Measurement of Deformation of a Multilayer Piezoelectric Actuator

Title page

MEASUREMENT OF DEFORMATION OF A MULTILAYER PIEZOELECTRIC ACTUATOR

SCHOOL OF MECHANICAL AND AEROSPACE ENGINEERING

A final year project report

presented to the

Nanyang Technological University

in partial fulfilment of the

requirements for the

Degree of Bachelor of Engineering (Mechanical Engineering)

Nanyang Technological University

Year (2007)

Abstract

Piezoelectric (PZT) materials are used to convert electrical energy to mechanical energy and vice-versa. The precise motion that results when an electric potential is applied to a piezoelectric material is of primordial importance for nano-positioning.

This experiment covers the measurements and fatigue testing of PZT cantilever beams. The PZT is easily excited with a low voltage which gives rise to minute defections.

The PZT was then subjected to various fatigue parameters to determine the breaking point and the different types of fatigue reactions of the PZT.

It was clearly seen that fatigue plays a big part in the performance of the PZT. The parameter that played a major role in fatigue damage was temperature. High temperatures were seen to degrade deflections up to 40%.

TABLE OF CONTENTS

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TITLE PAGEвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦...вЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.вЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.ii

ABSTRACTвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦..iii

ACKNOWLEDGMENTSвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.вЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦iv

TABLE OF CONTENTSвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.вЂ¦Ð²Ð‚¦..v

LIST OF FIGURESвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦...…vi

CHAPTER 1: INTRODUCTIONвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.вЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.........1

1.1 BackgroundвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦...вЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦..1

1.2 ScopeвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦...вЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦5

CHAPTER 2: BACKGROUNDвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.вЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦6

CHAPTER 3: EXPERIMENTAL SETUPвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.8

CHAPTER 4: RESULTS AND DISCUSSIONвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦...13

CHAPTER 5: CONCLUSIONвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.42

REFERENCESвЂ¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦Ð²Ð‚¦.43

APPENDIX

List of Figures

Figure 1.1: Schematic of a coated piezoelectric cantilever in use as a biological sensor

Figure 1.2: Some piezoelectric actuators available.

Figure 1.3: Some piezoelectric parts.

Figure 2.1: The atomic structure of PZT

Figure 2.2: (left to right) Before poling, After Poling and During excitation

Figure 3.1: Setup A

Figure 3.2: Setup B

Figure 3.3: Computer terminal (left) and scan head camera (inset)

Figure 3.4: Setup A and B

Figure 3.5: The function generator, power amplifier and oscilloscope

Figure 3.6: Old Experimental Setup

Figure 3.7: New Experimental Setup

Figure 4.1: Background displacement

Figure 4.2: Background velocity

Figure 4.3: Frequency set at 150Hz

Figure 4.4: Frequency set at 950Hz

Figure 4.5: Reference without excitation, setup A

Figure 4.6: Reference without excitation, setup B

Figure