Capacitive silicon accelerometer with highly symmetrical design

AbstractEffects of finite source material, in multilevel interconnect systems, on reliability has been investigated. Two types of novel test structures were used in this study: 1] asymmetrical design structure in width and thickness for the top and bottom conductor layers, 2] symmetrical design structure in width and thickness for the top and bottom conductor layers. The results of the asymmetric contact and via chains studies showed that the electromigration lifetimes were not effected by the difference in the magnitude of the finite source material. The electromigration lifetimes of the symmetrical via structure, in width and thickness for the top and bottom conductor layers, exhibited a strong dependence on the finite source material. A failure model is proposed to explain the effect of finite source material on electromigration performance in such interconnect systems.

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Effect of Tibial Component Alignment and Posterior Slope on Tibial Coverage in a Chinese Population: A Three-dimensional Anthropometric Study

The Journal of Knee Surgery ◽

10.1055/s-0038-1676564 ◽

2018 ◽

Vol 33 (01) ◽

pp. 053-061 ◽

Cited By ~ 1

Author(s):

Long Shao ◽

Ting Wang ◽

Junyi Liao ◽

Wei Xu ◽

Xi Liang ◽

...

Keyword(s):

Tibial Component ◽

Three Dimensional ◽

Prosthesis Design ◽

Tibial Tubercle ◽

Virtual Surgery ◽

Component Alignment ◽

Posterior Slope ◽

Symmetrical Design ◽

Tibial Component Alignment ◽

Significant Difference

AbstractThe standard for rotational alignment and posterior slope of the tibial component in total knee arthroplasty remains controversial. This study aimed to evaluate the effect of tibial component alignment and posterior slope on tibial coverage. Computer tomographic scans of 101 tibial specimens were used to reconstruct three-dimensional tibia models. A virtual surgery was performed to generate a resection plane with different posterior slopes on the proximal tibia. Symmetrical and anatomical tibial components were placed aligning to the medial one-third of tibial tubercle (Insall) and the medial edge of patella tendon (Akagi), respectively. Differences in coverage and mismatch were evaluated and statistically compared across alignments, slope angles, and genders. The tibial coverage increased from 83.21 to 85.96% for Akagi's alignments and from 85.19 to 87.22% for Insall alignments along with the increasing of posterior slope from 0 to 7 degrees. Regardless of the prosthesis design, there was a significant difference between two rotational alignments as the Insall alignment was significantly higher in tibial coverage. With a slope of 7 degrees, more overhang along with less underhang anteromedially were found in males compared with females. The current anatomical tibial design has a tendency of overhang in the anteromedial zone which does not exist in the symmetrical design. The current tibial baseplate design has better tibial coverage when aligning to the medial third of tibial tuberosity with slopes of 5 and 7 degrees. Gender difference should be taken into account and given priority for prosthesis design.

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A Mirror-Symmetrical XY Compliant Parallel Manipulator With Improved Performances Without Increasing the Footprint

10.1115/detc2021-69032 ◽

2021 ◽

Author(s):

Jiaxiang Zhu ◽

Guangbo Hao ◽

Shiyao Li ◽

Shuwen Yu ◽

Xianwen Kong

Keyword(s):

Mirror Symmetry ◽

Single Layer ◽

Parallel Manipulators ◽

Element Analysis ◽

Input And Output ◽

Symmetrical Design ◽

Out Of Plane ◽

Small Footprint ◽

Free Body ◽

Output Stages

Abstract The design of XY compliant parallel manipulators (CPMs) remains challenging considering the tradeoff between the mirror-symmetry for better constrained undesired rotations and the small footprint, although a significant number of XY CPMs have been reported in extensive applications. This paper presents a new XY CPM using mirror-symmetry without increasing its footprint, mainly aiming to reduce the undesired parasitic rotations of input and output motion stages. The concept of higher degree of stiffness centre symmetry is deployed to tackle the parasitic rotations, leading to a multi-layer compact XY CPM design with each layer being a rotation-symmetrical design. A nonlinear and analytical model of the proposed XY CPM is derived using free body diagrams and the Beam Constrained Model (BCM) to accurately analyse its performance characteristics over a large range of motion. The designed XY CPM is then verified by the nonlinear finite element analysis (FEA) method. Finally, the proposed multi-layer design is comprehensively compared with the well-received single-layer rotation-symmetrical design. It is shown in the new design that the parasitic rotations of input and output stages along with the actuator isolation are significantly reduced and that the out-of-plane-stiffness is also significantly increased.

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