Mechanical Engineering ETDs

Khawar Abbas

Publication Date

1-29-2009

Abstract

Many MEMS devices utilize thin metallic films as mechanical structures. The elastic and plastic properties of these thin films (thickness < 1μm) are significantly different from those of the bulk material. At these scales the volume fraction of material defects such as: grain boundaries, dislocations and interstitials become quite significant and become a chief contributor the physical and mechanical material properties of the thin films. Aluminum (Al), Copper (Cu), Nickel (Ni) and Gold (Au) are popular thin film materials used in MEMS/NEMS. Various studies have been conducted in recent years to study the mechanical properties of freestanding thin films in situ in TEM to study their failure mechanisms. Some of these studies utilize MEMS devices as actuators. These actuators are often co-fabricated with the specimen being tested therefore limiting the type of specimen that could be tested. Also these MEMS actuators are almost never traceably calibrated and their response is calculated. This thesis describes the design and fabrication process of a MEMS actuator for materials testing in-situ in TEM. The actuator is fabricated independent of the specimen. A setup was designed to calibrate these devices with a method that can be traced back to NIST standards. It has been shown that the calibrated response of these MEMS actuators is different from its calculated response and the use of un-calibrated devices for materials testing can lead to misleading results.

Keywords

Microactuators--Design and construction, Microactuators--Calibration, Metallic films--Mechanical properties--Testing, Microelectromechanical systems--Materials--Testing.

Degree Name

Mechanical Engineering

Level of Degree

Masters

Department Name

Mechanical Engineering

First Committee Member (Chair)

Shen, Yu-Lin

Second Committee Member

Al- Haik, Marwan

Document Type

Thesis

Language

English

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