Multi-step etching of three-dimensional sub-millimeter curved silicon microstructures with in-plane principal axis

2014 ◽  
Vol 114 ◽  
pp. 78-84 ◽  
Author(s):  
Yasser M. Sabry ◽  
Diaa Khalil ◽  
Bassam Saadany ◽  
Tarik Bourouina
2011 ◽  
Vol 22 (1) ◽  
pp. 015015 ◽  
Author(s):  
S Azimi ◽  
M B H Breese ◽  
Z Y Dang ◽  
Y Yan ◽  
Y S Ow ◽  
...  

1995 ◽  
Vol 7 (3) ◽  
pp. 200-203 ◽  
Author(s):  
Masayoshi Esashi ◽  

Packaged micromechanical sensors were fabricated using bonded glass-silicon microstructures. These are integrated, resonant, or force-balancing sensors. Distributed electrostatic microactuator (DEMA) and three-dimensional microfabrication methods were developed.


Geophysics ◽  
1986 ◽  
Vol 51 (9) ◽  
pp. 1819-1829 ◽  
Author(s):  
G. A. LaTorraca ◽  
T. R. Madden ◽  
J. Korringa

The eigenstate analysis of Lanczos, also known as singular value decomposition (SVD), is used to define eight parameters which uniquely describe the magnetotelluric impedance Z. These parameters are independent of a priori assumptions about Z and can be interpreted in terms of three‐dimensional conductivity structures. Through SVD, the impedance is represented by two characteristic states. These states consist of two pairs (E and H) of complex vectors and two corresponding, real, singular values which together describe the extremal properties of Z. The singular values are the maximum and minimum |E|/|H| ratios possible at the observation site and therefore yield the true maximum and minimum apparent resistivities. We use a variation of SVD analysis by incorporating phases in the singular values, which are then called characteristic values. These phases reflect the delay (caused by the earth’s conductivity) of the electric fields relative to their associated magnetic fields. In this analysis of Z, the characteristic values contain four parameters, two singular values and two phases. The characteristic vectors contain the remaining four parameters, two principal axis directions and two ellipticities. The principal axis directions for the E and H vectors need not be at right angles as in biorthogonal analysis. The deviation of these axes from orthogonality is called the “skew angle” S. From a model by Park, we have found S to be closely related to distortions in the telluric current system caused by current gathering due to a good conductor. From the same model, we have found the ellipticity parameters to be the largest in regions of high current distortion and at the shorter periods. Consequently, we speculate that the ellipticity parameters are associated with local induction.


1997 ◽  
Vol 119 (4B) ◽  
pp. 756-765 ◽  
Author(s):  
S. Bedi ◽  
S. Gravelle ◽  
Y. H. Chen

Machining complex three dimensional surfaces is a challenging task. This paper presents two methods of machining these surfaces on a 4 and 5 axis machine, using a toroidal shaped cutter. The methods propose to align the principal axis of curvature of the machining surface with that of the machined surface in order to increase the volume of material removed. The increase in material removal at a point reduces the scallop height. Thus, fewer passes are required to achieve the same surface finish.


1992 ◽  
Vol 82 (1) ◽  
pp. 148-163
Author(s):  
Yoshimitsu Fukushima ◽  
Shigeo Kinoshita ◽  
Haruo Sato

Abstract Seismograms from small events in the southern Kanto region have been recorded by a seismometer installed in a 732-m-deep borehole at Chikura observatory, Japan, where mudstone of early Pliocene age is found from the ground surface to the bottom of the borehole. Strong phases occurring 1.5 ∼ 1.6 sec after the S-wave arrival were interpreted as reflections at the ground surface. Ray path directions of the incident S waves were determined from the minimum principal axis of the three-dimensional trajectory ellipsoid, which represents the particle motion for a head wave of S phase. Transverse horizontal SH components were used to estimate the Q−1 value for S waves. Assuming the free surface acted as an 100% reflector for the SH waves and the incident SH phase as an input and the reflected phase as an output, we calculated system functions. The Q−1 value was measured from the transfer characteristics between the incident and the reflected phases in a single seismogram, thus no corrections were necessary for source or site (including instrument) effects. If we applied a power law model, the following relationship was obtained from the regression analyses of 20 events: log 10 ( Q − 1 ) = ( − 0.52 ± 0.48 ) ⋅ log 10 ( f ) − ( 1.28 ± 0.22 ) ( 1.0 < f < 5.0 Hz ) , where f is frequency in Hz and error values are the 95% confidence levels of the regression coefficients.


2012 ◽  
Vol 1 (33) ◽  
pp. 65 ◽  
Author(s):  
Takaaki Uda ◽  
Masumi Serizawa ◽  
Shiho Miyahara

In a slender water body with a large aspect ratio, the angle between the direction normal to the shoreline and the wave direction exceeds 45°, resulting in the emergence of cuspate forelands and the subdivision of a lake, because wind fetch along the principal axis becomes long. In this study, the BG model (a three-dimensional model for predicting beach changes based on Bagnold’s concept) was applied to this problem. The 3-D subdivision process of a long slender water body was predicted.


Geophysics ◽  
1978 ◽  
Vol 43 (6) ◽  
pp. 1167-1175 ◽  
Author(s):  
F. W. Jones ◽  
K. Vozoff

Three‐dimensional numerical modeling is applied to magnetotelluric principal axis and tipper analysis. Calculations of the impedance, rotation angles, and tipper azimuths are made at the surface of a conducting half‐space which contains perturbed two‐dimensional models. The object is to determine which of the directions is less disturbed by the perturbations, and hence is the more reliable guide to probable strike direction. The results indicate that the principal axis direction is a marginally more stable indicator of strike direction than is the tipper azimuth.


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