IEEE Transactions on Industrial Electronics

Volume 56, Number 4, April 2009 Access to the journal on IEEE XPLORE IE Transactions Home Page

56.4.1	"Table of Contents," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. C1-910, April 2009. Abstract Link Full Text Abstract: Not Available
56.4.2	"IEEE Transactions on Industrial Electronics publication information," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. C2-C2, April 2009. Abstract Link Full Text Abstract: Not Available Special Section on Advances in Micro-Electromechanical Systems
56.4.3	"Guest Editorial," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 911-912, April 2009. Abstract Link Full Text Abstract: Not Available Special Section Papers
56.4.4	R. DeanJr., A. Luque, "Applications of Microelectromechanical Systems in Industrial Processes and Services," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 913-925, April 2009. Abstract Link Full Text Abstract: This paper presents a review of the current and future applications of microelectromechanical systems (MEMS) in the industrial sector. A historical perspective of the origin and development of MEMS is presented, as well as the traditional and innovative fabrication techniques. The process flow of computer-aided design and simulation is also discussed. After that, several of the most important applications of microsystems in the manufacturing and production sectors are enumerated and described. Two case examples are discussed in depth: gyroscopes for the measurement of angular movement, where the basic laws are provided, and a thorough review of existing devices is presented; and particle production devices for the generation of micrometer-sized droplets, where the two most common techniques are compared, along with the challenges that remain open. Finally, some conclusions and perspectives for the future are presented and discussed.
56.4.5	H.-M. Yeh, K.-S. Chen, "Development of a Digital-Convolution-Based Process Emulator for Three-Dimensional Microstructure Fabrication Using Electron-Beam Lithography," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 926-936, April 2009. Abstract Link Full Text Abstract: Although electron-beam lithography has been demonstrated to be feasible in creating 3-D micropolymer structures, the proximity effect due to forward and backward scatterings usually makes it difficult to precisely determine the distribution of electron irradiation. The process design for creating the desired shape still largely depends on a trial-and-error basis. Therefore, in order to reduce the cost and to accelerate product development, it is important to utilize computer-aided design tools. A method, called as element growth method, which is based on digital convolution approach, is developed and presented under an OpenGL environment to reduce the cost and the developmental period for fabrication. By using such a convolution approach, this emulator converts the processing parameters into a final spatial-dosage distribution and subsequently into the final geometry of structures. In addition, a physically based kernel function is also proposed and used. Examples of 3-D microstructures such as the microlens are presented. By these tools, it is possible to provide guidelines for optimizing the fabrication process and to reduce the cost for the related e-beam lithography-based 3-D fabrication.
56.4.6	Z. Fan, J. Liu, T. Sorensen, P. Wang, "Improved Differential Evolution Based on Stochastic Ranking for Robust Layout Synthesis of MEMS Components," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 937-948, April 2009. Abstract Link Full Text Abstract: This paper introduces an improved differential evolution (DE) algorithm for robust layout synthesis of microelectromechanical system components subject to inherent geometric uncertainties. A case study of the layout synthesis of a comb-driven microresonator shows that the approach proposed in this paper can lead to design results that meet the target performance and are less sensitive to geometric uncertainties than the typical designs. It is also demonstrated that the algorithm proposed in this paper cannot only obtain better results than the standard DE algorithm but also outperform some other state-of-the-art algorithms in constrained optimization.
56.4.7	C. Wen, C. Zhu, Y. Ju, Y. Qiu, H. Xu, W. Lu, "Optimal Frequency Band Design Scheme of Dyadic Wavelet Processor Array Using Surface Acoustic Wave Devices," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 949-955, April 2009. Abstract Link Full Text Abstract: In this paper, the relationship between the center frequency and radius of bandwidth and its effect on the frequency band characteristics of dyadic wavelet processor array using surface acoustic wave (SAW) devices are studied, and an optimal frequency band design scheme is proposed. For an arbitrary scale wavelet processor, we proposed that the center frequency is defined to three times of the radius of frequency bandwidth. The frequency band design scheme ensures that the frequency band coverage factor is equal to 100% at $-$3 dB, which avoid the signal loss caused by the discrete frequency band and the device waste caused by the redundant frequency band. With the frequency band design scheme, an experiment of implementing a dyadic wavelet processor array using SAW devices with five scales is presented. Experimental results confirm that the frequency band coverage factor equals 100% at $-$3 dB without discrete and redundant frequency band.
56.4.8	L. Dong, D. Avanesian, "Drive-Mode Control for Vibrational MEMS Gyroscopes," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 956-963, April 2009. Abstract Link Full Text Abstract: This paper presents a novel design methodology and hardware implementation for the drive-mode control of vibrational micro-electro-mechanical systems gyroscopes. Assuming that the sense mode (axis) of the gyroscope is operating under open loop, the drive-mode controller compensates an undesirable mechanical spring-coupling term between the two vibrating modes, attenuates the effect of mechanical–thermal noise, and most importantly, forces the output of the drive mode to oscillate along a desired trajectory. The stability and robustness of the control system are successfully justified through frequency-domain analysis. The tracking error between the real output and the reference signal for the drive mode is proved to be converging with the increase of the bandwidth of the controller. The controller is first simulated and then implemented using field-programmable analog array circuits on a vibrational piezoelectric beam gyroscope. The simulation and experimental results verified the effectiveness of the controller.
56.4.9	J.-Y. Chen, J.-B. Zhou, G. Meng, W.-M. Zhang, "Evaluation of Eddy-Current Effects on Diamagnetic Bearings for Microsystems," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 964-972, April 2009. Abstract Link Full Text Abstract: Diamagnetic materials could be utilized with permanent magnets to offer a simple passive solution to microbearings as a result of scale reduction. In this paper, we investigate the eddy-current effect on the performance of diamagnetic bearings. Due to the good electrical conductivity of some of diamagnetic materials or the intentionally introduced eddy-current damper for vibration control, eddy current could be induced in the diamagnetic bearing with viscous forces opposing the relative motion between the rotor and the stator. Such damping mechanism is analyzed with a thin-sheet model and the image method and compared with that due to aerodynamic effects so as to give an idea of its significance at the microscale. Following the calculation, extracted damping coefficients are employed in a rotordynamic model to investigate their influence on dynamic behaviors of the bearing. Results indicated that damping provided by eddy-current effects has pros and cons for the performance of the diamagnetic bearing which involves rotational motion. Finally, rundown characteristics of the bearing are evaluated, and the implication for operation scheme is discussed.
56.4.10	A. Izadian, P. Khayyer, P. Famouri, "Fault Diagnosis of Time-Varying Parameter Systems With Application in MEMS LCRs," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 973-978, April 2009. Abstract Link Full Text Abstract: Multiple-model adaptive estimation (MMAE) is a well-known technique used for model matching of deterministic parameter systems. This technique can be used in fault diagnosis by allocating a model to each type of fault. In each contingency, the model that represents the behavior of the actual system can indicate the type of fault occurrence. Kalman filters are generally used in modeling and residual-signal generation of time-invariant systems. Slowly time-varying parameter systems, however, require a system identification unit in addition to the model-matching core. This paper utilizes the least square forgetting-factor technique in parameter identification of slowly time-varying systems and combines it with MMAE for fault-diagnosis applications in microelectromechanical-systems (MEMS) lateral comb resonators (LCRs). Prescheduled faults were designed for simulations and experimentally examined in real-time implementations of estimation-based diagnosis technique for two fabricated MEMS LCRs. It is shown that the application of a system identification unit significantly increases the performance of the fault diagnosis in MEMS devices.
56.4.11	B. Jang, A. Hassibi, "Biosensor Systems in Standard CMOS Processes: Fact or Fiction?," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 979-985, April 2009. Abstract Link Full Text Abstract: In this paper, we discuss the advantages and limitations of using standard complementary metal–oxide–semiconductor (CMOS) fabrication processes for the design of integrated affinity-based biosensor systems. In particular, we examine the compatibility of CMOS with various assaying techniques, detection modalities, and the possibility of fabricating their transducer structures on-chip.
56.4.12	L. Li, D. Uttamchandani, "Flip-Chip Distributed MEMS Transmission Lines (DMTLs) for Biosensing Applications," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 986-990, April 2009. Abstract Link Full Text Abstract: Design and characterization of a flip-chip distributed MEMS transmission line (DMTL) are presented. The concept of using this DMTL as a biosensor is then introduced. Radio frequency experiments on the DMTL loaded with “biosamples” have been conducted using the most accessible materials, namely, deionized water and aqueous solutions of salts. Results show that the reflection coefficient $(S_{11})$ of the solution-loaded DMTL is very sensitive to the salt concentration of the solution in the low-frequency ranges of 10 MHz–1 GHz and 3–4.5 GHz. At high frequencies, the relative dielectric constant of the biosample can also be quantitatively determined from the impedance of the DMTL.
56.4.13	K. Takahashi, E. Bulgan, Y. Kanamori, K. Hane, "Submicrometer Comb-Drive Actuators Fabricated on Thin Single Crystalline Silicon Layer," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 991-995, April 2009. Abstract Link Full Text Abstract: Electrostatic comb-drive microactuators were fabricated by electron beam lithography on a 260-nm-thick silicon layer of a silicon-on-insulator wafer. The actuators consisted of comb electrodes, springs, and a frame. Two kinds of microactuators with doubly clamped and double-folded springs were designed and fabricated. The comb electrode was as small as 2.5 $muhbox{m}$ wide and 8 $muhbox{m}$ long and was composed of 250-nm-wide, 260-nm-thick, and 2-$muhbox{m}$-long fingers. The air gap between the fingers was 350 nm. The spring was 250 nm wide, 260 nm thick, and 17.5 $muhbox{m}$ long, and the spring constant was 0.11 N/m. The force and displacement generated by the microactuator were $2.3 times 10^{-7} hbox{N}$ and 1.0 $muhbox{m}$, respectively. Applying an ac voltage, the oscillation amplitude became maximum at a frequency of 132 kHz. The mechanical and electrical characteristics of the fabricated actuators were investigated quantitatively.
56.4.14	T. Chen, L. Chen, L. Sun, X. Li, "Design and Fabrication of a Four-Arm-Structure MEMS Gripper," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 996-1004, April 2009. Abstract Link Full Text Abstract: This paper is focused on the design and fabrication of a four-arm-structure microelectromechanical systems gripper integrated with sidewall piezoresistive force sensors. Surface and bulk micromachining technologies are employed to fabricate the microgripper from a single-crystal silicon wafer (i.e., no silicon-on-insulator wafer is used). A vertical sidewall surface piezoresistor etching technique is used to form the side direction force sensors. The end effector of this gripper is a four-arm structure: two fixed cantilever arms integrated with piezoresistive sensors are designed to sense the gripping force. The resolution of the force sensor is in the micronewton range and, therefore, provides feedback of the forces that dominate the micromanipulation processes. An electrostatically driven microactuator is designed to provide the force to operate the other two movable arms. In this way, it creates a deflection of 25 $muhbox{m}$ at the arm tip, and the range of the operation is 30–130 $muhbox{m}$. Experimental results show that it can successfully provide force sensing and play a main role in preventing the damage of microparts in micromanipulation and microassembly tasks.
56.4.15	W. Choi, M. Akbarian, V. Rubtsov, C.-J. Kim, "Microhand With Internal Visual System," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1005-1011, April 2009. Abstract Link Full Text Abstract: A pneumatically operated four-fingered micromanipulator (a “microhand”) with a fiber-based internal visual system is developed using microelectromechanical systems fabrication techniques. This “seeing” microhand transfers images generated by the optical system equipped at the palm of the microhand to an operator via an optical fiber bundle to provide the shape and distal information of objects of interest. The use of illuminating fibers along with the optical bundle enables the microhand's operation even in light-deficient environments. Such visual information informs the accurate relative location of the device and the status of manipulation to the operator in real time, who will take subsequent actions accordingly with an increased accuracy and efficiency. Embedding the fiber-based optical system inside the manipulator, instead of using an external camera setup for overall system monitoring, greatly reduces the size of the manipulator and helps increase maneuverability, particularly when operating in a space-limited work area. Tests have been conducted to verify the performance of the visually aided microhand to manipulate millimeter-sized objects in real time. Building on the ability of the UCLA microhand to gently handle irregular-shaped objects, this vision-enabled microhand is expected to provide more accurate manipulations and widen the window of applications.
56.4.16	M. M. Shalaby, Z. Wang, L. L.-W. Chow, B. D. Jensen, J. L. Volakis, K. Kurabayashi, K. Saitou, "Robust Design of RF-MEMS Cantilever Switches Using Contact Physics Modeling," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1012-1021, April 2009. Abstract Link Full Text Abstract: This paper presents the robust design optimization of an RF-MEMS direct contact cantilever switch for minimum actuation voltage and opening time, and maximum power handling capability. The design variables are the length and thickness of the entire cantilever, the widths of the sections of the cantilever, and the dimple size. The actuation voltage is obtained using a 3-D structural-electrostatic finite-element method (FEM) model, and the opening time is obtained using the same FEM model and the experimental model of adhesion at the contact surfaces developed in our previous work. The model accounts for an unpredictable variance in the contact resistance resulting from the micromachining process for the estimation of the power handling. This is achieved by taking the ratio of the root mean square power of the RF current (“signal”) passing through the switch to the contact temperature (“noise”) resulting from the possible range of the contact resistance. The resulting robust optimization problem is solved using a Strength Pareto Evolutionary Algorithm, to obtain design alternatives exhibiting different tradeoffs among the three objectives. The results show that there exists substantial room for improved designs of RF-MEMS direct-contact switches. It also provides a better understanding of the key factors contributing to the performances of RF-MEMS switches. Most importantly, it provides guidance for further improvements of RF-MEMS switches that exploit complex multiphysics phenomena.
56.4.17	M. M. Shalaby, M. A. Abdelmoneum, K. Saitou, "Design of Spring Coupling for High-$Q$ High-Frequency MEMS Filters for Wireless Applications," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1022-1030, April 2009. Abstract Link Full Text Abstract: A second-order microelectromechanical systems (MEMS) filter with high selectivity and sharp rolloff is required in wireless transceivers used in dense wireless sensor networks (WSNs). These sensors are expected to replace existing wired sensors used in industrial-plant management and environmental monitoring. These filters, together with MEMS-based oscillators and mixers, are expected to replace off-chip components and enable the development of a single-chip transceiver. Such a transceiver will leverage the integrated MEMS components' characteristics to operate at lower power and, hence, longer battery life, making autonomous WSNs more feasible in a wider range of applications. As a result, this paper presents the design and optimization of the coupling beam of wineglass-mode micromechanical disk filters using simulated annealing. The filter under consideration consists of two identical wineglass-mode disk resonators, mechanically coupled by a flexural-mode beam. The coupled two-resonator system exhibits two mechanical-resonance modes with closely spaced frequencies that define the filter passband. A constraint is added on the beam length to eliminate the effect of the coupling-beam mass on the filter's resonant frequency. A new process flow is proposed to realize self-aligned overhanging coupling beams designed in this paper.
56.4.18	J.-Y. Choi, J. Ruan, F. Coccetti, S. Lucyszyn, "Three-Dimensional RF MEMS Switch for Power Applications," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1031-1039, April 2009. Abstract Link Full Text Abstract: This paper introduces a new concept in 3-D RF microelectromechanical systems switches intended for power applications. The novel switch architecture employs electrothermal hydraulic microactuators to provide mechanical actuation and 3-D out-of-plane silicon cantilevers that have both spring action and latching mechanisms. This facilitates an off-state gap separation distance of 200 $muhbox{m}$ between ohmic contacts, without the need for any hold power. Having a simple assembly, many of the inherent problems associated with the more traditional suspension-bridge and cantilever-type-beam architectures can be overcome. A single-pole single-throw switch has been investigated, and its measured on-state insertion and return losses are less than 0.3 dB up to 10 GHz and greater than 15 dB up to 12 GHz, respectively, while the off-state isolation is better than 30 dB up to 12 GHz. The switch works well in both hot- and cold-switching modes, with 4.6 W of RF power at 10 GHz and without any signs of degradation to the ohmic contacts.
56.4.19	B.-H. Jang, H.-Y. Huang, W. Fang, "A Novel Zero-Insertion-Force (ZIF) Micro $(mu)$ -Connector: Design, Fabrication, and Measurements," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1040-1047, April 2009. Abstract Link Full Text Abstract: This paper presents the design, fabrication, and measured properties of a novel zero-insertion-force (ZIF) micro $(mu)$-connector. The proposed ZIF $mu$-connector is shown to remedy a number of problems in the existing microelectromechanical-system-based connectors, such as the wearing effect, the poor signal integrity for high-speed signal transmission, and the lack of latch design. The three-mask and silicon-on-insulator wafers are designed for the simultaneous fabrication of terminals and latches. Prototype connectors are demonstrated with five 1800-${rm mu}hbox{m}$-long, 100- ${rm mu}hbox{m}$-wide, and 2-${rm mu}hbox{m}$ -high terminals on a 150-${rm mu}hbox{m}$ pitch. The terminals and latches are actuated by electrostatic force to avoid the wearing and kinking during the mating process. The terminal is a multimorph cantilever to form a hooklike out-of-plane shape. The controlled shape of the terminal provides a reliable contact at the interface. The properties of the proposed ZIF $mu$-connector are measured and analyzed, including the out-of-plane shape of the terminal, driving voltage, dc contact resistance, and the RF characteristics. The potential applications of the ZIF $mu$-connector include the fine-pitch high-speed interconnection, 3-D reworkable packaging, and the performance enhancement of many existing $mu$-connectors.
56.4.20	L. Garbuio, M. Lallart, D. Guyomar, C. Richard, D. Audigier, "Mechanical Energy Harvester With Ultralow Threshold Rectification Based on SSHI Nonlinear Technique," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1048-1056, April 2009. Abstract Link Full Text Abstract: Harvesting energy from ambient sources has become of great importance these last few years. This can be explained not only by advances in microlectronics and energy harvesting technologies, but also by a growing industrial demand in wireless autonomous devices. In this field, piezoelectric elements offer outstanding performances, thanks to their high power density that makes them suitable for integrated microgenerators. However, such a domain still offers challenges to the research community. Particularly, embedding piezoelectric inserts as MEMS components raises the issue of low voltage output. Classical energy harvesting interfaces that feature bridge rectifier suffer from threshold voltage introduced by such discrete components, therefore compromising their use in real-life applications. In this paper is presented a new energy harvesting circuit that operates with ultralow voltage output, by the use of a magnetic voltage rectifier that does not present significant voltage gap. Experimental measurements performed on a simple transducer confirm theoretical predictions, and show that the proposed architecture operates well even for low-level vibrations, outperforming all known energy interfaces. Particularly, it is theoretically and experimentally shown that such an interface provides a gain greater than 50 compared to classical energy harvesting structures.
56.4.21	C.-D. Liao, J.-C. Tsai, "The Evolution of MEMS Displays," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1057-1065, April 2009. Abstract Link Full Text Abstract: Due to the advancement of microoptoelectromechanical systems and microelectromechanical systems (MEMS) technologies, novel display architectures have emerged. One of the most successful and well-known examples is the Digital Micromirror Device from Texas Instruments, a 2-D array of bistable MEMS mirrors, which function as spatial light modulators for the projection display. This concept of employing an array of modulators is also seen in the grating light valve and the interferometric modulator display, where the modulation mechanism is based on optical diffraction and interference, respectively. Along with this trend comes the laser scanning display, which requires a single scanning device with a large scan angle and a high scan frequency. A special example in this category is the retinal scanning display, which is a head-up wearable module that laser-scans the image directly onto the retina. MEMS technologies are also found in other display-related research, such as stereoscopic (3-D) displays and plastic thin-film displays.
56.4.22	R. Smith, D. R. Sparks, D. Riley, N. Najafi, "A MEMS-Based Coriolis Mass Flow Sensor for Industrial Applications," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1066-1071, April 2009. Abstract Link Full Text Abstract: A microfluidic Coriolis mass flow sensor is discussed. The micromachined flow sensors are made using silicon tubes bonded onto a metallized glass substrate. True mass flow rates with an accuracy of better than $pm$0.5% were measured between 1 and 500 g/h. The sensor also provides a temperature and density output. The sensor output was resistant to pressure, temperature, vibration, fluid density, and viscosity. Unlike conventional steel Coriolis mass flowmeters, microelectromechanical-systems-based sensors are immune to external vibration. Applications for these low-flow-rate devices include chemical mixing, additives, biotechnology, chromatography, pharmaceutical development, and other areas where extremely small volumes of liquids are mixed, studied, or metered and where shock and vibration are encountered.
56.4.23	Y. Yu, J. Ou, J. Zhang, C. Zhang, L. Li, "Development of Wireless MEMS Inclination Sensor System for Swing Monitoring of Large-Scale Hook Structures," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1072-1078, April 2009. Abstract Link Full Text Abstract: A modular wireless microelectromechanical system (MEMS) inclination sensor system (WMISS) is developed and tested for providing structural health monitoring of large-scale hook structures. The operating principle of a 3-D-MEMS-based dual-axis inclinometer is analyzed. A wireless MEMS sensor is integrated using sensing disposal, wireless communication, and power units. The WMISS is calibrated by using a laser displacement sensor in a pendular structure. The maximal error of the wireless MEMS inclination sensor is about 1%. The resolution is $pm 0.0025^{circ}$. With the new-type tuned mass damper control module, an experiment on a WMISS for the swing monitoring of a Lanjiang hook model is developed. Experimental results indicate that the developed WMISS is highly precise, convenient, stable, and low cost and has long range, and thus, a WMISS can accurately and conveniently monitor the swing of a Lanjiang hook model.
56.4.24	B.-H. Kim, J.-B. Kim, J.-H. Kim, "A Highly Manufacturable Large Area Array MEMS Probe Card Using Electroplating and Flipchip Bonding," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1079-1085, April 2009. Abstract Link Full Text Abstract: A highly manufacturable microelectromechanical systems (MEMS) probe card was developed by using flipchip bonding technology, which is applicable to large area array bonding ranging from 2- to 8-in substrates. A cantilever-type probe structure for an actual device was electroplated with nickel–cobalt and was bonded with nickel bump, which anchored on the ceramic substrate. Gold–tin (AuSn) was used as the material of flipchip bonding between the cantilever beam and bump. Flipchip bonding itself is not a new technology, but combining it with a MEMS probe card is a novel technique in large area bonding because of the high reflow temperature (280 $^{circ}hbox{C}$, $ hbox{Au}_{80}hbox{Sn}_{20}$). Various parallelism bonding processes were used to find the best bonding method. The MEMS probe card was designed to achieve a deflection of 50 $ muhbox{m}$ when 2 gram force (gf) was applied and to keep elasticity up to a deflection of 150 $muhbox{m}$. The specification of the probe card was for actual 12-in dynamic random access memory testing. The measured average contact force was 2.04 gf at a 50- $muhbox{m}$ overdrive. In addition, mechanical and electrical characteristics were also suitable for the actual device test.
56.4.25	J. Wang, Z. Tang, J. Li, F. Zhang, "A MicroPirani Pressure Sensor Based on the Tungsten Microhotplate in a Standard CMOS Process," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1086-1091, April 2009. Abstract Link Full Text Abstract: This paper reports a tungsten microhotplate fabricated in a standard CMOS process and the implementation of a MicroPirani pressure sensor with it. A monolithic constant-current circuit including an operational amplifier is used to bias the tungsten microhotplate to measure the gas pressure. The sensor shows a linear response to the gas pressure in the range of 1–100 Pa when driven by a constant current of 7 mA. In this regime, the sensitivity of the sensor is 0.23 mV/Pa, the linearity is 4.95%, and the hysteresis is 8.69%. The MicroPirani pressure sensor in this paper can be used in a medium-vacuum measurement. Because tungsten in a standard CMOS process has a large temperature coefficient regardless of the different manufacturing processes, the design of the tungsten microhotplate can be applied to other thermal-based sensors, even in different standard CMOS processes.
56.4.26	D. E. Mouzakis, D. Dimogianopoulos, D. Giannikas, "Contact-Free Magnetoelastic Smart Microsensors With Stochastic Noise Filtering for Diagnosing Orthopedic Implant Failures," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1092-1100, April 2009. Abstract Link Full Text Abstract: A novel contact-free magnetoelastic microsensor for diagnosing failing orthopedic implants is introduced. It uses an implant-embedded 30-$muhbox{m}$-thick MetGlas-2826 film and a sensing coil placed 30 mm away from the film. Implant loading generates thin-film magnetoelastic response, passively (contact-free) detected as voltage by the coil. A specific integrated stochastic nonlinear filter performs data denoising, and a decision-making module concludes (via data assessment) on the health state of the implants. The sensor is successfully validated in vitro on an external fixation system and a hip prosthesis implant, respectively.
56.4.27	M. E. Kiziroglou, C. He, E. M. Yeatman, "Rolling Rod Electrostatic Microgenerator," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1101-1108, April 2009. Abstract Link Full Text Abstract: The difficulty of maximizing the proof mass, and lack of broadband operation, are key issues for miniaturized energy-harvesting devices. Here, a novel electrostatic energy harvester is presented, employing an external free-rolling proof mass to address these issues. A description of the operating principle is given, and the kinetic dynamics of the cylinder are analyzed. The electrostatics of the system are simulated, identifying the device performance for different dielectric dimensions and surface specifications. The fabrication of a prototype device is presented, and physical characterization results demonstrate a successful fabrication technique for dielectric sizes down to 100 nm. Capacitance measurements reveal a capacitance ratio of 4 and are in agreement with simulation results. A voltage gain of 2.4 is demonstrated. The device is suitable for energy harvesting from low-frequency high-amplitude ambient motion sources such as the human body.
56.4.28	E. Dumsong, N. Afzulpurkar, A. Tuantranont, "Design, Analytical Modeling, and Simulation of Wire-Free Walking Scratch-Drive Microrobot," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1109-1120, April 2009. Abstract Link Full Text Abstract: This paper describes the design, modeling, and simulation of a prototype wire-free walking scratch-drive microrobot with the dimensions of $365 muhbox{m} times 78 muhbox{m}$ . The microrobot consists of three scratch-drive actuators and two steering arms. The motion is controlled by delivering power via a capacitive coupling, with an underlying electric grid, to the microrobot. This way, the microrobot can move freely without connected wire for power supply. A globally controllable system is provided by a finite-state machine. The behavior of this microrobot using novel accurate analytical methods and the finite-element method simulation has been investigated. An automatic release mechanism is provided for mass production.
56.4.29	A. A. Ramadan, T. Takubo, Y. Mae, K. Oohara, T. Arai, "Developmental Process of a Chopstick-Like Hybrid-Structure Two-Fingered Micromanipulator Hand for 3-D Manipulation of Microscopic Objects," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1121-1135, April 2009. Abstract Link Full Text Abstract: The development of a chopstick-like two-fingered micromanipulator based on a hybrid mechanism is presented. The microhand consists of two 3-prismatic–revolute–spherical (PRS) parallel modules connected serially in a mirror image style. Each module has a long glass pipette as an end effector. The development process consists of three phases. In the first phase, analysis and mathematical modeling, a novel solution of the inverse kinematics problem (IKP) of a 3-revolute–prismatic–spherical (RPS) parallel module, is derived and applied with proper modification to the case of 3-PRS of the proposed mechanism. The solution is extended to the two-fingered hybrid mechanism of the microhand. In the optimization and design phase, the optimization of the chosen design parameters of a theoretical 3-PRS parallel module is carried out using two approaches: discretization method and genetic algorithms. Based on the optimal design parameters, a CAD model of the 3-PRS finger module is built, and a complementary optimization step using the ANSYS Workbench program is carried out to determine suitable characteristics of the pin flexure hinge. Finally, the total CAD model of the two-fingered hand is built. In the realization and implementation phase, the description of the hardware system of the two-fingered microhand prototype is presented. The program description, calibration method, practical Jacobian matrices, practical workspace, and error analysis of the prototype are discussed. Single-Phase Electronics
56.4.30	C. S. Moo, K. H. Lee, H. L. Cheng, W. M. Chen, "A Single-Stage High-Power-Factor Electronic Ballast With ZVS Buck–Boost Conversion," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1136-1146, April 2009. Abstract Link Full Text Abstract: This paper proposes a novel single-stage high-power-factor electronic ballast via the integration of a derivative buck–boost converter and a half-bridge resonant inverter. The derivative buck–boost converter employs two coupled inductors with an appropriate turn ratio to conduct the current from the input line source into the designated power switches. With the tactful topology and delicately designed circuit parameters, both the active power switches of the resonant inverter can retain the zero voltage switching, resulting in a high circuit efficiency. A prototype circuit designed for a T8-36W rapid-start fluorescent lamp was built and tested to verify the analytical predictions, and satisfactory results were obtained experimentally.
56.4.31	E. H. Ismail, "Bridgeless SEPIC Rectifier With Unity Power Factor and Reduced Conduction Losses," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1147-1157, April 2009. Abstract Link Full Text Abstract: In this paper, a new bridgeless single-phase ac–dc converter with an automatic power factor correction (PFC) is proposed. The proposed rectifier is based on the single-ended primary inductance converter (SEPIC) topology and it utilizes a bidirectional switch and two fast diodes. The absence of an input diode bridge and the presence of only one diode in the flowing-current path during each switching cycle result in less conduction loss and improved thermal management compared to existing PFC rectifiers. Other advantages include simple control circuitry, reduced switch voltage stress, and low electromagnetic-interference noise. Performance comparison between the proposed and the conventional SEPIC PFC rectifier is performed. Simulation and experimental results are presented to demonstrate the feasibility of the proposed technique.
56.4.32	J.-M. Kwon, W.-Y. Choi, B.-H. Kwon, "Single-Switch Quasi-Resonant Converter," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1158-1163, April 2009. Abstract Link Full Text Abstract: A single-switch quasi-resonant converter is proposed to obtain high efficiency. Using a variable switching frequency control, this converter is continuously operated at the critical conduction mode for soft switching of the power semiconductor switch. By the resonance, the proposed converter reduces the turn-on loss of the switch without additional active switches and alleviates the reverse-recovery losses of the rectifying diodes. Furthermore, the voltage stress of the rectifying diodes due to the output series resonant circuit is clamped to the output voltage. Experimental results for the 48-V/160-W converter at the variable switching frequency are obtained to show the performance of the proposed converter.
56.4.33	S. K. Mishra, K. D. T. Ngo, "Dynamic Characterization of the Synthetic Ripple Modulator in a Tightly Regulated Distributed Power Application," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1164-1173, April 2009. Abstract Link Full Text Abstract: Hysteretic modulators have superior dynamic performance, and they also help reduce the number of output capacitors without sacrificing the transient response. For proper hysteretic operation, the voltage ripple is required to be piecewise linear and noise free. With modern computational integrated circuits lower supply voltage with tight regulation requirements, the output voltage ripple is both small and noisy. The synthetic ripple modulator (SRM) allows proper hysteretic operation even with a small and corrupted output voltage ripple. This paper discusses the dynamic behavior of the SRM. Small-signal characteristics of the modulator are derived. An easy-to-use numerically efficient model has been developed to accurately predict the small- and large-signal behavior of the converter driven by the SRM. The model is able to predict the small-signal behavior of the SRM up to half the switching frequency with sufficient accuracy. It can predict the same large-signal responses as real-time simulation, but at two orders of magnitude less in computation time. Laboratory tests on a 1.8 V/20 A single-phase prototype shows good correlation between experimental results and theoretical predictions both in frequency and time domain.
56.4.34	X. Ruan, W. Chen, L. Cheng, C. K. Tse, H. Yan, T. Zhang, "Control Strategy for Input-Series–Output-Parallel Converters," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1174-1185, April 2009. Abstract Link Full Text Abstract: The input-series–output-parallel (ISOP) converter, which consists of multiple dc–dc converter modules connected in series at the input and in parallel at the output, is an attractive solution for high input voltage and high power applications. This paper reveals the relationship between input voltage sharing (IVS) and output current sharing of the constituent modules of the ISOP converter. A novel IVS control strategy, which is decoupled with the output voltage regulation, is proposed. This control allows IVS and output voltage regulation to be designed independently. An ISOP converter, which uses the phase-shifted full-bridge (PS-FB) converter as the basic module, is considered. Based on the proposed control strategy, this ISOP converter together with the control circuit can be decoupled from several independent single-input and single-output systems. An ISOP converter consisting of three PS-FB modules is used to illustrate the design procedure, and a 3-kW experimental prototype is fabricated and tested. Multiphase Systems
56.4.35	F. Bradaschia, M. C. Cavalcanti, F. A. S. Neves, H. E. P. de Souza, "A Modulation Technique to Reduce Switching Losses in Matrix Converters," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1186-1195, April 2009. Abstract Link Full Text Abstract: This paper presents a modulation technique based on the generalized pulsewidth-modulation strategy for matrix converters. The proposed technique uses a discontinuous modulation to clamp each output leg of the converter during 120$^{circ}$ of the output voltage period, achieving a reduced number of switchings compared with the traditional modulation techniques. Aside from that, the major attraction of the proposed technique is an additional algorithm that lags the clamping of each output leg of the converter to synchronize it with the peak of the corresponding output current (load current), avoiding high switching losses (switching at high currents). Therefore, this technique reduces the number of switchings as well as guarantees only medium and low current switchings. Simulation and experimental results show the efficiency of the proposed technique.
56.4.36	F. J. C. Padilha, W. I. Suemitsu, M. D. Bellar, P. M. Lourenco, "Low-Cost Gate Drive Circuit for Three-Level Neutral-Point-Clamped Voltage-Source Inverter," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1196-1204, April 2009. Abstract Link Full Text Abstract: This paper presents a new hardware implementation of gate drive circuits applied to low-power neutral-point-clamped (NPC) multilevel three-phase inverters. The proposed circuit is based on commercially available MOS-gate driver ICs (MGDs) for large-scale applications, which may reduce the total cost of implementation of NPC inverters. Only one dc power supply is required to feed all the gate drivers for the three-phase system. Detailed design procedures are presented, which include the protection circuits for avoiding hazardous switching states of the power switches. Experimental results of a laboratory prototype demonstrate the validity of the proposed circuit. These results also suggest that for achieving safe operation of snubberless power switches during transients, a hybrid implementation of each NPC phase leg, consisting of MOSFETs with voltage ratings at half the dc bus voltage and of insulated gate bipolar transistors rated at the total dc bus voltage, is recommended. Renewable Energy Systems
56.4.37	L.-R. Chen, C.-S. Liu, J.-J. Chen, "Improving Phase-Locked Battery Charger Speed by Using Resistance-Compensated Technique," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1205-1211, April 2009. Abstract Link Full Text Abstract: In this paper, a resistance-compensated phase-locked battery charger (RC-PLBC) mathematical model is built, and its s-domain transfer function is also derived. The stable, safe, and nonovercharging conditions of the RC-PLBC are discussed, and many criteria are proposed. After that, a complete design procedure is presented for designing a fast and safe RC-PLBC. A prototype of RC-PLBC is designed and realized to verify the charging performance. Comparing with a typical PLBC, the charge speed of the proposed RC-PLBC is improved by 18%, and the safety is held on.
56.4.38	K. Jin, X. Ruan, M. Yang, M. Xu, "A Hybrid Fuel Cell Power System," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1212-1222, April 2009. Abstract Link Full Text Abstract: This paper proposes a hybrid fuel cell power system, which consists of a fuel cell, an isolated unidirectional converter, a bidirectional converter, an inverter, and a battery. The fuel cell and the battery are connected to the same voltage bus through an appropriate hybrid full-bridge LLC resonant unidirectional converter and a three-level buck/boost bidirectional converter, respectively. The battery is an auxiliary energy source, powers the load during the system's start state to make it easy for the system to cold start, and provides or absorbs the dynamic power when the load varies and the fuel cell cannot respond immediately, so the system dynamic characteristics are improved. Furthermore, the battery can also provide peak power at overload, so the power rating of the fuel cell can be decreased, which reduces the total system cost. In order to ensure that the system operates with high efficiency, this paper also proposes a power management control scheme, which controls the bidirectional converter operating under buck, boost, or shutdown mode according to the operation condition of the fuel cell and battery, so that the battery can be charged or discharged. The operation of the system during cold start and overload are analyzed in detail. A 1-kW fuel cell power system was built in the laboratory. Experimental results are shown to verify the theoretical analysis. Motors and Actuators
56.4.39	J. Scott, J. McLeish, W. H. Round, "Speed Control With Low Armature Loss for Very Small Sensorless Brushed DC Motors," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1223-1229, April 2009. Abstract Link Full Text Abstract: A method for speed control of brushed dc motors is presented. It is particularly applicable to motors with armatures of less than 1 $hbox{cm}^{3}$. Motors with very small armatures are difficult to control using the usual pulsewidth-modulation (PWM) approach and are apt to overheat if so driven. The technique regulates speed via the back electromotive force but does not require current-discontinuous drives. Armature heating in small motors under PWM drive is explained and quantified. The method is verified through simulation and measurement. Control is improved, and armature losses are minimized. The method can expect to find application in miniature mechatronic equipment. Drive Control
56.4.40	A. Gopinath, A. Mohamed A. S., M. R. Baiju, "Fractal Based Space Vector PWM for Multilevel Inverters—A Novel Approach," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1230-1237, April 2009. Abstract Link Full Text Abstract: A space vector pulsewidth-modulation (SVPWM) technique based on fractal approach for multilevel inverters is presented. This paper proposes a view that the space vector locations of multilevel inverters possess a fractal structure, and the properties of fractal structure together with the simplicity of fractal arithmetic are exploited to generate the SVPWM. The proposed method does not use any lookup tables for sector identification. The switching space vectors are also directly determined without using any lookup tables. The proposed scheme can be extended to an $n$-level inverter, and a generalized algorithm is also presented. The proposed scheme for generating SVPWM for multilevel inverters is explained for a five-level inverter, and experimental results are presented for a three-level inverter.
56.4.41	F.-J. Lin, Y.-C. Hung, S.-Y. Chen, "FPGA-Based Computed Force Control System Using Elman Neural Network for Linear Ultrasonic Motor," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1238-1253, April 2009. Abstract Link Full Text Abstract: A field-programmable gate array (FPGA)-based computed force control system using an Elman neural network (ENN) is proposed to control the mover position of a linear ultrasonic motor (LUSM) in this paper. First, the structure and operating principle of the LUSM are introduced. Then, the dynamics of the LUSM mechanism with the introduction of a lumped uncertainty, which include the friction force, are derived. Since the dynamic characteristics and motor parameters of the LUSM are nonlinear and time varying, a computed force control system using ENN is designed to improve the control performance for the tracking of various reference trajectories. The ENN with both online learning and excellent approximation capabilities is employed to estimate a nonlinear function including the lumped uncertainty of the moving table mechanism. Moreover, the Lyapunov stability theorem and the projection algorithm are adopted to ensure the stability of the control system and the convergence of the ENN. Furthermore, an FPGA chip is adopted to implement the developed control algorithm for possible low-cost and high-performance industrial applications. The experimental results show that excellent positioning and tracking performance are achieved, and the robustness to parameter variations and friction force can be obtained as well using the proposed control system.
56.4.42	J. A. Pontt, J. R. RodrÍguez, A. Liendo, P. Newman, J. Holtz, J. M. San Martin, "Network-Friendly Low-Switching-Frequency Multipulse High-Power Three-Level PWM Rectifier," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1254-1262, April 2009. Abstract Link Full Text Abstract: High-power converters for regenerative drives and distributed generation need a network-friendly operation, low harmonic conductive electromagnetic emission for low electromagnetic interference and high electromagnetic compatibility reaching high reliability and performance. Nevertheless, the converters must be controlled with low switching frequency in order to reduce the commutation losses. These two requirements can be satisfied if an optimal modulation strategy is used. The selective harmonic elimination (SHE) is one of the low-switching-frequency strategies most used today. However, this strategy only eliminates a reduced set of harmonic components from the input current. This paper presents a novel optimal modulation strategy whose objective is to reduce the total harmonic distortion of the input current. Six- and twelve-pulse three-level neutral-pointclamped pulsewidth modulation rectifiers are used in order to implement both modulation techniques. The results confirm the advantages of the proposed strategy, namely, less input current distortion and remarkable reduction of higher order harmonics compared with the SHE method, while keeping a low-switching behavior.
56.4.43	M. N. Uddin, S. W. Nam, "Development and Implementation of a Nonlinear-Controller-Based IM Drive Incorporating Iron Loss With Parameter Uncertainties," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1263-1272, April 2009. Abstract Link Full Text Abstract: This paper presents the development and real-time implementation of a nonlinear controller for the speed control of an induction motor (IM) drive. Neglecting the iron loss in an IM model causes performance deterioration, and there has been research to investigate and cope with this problem in the vector control of an IM. However, little work has been done in the area of the nonlinear control of an IM. In this paper, an adaptive backstepping-based nonlinear controller incorporating the iron loss is developed under the parameter uncertainties. To reduce the complexity in the design of the controller, the motor model is referenced to the rotor magnetizing current, and the controller is developed in the rotor-flux-oriented control scheme. The adaptive backstepping technique is utilized to estimate the parameters online and maintain the global stability of the drive through Lyapunov. The proposed controller is successfully implemented in real time using a digital signal processor board DS 1104 for a laboratory 1/3-hp IM. Both simulation and experimental results show that the proposed controller successfully achieves the rotor-speed-tracking objective and improves dynamic responses as compared to the one without parameter adaptation. Signal Processing and Control
56.4.44	L. Harnefors, "Implementation of Resonant Controllers and Filters in Fixed-Point Arithmetic," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1273-1281, April 2009. Abstract Link Full Text Abstract: Resonant controllers and filters are useful in voltage-source-converter control systems. Although the trend is toward implementation in floating-point arithmetic, fixed-point arithmetic is still of interest, but requires much greater care in the algorithm design. This paper covers some important issues, namely, choice of structure, design formulas, scaling, sensitivity, quantization-noise amplification, and suppression of overflow limit cycles. The results presented should be particularly helpful as design guidelines to practical engineers in a situation where one often resorts to trial and error.
56.4.45	B. Tavassoli, P. Jabehdar-Maralani, n. Rezaee, "Tuning of Control Systems Over CSMA Networks," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1282-1291, April 2009. Abstract Link Full Text Abstract: In this paper, control systems over soft real-time carrier sensing multiple access networks are considered. A precise modeling of the system is presented, and the effects of using the communication network are probabilistically characterized. The results can be used to study several control performance issues in the stochastic setting. In this paper, the expected value of a quadratic cost function is calculated, and the result is used for optimal controller tuning and performance analysis through an example. Diagnosis and Monitoring
56.4.46	M. I. Chacon-Murguia, J. I. Nevarez-Santana, R. Sandoval-Rodriguez, "Multiblob Cosmetic Defect Description/Classification Using a Fuzzy Hierarchical Classifier," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1292-1299, April 2009. Abstract Link Full Text Abstract: The complexity of classification tasks in computer vision applications has increased, as these systems have been adopted in more real-world applications. One of the hardest tasks to model by a computer system is related to achieving a human task based on subjective perception of the environment or goods. This paper presents a fuzzy classifier aimed to perform a subjective classification task, using the same criteria considered by a human inspector. The task consists on the description and classification of a cosmetic defect presented in ophthalmic lenses. The human inspector is modeled by a fuzzy hierarchical rule classifier (FHRC). The goal of the first stage is to obtain the description of the defect constituents. This information is then analyzed by the second stage to provide the final classification. The performance of the FHRC is 91.83% of correct classification in the single blob case and 81.48% in the multiblob. This performance can be considered acceptable, assuming that a human inspector has an estimated performance of 85%, with the advantages that the proposed system does not suffer from the disadvantages of a human inspector. The system also provides information of the defect constituents, which can be used to improve the fabrication process.
56.4.47	P. Barriuso, J. Dixon, P. Flores, L. Moran, "Fault-Tolerant Reconfiguration System for Asymmetric Multilevel Converters Using Bidirectional Power Switches," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1300-1306, April 2009. Abstract Link Full Text Abstract: Asymmetric multilevel converters can optimize the number of levels by using H-bridges scaled in the power of three. The shortcoming of this topology is that the H-bridges are not interchangeable, and then, under certain faulty conditions, the converter cannot operate. A reconfiguration system based on bidirectional electronic valves has been designed for three-phase cascaded H-bridge inverters. Once a fault is detected in any of the insulated gate bipolar transistors of any H-bridge, the control is capable to reconfigure the hardware keeping the higher power bridges in operation. In this way, the faulty phase can continue working at the same voltage level by adjusting its gating signals. Some simulations and experiments with a 27-level inverter, to show the operation of the system under a faulty condition, are displayed.
56.4.48	M. Jager, F. A. Hamprecht, "Principal Component Imagery for the Quality Monitoring of Dynamic Laser Welding Processes," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1307-1313, April 2009. Abstract Link Full Text Abstract: A popular technique to monitor laser welding processes is to record laser-induced plasma radiation with a highspeed camera. The recorded sequences are analyzed using pattern recognition systems. Since the raw data are too high dimensional to allow for an efficient learning, dimension reduction is necessary. The most common technique for dimension reduction in laser welding applications is to use geometric information of segmented objects. In contrast, we propose to adapt ideas from face recognition and to employ appearance-based features to describe the relevant characteristics of the recorded images. The classification performance of geometric and appearance-based features is compared on a representative data set from an industrial laser welding application. Hidden Markov models are used to capture the temporal dependences and to perform the classification of unlabeled sequences into an error-free and an erroneous class. We demonstrate that a classification system based on appearance-based features can outperform geometric features. Emerging Technology
56.4.49	P. Sen, C.-J. Kim, "Microscale Liquid-Metal Switches—A Review," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1314-1330, April 2009. Abstract Link Full Text Abstract: Microelectromechanical systems (MEMS) have constituted an active R&D area over the last two to three decades, with one of the earliest application topics being microswitches. Typical designs involve actuation of microscale flexural elements (e.g., beams and membranes) to make a short or an opening in the transmission (signal) line. However, the problem of reliability of these switches persisted due to the presence of a solid–solid contact. Inspired by the regular mercury switches that use liquid–solid contact to solve the problems, several researchers have been exploring the use of liquid metal (LM) in developing microscale switches. Over time, the following two different approaches have evolved: LM-wetted microswitches and LM-actuated microswitches. In this paper, we summarize the progress of both approaches over the last decade by reporting a series of LM microswitches, each with the mechanism, fabrication, and performance. In addition, the properties of various LMs and LM alloys and the issues of fabrication and packaging involving LM are presented to help understand the reported developments as well as to assist in designing future LM microswitches.
56.4.50	"Have you visited lately? www.ieee.org," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1331-1331, April 2009. Abstract Link Full Text Abstract: Not Available
56.4.51	"Quality without compromise," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. 1332-1332, April 2009. Abstract Link Full Text Abstract: Not Available
56.4.52	"IEEE Industrial Electronics Society Information," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. C3-C3, April 2009. Abstract Link Full Text Abstract: Not Available
56.4.53	"IEEE Transactions on Industrial Electronics information for authors," IEEE Trans. on Industrial Electronics, vol. 56, no. 4, pp. C4-C4, April 2009. Abstract Link Full Text Abstract: Not Available