http://ieeexplore.ieee.org TOC Alert for Publication# 84 2013 May 16 22 2 C1 C2 135 22 2 C2 C2 124 2O₅) that has been recently reported as a dielectric for low-voltage electrowetting-on-dielectric (EWOD) devices, we find a severe deterioration in performance if the working liquid is actuated with positive dc voltage. In an effort to reduce the limitation of this otherwise attractive dielectric material for EWOD, proposed herein is a Ta₂O₅ layer prepared by anodizing a sputtered Ta₂O₅ film. This sputtered-anodized Ta₂O₅ allows the use of positive dc signals, while maintaining the low-voltage actuation for which the anodized Ta₂O₅ was originally introduced. All the EWOD tests were performed with a conductive liquid droplet in an air environment.]]> 22 2 253 255 411 2 emissions. Despite slight damage, the electrode lifetime exceeds 20 min. Results demonstrate that this device is flexible and is able to achieve maskless patterning of hydrophilic patterns on flat and curved glass surfaces.]]> 22 2 256 258 439 22 2 259 261 356 Q ) for single-crystal silicon square-plate resonators in relation to their crystal orientation within the (100) plane. Results from both the Lamé and extensional modes oriented in the 〈110〉 and 〈100〉 axes are presented. Q appears to be dependent on orientation for the Lamé mode. In the extensional mode, there is no significant difference in Q between the two axes due to the dominance of anchor loss. These trends agree well with the brief theoretical analysis that we have described here to provide a quantitative basis for interpreting the trends between Q and orientation observed in our measurements.]]> 22 2 262 264 565 22 2 265 275 1476 22 2 276 284 807 22 2 285 294 2215 e₃₁ coefficients, which, for the sensors in this work, are in the range 8.7-9.3 C/m².]]> 22 2 295 302 1084 z-axis gyroscope in order to curb these errors: In particular, specific drive springs, which are very stiff in the sense direction, and a mechanical decoupling between drive and sense are indicated to decrease errors. Local dispersion of the width of beams has been assessed with a network of electrical test structures and leads to a local standard deviation of 3-6 nm at the scale of a MEMS gyroscope device. The optimized design enables to obtain a total error of less than 300^°/s on very compact z-axis gyroscopes with an area of mechanical part of 0.5 mm².]]> 22 2 303 308 585 3 package, a 0.2 cm³ pump architecture with 1.5 mm diameter cells in a 4 × 2 array reduces pressure from 1 Torr (133.3 Pa) to <; 200 mTorr (26.6 Pa) in about 10 h, and from 115 mTorr (15.3 Pa) to <; 10 mTorr (1.33 Pa) in 4 h. The rate of molecular removal in this range of pressures is 0.09 ×10¹³ to 1.17 ×10¹³ molecules/s. Experiments show that the architecture is capable of igniting and sustaining the plasma required for operating at a pressure at least as low as 1.5 μTorr (200 nPa). The advantage of the Penning cell architecture reported here in comparison to other chip-scale ion pump architectures is the drastically reduced operating pressures that can be achieved and maintained. The microdischarge requires 450-600 V applied across the device and consumes 100-250 mW. The Penning cell array architecture shows significant promise for power efficient high-vacuum pumping in chip-scale and smaller systems.]]> 22 2 309 317 1382 22 2 318 330 980 °C into a planar microfabrication process is enabled to build the 3-D spiral-coil SMA actuator in a self-assembled manner using a SiO₂ reset layer patterned on the SMA coil. The fabricated SMA structure yields an out-of-plane displacement of 466 μm in the cold state. The full actuation to the flat state is reached at 70°C upon tuning the field frequency to ~ 230 MHz with an RF output power of 0.7 W. The developed actuator is demonstrated to provide a maximum force of 30 mN. The temporal response of the actuator is revealed to be two to three times faster than that of previously reported wireless SMA actuators with separate heat sources.]]> 22 2 331 338 1632 22 2 339 348 2247 22 2 349 355 1135 °C for about 5 h, and complete removal of silicon in KOH. Finally, soft lithography is exploited to transfer the structures to PDMS maintaining the same aspect ratio and feature sizes of the original patterns in silicon. As a case example, an insulator-based dielectrophoresis (iDEP) device with 3-D constrictions has been developed that can operate at lower applied potentials compared with previously reported 2-D iDEP designs. Using the 3-D iDEP device, trapping of 2-μm and 500-nm polystyrene beads was achieved with an applied potential of 150 and 350 V, respectively, with more than 80% trapping efficiency.]]> 22 2 356 362 542 22 2 363 371 1010 22 2 372 385 601 22 2 386 394 1827 3 resonator is tunable from 15.2 GHz up to 16.5 GHz (analog tuning range) and up to 17.8-GHz range (digital tuning range) with an array of 75 MEMS fixed-fixed beams. The MEMS beams are biased against their own silicon substrate. This helps keep RF leakage at a minimum and permits high quality factors of 500-735 for the all-silicon configuration. By applying dynamic biasing waveforms, the MEMS tuners respond within 9 μs (actuation time) and 60 μs (release including settling time). To the best of the authors' knowledge, the presented resonator is more than 3 × smaller, achieves nearly 30% higher average quality factor, and is at least 10-100 × faster than state-of-the-art resonators based on similar technology, implemented in similar frequency ranges.]]> 22 2 395 405 2200 2 nanowire catalyst embedded silicon microelectromechanical systems (MEMS) H₂O₂ monopropellant microthruster has been demonstrated. Due to exothermic reaction process, sustenance of thrust generation does not require any heating of propellant thus minimizing electrical power requirement. The thruster device integrates inlet nozzle, microchannel, MnO₂ nanowire embedded reaction chamber, in-plane exit nozzle and a microheater in the silicon layer. Nozzle configuration and catalyst bed was designed using simple analytical equations to achieve complete decomposition of H₂ O₂ and maximum thrust force by controlling the propellant flow. Simulation of hydrogen peroxide decomposition process was carried out to evaluate the thermo-chemical characteristics. The MnO₂ nanowire has been obtained using a low-cost synthesis process and characterized using field emission scanning electron microscopy, Energy-dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray diffraction studies. Thruster fabrication using micromachining process and its testing have been briefly described. The device is capable to produce 1 mN thrust and specific impulse of 180 s using 50 wt.% concentrated H₂O₂ of flow rate 1.25 mg/s with total ignition energy of 44 J required for preheating the catalyst bed. Detailed thrust measurement was carried out with propellant mass flow rate for different throat area of exit nozzle, and the results were interpreted with theoretical model.]]> 22 2 406 417 1629 f₀). The observed scatter in the fatigue results of these microresonators is in part associated with the challenge in accurately calculating the local stress amplitudes. Despite that large scatter, the fatigue behavior of the 10 and 25 μm thick devices is similar. Particularly, the overall relative decrease rates in f₀ are well related to fatigue life (N_f) and can be used to predict N_f within a factor of 5, for N_f ranging from 10⁴ to 10¹⁰ cycles.]]> 22 2 418 429 1327 22 2 430 437 659 22 2 438 442 922 22 2 443 451 645 22 2 452 461 1991 22 2 462 470 1146 2 area mounted on a silicon frame. Each emitter is about 150-μm tall with a radius of curvature of about 15 μm at the tip.]]> 22 2 471 482 1884 Kx while maintaining low motion direction stiffness Ky over a large range of motion direction displacement. The resulting high (Kx/Ky) ratio mitigates the onset of sideways snap-in instability, thereby offering significantly greater actuation stroke compared with existing designs. Further improvement is achieved by reinforcing the individual beams in this flexure mechanism. While the traditional paired double parallelogram (DP-DP) flexure design with comb gap G = 3 μm and flexure beam length L₁ = 1 mm results in a 50- μm stroke before snap-in, the reinforced C-DP-DP design with the same comb gap and flexure beam length achieves a stroke of 141 μm. Furthermore, this C-DP-DP flexure design provides a 215- μm stroke with G = 4 μm and a 245-μm stroke with G = 6 μm. The presented work includes closed-form stiffness expressions for the reinforced C-DP-DP flexure, a design procedure for selecting dimensions of the overall comb-drive actuator, microfabrication of some representative actuators, and experimental measurements demonstrating the large stroke.]]> 22 2 483 494 2060 22 2 495 505 1095 22 2 506 506 934 22 2 507 507 594 22 2 508 508 653 22 2 C3 C3 338