Austin, Texas
June 14, 2009
June 14, 2009
June 17, 2009
2153-5965
Mechanical Engineering
10
14.795.1 - 14.795.10
10.18260/1-2--5599
https://strategy.asee.org/5599
337
AC 2009-1885
INTRODUCING "MEMS" TO UNDERGRADUATE "ME" STUDENTS Introduction In the past ten years, both industry and research groups have made significant advances in Micro Electro Mechanical Systems (MEMS). These highly promising models and systems have potential for applications in many areas including Mechanical, Electrical and Medical industries. Although MEMS has been introduced for over a decade, many engineering students are unaware of its existence and its associated possibilities in the research, development, and application areas. This paper provides two practical and interesting examples of applications of -Stage Accelerometer for Automobile of a Micro- MEMS Circuit when a change in temperature of occurs. These projects have been designed for sophomore level students. Pedagogical measures have been taken for their realistic effectiveness (nation-wide). Therefore, the framework of the projects has been set at a level that sophomores may succeed in understanding them and developing interest in MEMS. Their imagination will also be challenged. A higher level of details is provided for the first project to serve as a sample of the depth and breadth of information that may be added and transmitted to the students.
Project #1: Design of a Two-Stage Accelerometer for Automobile Airbags
Performance requirements An accelerometer that would deploy a Two-Stage Airbag System with the first stage deployed at a G- *g with a Voltage Range of 6 9 volts and the second stage deployed at a G- 12*g with a Voltage R V 12 volts. The spatial constraints limit the space to a rectangular prism with the dimensions of 3.0 mm deep, 4.50 mm wide and 6.0 mm long.
Design Characteristics Figure MP-1 illustrates a proposed design for the Two-Stage accelerometer. In this figure, the middle cantilever beam supports a mass (m 1) and the two outside cantilevers form a unified beam by (together) supporting a second mass (m 2). A single sheet of material is utilized to form the two beams (in the shape of an inclusion of the two independently activated units.
General Description of the System With reference to the attached coordinate system (in the figure), the vehicle is moving in the Z- -on collision, the masses m 1 and m- 2 will respectively exert forces equal to F1 = m1 . a1 and F2 = m2 . a2 on their associated beams. These forces will generate new levels of stress and strain on the beams. Piezoelectric sensors are implanted at the roots of the beams. Since these sensors are an integral part of the beams, they would experience the same levels of stress / strain. At a certain level of deformation, they will generate the necessary level of voltage to activate the switch(es) for deploying the airbag(s).
Proceedings of the 2009 American Society for Engineering Education Annual Conference & Exposition Copyright © 2009, American Society for Engineering Education
Sepahpour, B. (2009, June), Introducing "Mems" To Undergraduate Me Students Paper presented at 2009 Annual Conference & Exposition, Austin, Texas. 10.18260/1-2--5599
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