship with proven stable zero dynamics, a robust control design is adopted to construct constraint forces that can be used to effectively correct the errors accumulated in the constraint equations during the process of time integration. In the present development. If the pole placement method is used in control design of the resulting linear differential equations, constraint forces based on Baumgarte's constraint violation stabilization technique are recovered. On the other hand, if variable structure control design is adopted, a new method in calculating constraint forces is obtained. Two numerical examples are used to demonstrate the effectiveness of stabilizing the constraint violation by using the proposed technique.
Dielectric degradation of Cu/SiO2/Si structure during thermal annealing
(1996-03-01)
Chiou, JC
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Wang, HI
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Chen, MC
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
The impact of Cu on the dielectric SiO2 layer was studied using a Cu/SiO2/Si metal oxide semiconductor capacitor and rapid thermal annealing (RTA) treatment. With the RTA treatment, no chemical reaction was observed up to 900 degrees C; however, dielectric degradation occurred following RTA at 300 degrees C for 60 s and became worse with the increase of annealing temperature. The interface-trap density at the SiO2/Si interface also increased from 5 x 10(10) to 5 x 10(13) eV(-1) cm(-2) after 800 degrees C RTA treatment. The RTA anneal introduced a large number of positive Cu ions into the dielectric SiO2 layer. Under bias-temperature stress, Cu ions drift quickly in the SiO2 layer and may drift across the SiO2/Si interface and enter the Si substrate. With the use of 1200 Angstrom thick TiN and TiW barrier layers, respectively, the dielectric strength of the Cu/(barrier)/SiO2/Si structures was able to remain stable up to 500 and 600 degrees C.
Dynamic characteristics measurement system for optical scanning micromirror
(2000)
Chiou, JC
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Lin, YC
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Chang, YC
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper describes the development of a novel, flexible, with appropriate accuracy dynamic characteristics measurement system for optical scanning micromirror. With the system, we can measure dynamic behaviors such as transient response, scan speed, scan angle, scan repeatability, and scan non-linearity of the scanning micromirror devices. Moreover, the optical system performances such as scan spot size and even scan spot intensity can also be obtained.
Family of constraint-preserving integrators for solving quaternion equations
(2001-01-01)
Chiou, JC
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Jan, YR
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Wu, SD
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電控工程研究所
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Institute of Electrical and Control Engineering
A family of numerical time integrators that exactly preserve the constraint of quaternion equations is developed, The constraint-preserving integrators based on the property of the skew-symmetric matrix and the proposed proven theorems are used to improve the accuracy of updating Euler parameters. The stability and accuracy analysis of the generalized constraint-preserving integrators is also discussed. Furthermore, we demonstrate that the proposed integrators are A-stable integrators that are proven to be useful in calculating angular orientations of kinematic and dynamic systems. A numerical example is used to demonstrate the superiority of the proposed integrators.
Fuzzy macromodel for dynamic simulation of microelectromechanical systems
(2006-07-01)
Ko, CH
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Chiou, JC
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper proposes an efficient approach that consists of an experimental design and a fuzzy-logic model (FLM) to generate macromodels for the simulation of microelectromechanical systems. Firstly, in the present approach, a force macromodel is adapted to perform the coupled simulations. Then, an experimental design is utilized to reduce the number of data needed for macromodel identification, and an FLM is chosen to fit the data. The identification scheme involves cluster estimation to determine the FLM structure and backpropagation method to efficiently obtain the FLM structure parameters that lead to an accurate macromodel. In order to verify the accuracy of the macromodel, the approach has been applied to a magnetic microactuator. The simulation results show that the force macromodel yielded errors of less than 1.5% for a 5-mu m displacement. Furthermore, the dynamic coupled simulation takes only several minutes. The results demonstrate the efficiency and effectiveness of the current approach.
Magnetic analysis of a micromachined magnetic actuator using the finite element method
(1999)
Ko, CH
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Yang, JJ
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Chiou, JC
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Chen, SC
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Kao, TH
In this paper, a parametrical method is developed to design a magnetic microactuator. The method is based on modeling the magnetic microactuator using the finite element analysis software that can be used to calculate the energy density and magnetic force. Here, the concept of design on experiments (DOE) is used to identify critical parameters that affect the performances of the electromagnetic microactuator. Numerical simulation results from a series of DOE have indicated that the dimension of core and the magnetic material block have the influence on planar electromagnetic actuators. When the length of the magnetic components is equal to that of outer diameter of coil circuit, we obtain the best efficiency in magnetic force. Furthermore, when we increase the thickness of the magnetic materials block or shorten the distance between the coils and magnetic material block, the magnetic force will increase dramatically. In addition, we can achieve a great magnetic force when the combination ratio of the length of the core is half of the magnetic material block. Simulation results have shown that electromagnetic actuators with high aspect ratio planar coil could sustain higher electrical current that consequently increases the magnetic force. During the realistic fabrication, the thick resist patterning and electroplating technologies is used to fabricate:the above-mentioned electromagnetic microactuator. Experimental results indicated that the magnetic force follows closely to the simulation results.
MEMS-based miniature optical pickup
(2005-02-01)
Chiu, Y
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Chen, CH
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Chiou, JC
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Fang, WL
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Shieh, HPD
The technology challenges for miniature optical pickups include high-numerical-aperture objective lens design, servo actuator functions and performance, and component assembly tolerance. In this paper, a microelectromechanical systems (MEMS)-based miniature optical pickup is proposed for DVD and blue disk systems. A high-order diffractive objective lens with a continuous surface relief is designed. Focus, tilt, and tracking servos are implanted with MEMS micro actuators. Preliminary design and test results are presented.
Minimum-time spacecraft maneuver using sliding-mode control
(2004-01-01)
Jan, YW
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Chiou, JC
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電控工程研究所
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Institute of Electrical and Control Engineering
The purpose of this paper is to present a sliding mode control method that can be used to perform a spacecraft large angle maneuver with minimum time. An algorithm of minimum-time SMC is developed to provide the robust tracking control. The simulation results are compared with previous developed control schemes, eigenaxis quaternion regulator, to demonstrate the superiority of the proposed sliding mode control algorithm. (C) 2003 Elsevier Ltd. All rights reserved.
Modeling and verification of the double frequency effect using a MEMS device
(2006-07-01)
Chiou, JC
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Lin, YJ
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電控工程研究所
;
Institute of Electrical and Control Engineering
The derivation, verification, and implication of the nonlinear dynamic and frequency response of electrostatic actuator due to the double frequency effect (DFE) were reported in this study. In particular, an extra mode called half mode was observed and measured in various studies. However, a complete in-depth discussion of the effect was not reported in the past. In the present study, a second-order dynamical equation was adapted firstly to model the dynamic and frequency response of electrostatic actuator where typical harmonic input signal with a dc bias was used. Secondly, by solving the equation, complex waveform in dynamic response and an extra half mode in frequency response due to the double frequency effect can be observed and discussed. To verify the simulated result, an electrostatic driving device was fabricated using PolyMUMPS(C) process. Note that in frequency response, when dc bias is equal to the amplitude of ac signal, simulated and experimental results indicated that the amplitude of half mode was one-fourth of first mode.
Modified Adams-Moulton predictor-corrector method in solving multibody dynamical systems
(2000)
Wu, SD
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Chiou, JC
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Lin, YC
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電控工程研究所
;
Institute of Electrical and Control Engineering
A modified Adnms-Moulton predictor-corrector method is proposed to solve multibody dynamical systems. The proposed method is obtained by combining an Adams-Bashforth predictor method and an Adams-Moulton corrector method with derived weighting coefficients. With the modification, the accuracy of the proposed method is almost one order of magnitude better than the Adams-Moulton predictor-corrector method with the same step size. Stability limits of the proposed method are also studied. Because the present method has greater stability limits than Adams-Moulton predictor-corrector methods, the proposed method has good robustness during the process of time integration. A crank-slider mechanism is used as an example to investigate the capability of the proposed method in solving multibody dynamic systems.