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A Study of Curved Flexures for MEMS

Minhee Jun[1], and Jason V. Clark[1]
[1]Departments of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA

Large deflection actuators are becoming increasingly important for microsystems. Since actuation forces are usually small, large deflection actuators usually require flexures with low stiffness. Rectangular serpentine flexures are often used for such actuators due to their low stiffness and large linear deflection range. In this paper we investigate the performance of curved serpentine flexures ...

Effects of the Film Thickness on the Transient Conjugate Opticalthermal Fields in Thin Films Irradiated by Moving Sources in Back and Front Treatments

N. Bianco[1], O. Manca[2], S.Nardini[2], and D. Ricci[2]

[1]DETEC, Università degli Studi di Napoli Federico II, Napoli, Italy
[2]DIAM, Seconda Università degli Studi di Napoli, Aversa, CE, Italy

A two dimensional transient analysis of the conjugate optical-thermal fields induced in a multilayer thin film structure by a moving Gaussian laser source is carried out numerically in order to compare back and front laser treatment processes. Thermal and optical nonlinearity is induced during transient heating, since the response of weakly absorbing thin films depends on temperature. The heat ...

Modeling Soil Water Dynamics with Time-Variable Soil Hydraulic Properties

A. Schwen[1], G. Bodner[2], A. Schnepf[3], D. Leitner[3], G. Kammerer[1], and W. Loiskandl[1]

[1]Institute of Hydraulics and Rural Water Management, Univ. Natural Resour. Appl. Life Sci., BOKU, Wien, Austria
[2]Institute of Agronomy and Plant Breeding, Univ. Natural Resour. Appl. Life Sci., BOKU, Wien, Austria
[3]Institute of Soil Science, Univ. Natural Resour. Appl. Life Sci., BOKU, Wien, Austria

Modeling soil water dynamics requires an accurate description of soil hydraulic properties, i.e. the retention and hydraulic conductivity functions. Generally, these functions are assumed to be unchanged over time in most simulation studies. In this paper, we implemented temporal changes in the soil hydraulic properties in a Richards’ equation simulation of soil water dynamics. Based on ...

Multiphysics Model of the NovaSure Endometrial Ablation Procedure

G.T. Martin[1], and L. Angelone[2]
[1]Hologic, Inc., Bedford, Massachusetts, USA
[2]Massachusetts General Hospital, Harvard Medical School, Marlborough, Massachusetts, USA

The NovaSure Endometrial Ablation System® is designed to remove the endometrial lining in the uterine cavity of women who suffer from menorrhagia. The NovaSure disposable device consists of a 2-pole, 4 electrode array that is inserted into the uterine cavity and deployed. We have developed a COMSOL Multiphysics model of the NovaSure ablation process. The model utilized COMSOL Multiphysics ...

Wall Effects in Convective Heat Transfer from a Sphere to Power Law Fluids in Tubes

D. Song[1], R. Gupta[1], and Chhabra[2]

[1]West Virginia University, Morgantown, West Virginia, USA
[2]Indian Institute of Technology, Kanpur, India

Heat transfer from a sphere having a uniform temperature and falling axially in a cylindrical tube filled with an incompressible power-law liquid is numerically investigated. The governing equations for simultaneous flow around a confined sphere and heat transfer to power-law fluids were solved numerically using COMSOL Multiphysics. It was found that the wall effects on the mean Nusselt number ...

Rechargeable Battery for Hybrid Diesel-Electric Locomotive

Michael A. Vallance
Team Leader, GE Global Research

Over time, rechargeable batteries degrade and eventually stop working. You see some combination of declining capacity, rapid self-discharge, and reduced power. Degradation mode depends on battery design, but also on the application. Often, multiple physical processes contribute to degradation. In the laboratory, you can measure performance degradation. You can dissect the battery to discover ...

Quasi-static Analysis on the Effect of Metal Penetrating Depth into the Substrate in Microstriplines

S. Musa, and M. Sadiku
Prairie View A&M University Networking Academy (PVNA), Prairie View, TX, USA

The effect of metallization thickness on planar transmission lines plays an essential role in microwave integrated circuits and thin film technology, especially in the propagation characterization and the electric field distribution in the structures. The objective of this paper is to consider the planar transmission lines with finite thickness not penetrating and penetrating into isotropic ...

Sound Attenuation by Hearing Aid Earmold Tubing

M. Herring Jensen
Widex A/S, Vaerloese, Denmark

In this study we model the sound attenuation properties of a hearing aid earmold tube. The model includes thermoviscous acoustic effects and it couples structural vibrations to the external acoustic field. Moreover, the finite element domain is coupled at two boundaries with an electroacoustic model of a hearing aid and an acoustic 2-cc coupler.

Designing the Actuator for the Next-Generation Astronomical Deformable Mirrors: a Multidisciplinary and Multiphysics Approach

C. Del Vecchio[1], R. Biasi[2] , D. Gallieni[3], and A. Riccardi[1]

[1]INAF-OAA, Fierenze, Italy
[2]Microgate Srl, Bolzano, Italy
[3]ADS International Srl, Valmadrera, Italy

The actuation system of the deformable mirror is one of the crucial components of an Adaptive Optics unit. One possible implementation comprehends a linear force motor and a capacitive sensor providing the feedback measure signal. Choosing a magnetic circuit that makes optimum use of the magnetic force delivered by a current and properly arranging the electrostatic geometry allows to obtain very ...

Design and Optimization of an All Optically Driven Phase Correction MEMS Deformable Mirror Device using Finite Element Analysis

V. Mathur[1], K. Anglin[1], V.S. Prasher[1], K. Termkoa[1], S.R. Vangala[1], X. Qian[1], J. Sherwood[1], W.D. Goodhue[1], B. Haji-Saeed[2], and J. Khoury[2]

[1]Photonics Center, University of Massachusetts-Lowell, Lowell, Massachusetts, USA
[2]Air Force Research Laboratory/Sensors Directorate, Hanscom Air Force Base, Massachusetts, USA

Optically addressable MEMS mirrors are required for future high density adaptive optics array systems. We have demonstrated a novel technique of achieving this by actuating low stress Silicon Nitride micro mirrors via cascaded wafer bonded Gallium Arsenide photo detectors on Gallium Phosphide. In the work reported here, we discuss the key design parameters of the device, and present the finite ...