http://ieeexplore.ieee.org TOC Alert for Publication# 84 2009 November 23 18 5 C1 C4 45 18 5 C2 C2 39 18 5 973 982 1822 18 5 983 989 848 18 5 990 997 1197 dc. In this region, specific pulse heights for different radiation species resulted. The amplification region strength which determines the device sensitivity to radiation energy can be tuned with the electrode separation distance. An electrode separation of 0.8 mm produced a count rate of 530 cpm for a ⁹⁰Sr beta source when compared to an off-the-shelf Geiger counter which produced 1500 cpm. Count rates as high as 15 300 were observed for the same radiation source with electrodes spaced closer than 0.5 mm. By using a novel microinjection ceramic molding and silver paste metallizing process, the batch fabrication of essentially disposable devices can be achieved.]]> 18 5 998 1003 552 deg about both x- and y-axes and displaces 480 mum in the z-axis, all at dc voltages that are less than 8 V. Dynamic testing of the micromirror shows that the thermal response time of each actuator is about 10 ms. Resonant frequencies of the piston and rotation motion are 336 and 488 Hz, respectively. The unique structural design of the device ensures that there is no lateral shift for the piston motion and no rotation-axis shift for the rotation scanning. With the large tip-tilt-piston scan ranges and low driving voltage, this type of device is very suitable for biomedical imaging and laser beam steering applications.]]> 18 5 1004 1015 1563 D" which is a measure of the gradual material degradation under cyclic loading. The fatigue damage model is then used to investigate the effects of microstructure randomness on the fatigue of MEMS. In this paper, three different types of randomness are considered: (1) randomness in the microstructure due to random shapes and sizes of the material grains; (2) the randomness in the material properties considering a normally (Gaussian) distributed elastic modulus; and (3) the randomness in the material properties considering a normally distributed resistance stress, which is the experimentally determined material property controlling the ability of a material to resist the damage accumulation. Thirty-one numerical models of MEMS specimens are considered under cyclic axial and bending loading conditions. It is observed that the stress-life results obtained are in good agreement with the experimental study. The effects of material inhomogeneity and internal voids are numerically investigated.]]> 18 5 1016 1031 1825 18 5 1032 1046 1183 0.6Ge_0.4 and a 10-nm-thick Si layer) are found to be 171.3deg/mum and 2.110 times 10^-6 Nmiddotm/N, respectively. The stiffness (0.033 N/m) is much smaller than that of bottom-up synthesized helical nanostructures, which is promising for high-resolution force measurement in nanoelectromechanical systems. To perform torque measurement, two atomic force microscope cantilevers are used for simultaneous characterization of axial and radial properties of the same nanostructure. An application related to 3-D imaging is shown in a scanning electron microscope. The ultracompact size makes it possible for DCHNBs to serve as rotary stages for creating 3-D scanning probe microscopes or microgoniometers.]]> 18 5 1047 1053 670 2 . This paper presents the results of using relatively high pressures (> 3.0 torr) for the purpose of MEMS processing, while characterizing the physical etching mechanism and its effects on the working Si substrate in relation to the allowed processing time. The observed etch rates for high-pressure release varied from 1.6 to 1.9 mum/min for applied pressures of 4.5-5.5 torr. The resulting roughness is shown to be primarily dependent on time, where the maximum average roughness is approximately 1.4 mum after 3000 s at 5.5 torr. Slightly anisotropic results are produced by the increased pressures, showing a 0.7 : 1.0 (vertical : lateral) etch rate, as well as some detrimental effects to the released structures. Furthermore, the use of etch windows are investigated in relation to etch rate when subjected to these high pressures.]]> 18 5 1054 1061 1785 x) produced by plasma-enhanced chemical vapor deposition, and a ductile material, i.e., evaporated aluminum (Al), were characterized. The extraction of the Young's modulus E, tensile strength sigma_u, mean tensile strength sigmatilde_u, and Weibull modulus m is demonstrated. Young's moduli thus obtained for the poly-Si, SiN_x, and Al films were 156.3plusmn 2.6, 112.2plusmn3.5, and 62.5plusmn 2.5 GPa, respectively. The SiN_x layers, which have a mean tensile strength sigmatilde_u of 2.084_-0.177 ^+0.169 GPa and m=5.9_-1.6 ^+1.8, are the strongest from the fracture point of view when compared to poly-Si with sigmatilde_u=1.382_-0.026 ^+0.023 GPa and m=17.3_-3.2 ^+3.5 and Al with sigmatilde_u=0.347plusmn0.013 GPa. In each case, the best estimate of the mean and the corresponding 90% confidence interval were evaluated using maximum likelihood estimation and the likelihood ratio method, respectively, on the basis of Gaussian- and Weibull statistics.]]> 18 5 1062 1076 1205 18 5 1077 1086 1047 in situ cellular traction force evolutions of cardiac myocytes were demonstrated by using this new conversion model. The results presented by this paper are believed to be useful for biologists who are interpreting similar physiological processes.]]> 18 5 1087 1099 1627 2 have been fabricated in order to validate the production process. These actuators achieve actuation forces of more than 0.1 N and strokes of 750 mum using pressurized air or water as driving fluid.]]> 18 5 1100 1104 570 18 5 1105 1117 1263 18 5 1118 1125 1083 18 5 1126 1136 871 18 5 1137 1148 890 9 cycles (10 h) with 2.7 times 10^-14 Joules of stiction equivalent energy while the 60degC, 20% RH showed the least stiction accrual rate with less than 2% failure for 2.26 times 10¹² cycles (1500 h). In general, the stiction was seen to increase with an increase in humidity while mechanical fatigue showed an increase with an increase in temperature. Atomic force microscopy topography imaging was used to assess physical wear at the contacting areas. The results revealed that there were not any discernable changes in the surface profile due to long periods of actuation.]]> 18 5 1149 1159 1808 18 5 1160 1160 411 18 5 C3 C3 400