Research Article
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J Appl Mech Eng, Vol. 8 Iss. 1 No: 317
OPEN ACCESS Freely available online
Journal of
Applied Mechanical Engineering
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ISSN: 2168-9873
Multi-Conceptual Mechanical Design Optimization of Capacitive Pressure
Sensors via Finite Element Analysis with use of Anisotropic Behavior of
Silicon <111> Crystal: Summary of Design Optimization Approaches
Amir Javidinejad*
Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Arlington, USA
ABSTRACT
In the world of micro-mechanical design of micro-sensors, up to date, there has not been substantial considerations
given to the actual mechanical or structural aspect of the designs. Hence, most of the currently available designs are
challenged to linearize the “non-linear” sensor’s output by utilization of electronic circuitry. In this research work,
a micro-pressure diaphragm which possess linear pressure-deflection behaviour is designed via FEM optimization
techniques. The diaphragm is modelled as a Silicon (111) plane, which possess plane isotropic properties. A circular
centre boss section is added to the diaphragm and optimization is carried out, to achieve an optimum diaphragm
geometry that would allow for flat or rigid deflection of this boss section under the applied surface pressure loading.
The approximate closed-form deflection solutions are developed using the anisotropic thin plate theory and the
diaphragm deflection behaviour of the FEM optimized design is compared with this thin plate theory model. This
diaphragm design is proposed to be used as the top electrode plate of a capacitive pressure sensor, where linear
pressure-capacitance change behaviour would become present. This pressure diaphragm has a pressure range of 0 to
206843 Pa (30 psi) with a pressure resolution of 689.5 Pa (0.1 psi).
Keywords: Micro-mechanical; Pressure; Technology
INTRODUCTION
Ever since the years 1979-1980, when NASA Langley Space Centre
conducted the first experiments with embedded optical sensors for
strain measurements in low temperature composites, there have
been rapid advancements in the field of “smart” structures. The
U.S. National Science Foundation among other government and
non-government agencies have been sponsoring research projects
for development of cost-effective technologies for remote queried
sensors for health and usage monitoring of composite structures.
The sensing and inspection technology systems for composites to
monitor manufacturing processes, assess and non-destructively
evaluate structural integrity, passively monitor the external
environment, internally asses onboard and structural emissions
and provide situational awareness; are important in defence as well
as commercial applications.
The need for development of such monitoring systems has risen
from the fact that mounted instrumentation adds undesirable
external mass which can adversely affect the static and dynamics
responses of the parent composite structures. Furthermore,
extensively wired sensory systems, for structural health and usage
monitoring of the structures, has some drawbacks which include,
increasing structural weight and reduction of structural integrity,
possible structural intractability due to damage to embedded
interconnects and the unfeasibility of structural reparability. All
of which lead to an increased need for utilization of micro smart
structures and consequently leading to the need for utilization of
micro embeddable sensing systems.
The NSF research at The University of Texas at Arlington is an
effort to develop cost effective technology for remotely queried
sensory units in a composite structure [1]. It is essential to integrate
research effort among the three areas of thin film antennas,
electronic circuits and mechanics. This program’s goal has been
to develop cost effective technology for remotely queried sensory
units in a composite structure with the objective to design and
develop micro thin-film antennas which are compatible with
composite manufacturing procedures, low power transponder,
query protocols, power acquisition and utilization by sensory units,
micromechanics of sensing and actuation of closely placed micro-
scale sensors and actuators, manufacturing issues and the optimal
placement of sensory clusters [2].
This research primarily has addressed structural monitoring at the
Correspondence to: Javidinejad A, Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Arlington, USA,
Tel: 817-272-2011; E-mail: Amir.Javidinejad@gmail.com
Received: January 12, 2019, Accepted: February 05, 2019, Published: February 14, 2019
Citation: Javidinejad A (2019) Multi-Conceptual Mechanical Design Optimization of Capacitive Pressure Sensors via Finite Element Analysis with
use of Anisotropic Behavior of Silicon <111> Crystal: Summary of Design Optimization Approaches. J Appl Mech Eng, 8:317. doi: 10.35248/2168-
9873.19.8.317
Copyright: © 2019 Javidinejad A. This is an open access article distributed under the term of the Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.