Showing papers by "Bei Peng published in 2013"
TL;DR: Observations of five groups of proof mass blocks of accelerometers suggest that the theoretical model is effective in determining the buckling value of a fabricated structure.
Abstract: Microstructure curvature, or buckling, is observed in the micromachining of silicon sensors because of the doping of impurities for realizing certain electrical and mechanical processes. This behavior can be a key source of error in inertial sensors. Therefore, identifying the factors that influence the buckling value is important in designing MEMS devices. In this study, the curvature in the proof mass of an accelerometer is modeled as a multilayered solid model. Modeling is performed according to the characteristics of the solid diffusion mechanism in the bulk-dissolved wafer process (BDWP) based on the self-stopped etch technique. Moreover, the proposed multilayered solid model is established as an equivalent composite structure formed by a group of thin layers that are glued together. Each layer has a different Young's modulus value and each undergoes different volume shrinkage strain owing to boron doping in silicon. Observations of five groups of proof mass blocks of accelerometers suggest that the theoretical model is effective in determining the buckling value of a fabricated structure.
12 citations
03 Apr 2013
TL;DR: The study indicates that reduction in both thermal resistance and pressure drop can be achieved by optimizing the channel configuration and the inlet velocity.
Abstract: This paper presents an approach for modeling and optimization of the channel geometry of a serpentine channel heat sink using multi-objective genetic algorithm. A simple thermal resistance network model was developed to investigate the overall thermal performance of the serpentine channel heat sink. Based on a number of simulations, bend loss coefficient correlation for 1000
3 citations
TL;DR: In this article, a modified least-squares method was proposed to compute the shear strain field in a non-square geometry, where the width-to-height ratio of pixels is not 1.
Abstract: Digital image correlation is widely used in non-contact displacement/strain measurements for numerous engineering applications. Under rigid body rotation or shear deformation, however, the calculated surface strain of specimens is unreliable when camera pixels are characterized by non-square geometry, that is, the width-to-height ratio of pixels is not 1. This study analyzes the computational errors introduced by cameras, and proposes a modified least-squares method that eliminates such errors when the strain field is calculated. Experimental results confirm that the algorithm validly and effectively computes shear strain.
2 citations
TL;DR: In this paper, the influence of dimension and temperature on a MEMS-based capacitive humidity sensor is investigated and a curve showing good linearity and presenting the relationship between capacitance and relative humidity is obtained.
Abstract: The influence of dimension and temperature on a MEMS-based capacitive humidity sensor is researched in this paper. Looyenga’s equation and Dubinin’s semi-empirical data are used to describe the change of dielectric constant of sensing film when absorbing or desorbing water. For these equations and data, a picture of the relationship between dielectric constant and temperature, relative humidity is presented. In the basis of this theory, a simulation is finished, a curve showing good linearity and presenting the relationship between capacitance and relative humidity is obtained. A graph showing the influence of temperature on capacitance at different %RH is given, which considers the change of dielectric constant of Looyenga’s equation and Dubinin’s semi-empirical data only. the result shows that the capacitance decreases with the increasing of temperature. Influence of sensing layer thickness on sensitivity is presented. It shows that when the thickness of sensing layer is about 0.6 micron, the model of humidity sensor has the highest sensitivity.
TL;DR: In this article, an analytical model based on the basis finite element analysis is presented to solve the nonlinear behavior of double-cantilever structure, where the structure beam is replaced with a series of beam elements by traditional finite element method, and pull-in behavior is identified when the convergence of the deflection iteration cannot be achieved after voltage increment.
Abstract: This paper presents an analytical model based on the basis finite element analysis to solve the nonlinear behavior of double-cantilever structure. The structure beam is replaced with a series of beam elements by traditional finite element method. The deformation curve of the beam is calculated by gradually loading voltage in small increments, and pull-in behavior is identified when the convergence of the deflection iteration cannot be achieved after voltage increment. This method considers the effect of deformation on stiffness by establishing a new equivalent stiffness matrix for each voltage step on the basis of the results of previous steps. Through this approach, we prevent the approximate errors of the stiffness matrix from accumulating. The analytical results show good agreement with those obtained by using multiphysics coupling software.