# Power Optimization Configurations in Piezoelectric Energy

## Transcript Of Power Optimization Configurations in Piezoelectric Energy

Power Optimization Configurations in Piezoelectric Energy Harvesting Systems

by Kristen Thompson Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Engineering

in the Electrical Engineering

Program

YOUNGSTOWN STATE UNIVERSITY December 2020

Power Optimization Configurations in Piezoelectric Energy Harvesting Systems Kristen Thompson

I hereby release this thesis to the public. I understand that this thesis will be made available from the OhioLINK ETD Center and the Maag Library Circulation Desk for public access. I also authorize the University or other individuals to make copies of this thesis as needed for scholarly research.

Signature:

Kristen Thompson, Student

Date

Approvals:

Frank X Li, Thesis Advisor

Date

Mike Ekoniak, Committee Member

Date

Eric MacDonald, Committee Member

Date

Dr. Salvatore A. Sanders, Dean of Graduate Studies

Date

ABSTRACT Energy harvesting research from vibration gained great interest for its potential to excel in lower power applications. Often piezoelectric devices are implemented and harness the vibrational frequency as a means to excite the component. The piezoelectric device converts mechanical strain into electrical charge and exists in various prototypes. The cantilevered beam and performance are dependent on the material configuration, size, shape, and layers. This thesis analyzes several piezoelectric components to determine the best way for power optimization and efficiency in this conversion. Store purchased piezoelectric components were soldered and assembled electrically in series or parallel. To increase energy harvesting efficiency at different frequencies, which exist primarily from an ambient source, the output prototype was analyzed.

iii

Table of Contents

Abstract .............................................................................................................................. iii List of Figures ......................................................................................................................v List of Terms...................................................................................................................... vi Acknowledgements .......................................................................................................... vii

CHAPTER 1 RESEARCH AREAS FOR PIEZOELECTRIC COMPONENTS 1.1 Project Objectives ........................................................................................................1 1.2 Research Question .......................................................................................................2 1.3 Thesis Overview ..........................................................................................................3

CHAPTER 2 ENERGY HARVESTING 2.1 Introduction..................................................................................................................5 2.2 Electrostatic Energy Harvester ....................................................................................6 2.3 Electromagnetic Energy Harvester ..............................................................................6 2.4 Applications of Energy Harvesting..............................................................................7

CHAPTER 3 PIEZOELECTRICITY LITERATURE REVIEW 3.1 Piezoelectric Effect ...................................................................................................12

3.1.1 Direct vs Indirect Piezoelectric Effect .........................................................13 3.2 Piezoelectric Constitutive Equations .........................................................................14

3.2.1 Vibration ......................................................................................................17 3.3 Fundamental Modes of Operation .............................................................................19

3.3.1 Charge Constant ...........................................................................................19 3.3.2 Voltage Constant...........................................................................................21 3.3.3 Electromechanical Coupling Factor k...........................................................22 3.4 Configuration of Piezoelectric Energy Harvesters ....................................................23 3.5 Film & Materials Configuration ................................................................................25 3.5.1 Single Crystals ..............................................................................................25 3.5.2 Polymers .......................................................................................................26 3.5.3 Ceramic Materials .........................................................................................26 3.6 Piezoelectric Energy Conversion Efficiency .............................................................28

CHAPTER 4 METHODOLOGY 4.1 Initial Investigations...................................................................................................31

4.1.2 Piezoelectric Elements ..................................................................................33 4.1.3 LED Verification ..........................................................................................35 4.2 Experimental Setup ....................................................................................................38 4.3 Results........................................................................................................................45

CHAPTER 5 CONCLUSION 5.1 Final Remarks ............................................................................................................46

Bibliography .....................................................................................................................49

iv

List of Figures

Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

1: Block Diagram of Energy Harvesting Hierarchy 2: Flow of ions in a rechargeable battery 3: Direct Polarization 4: Indirect Polarization 5: (a) Before poling (b) In poling (c) After polarization 6: Frequency response with respect to changing impedance 7: Modes of Operation 8: Axis Direction 9: Piezoelectric Configurations a.) Unimorph b.) Bimorph 10: Block diagram of an energy harvesting application 11: Electrical Schematic of the Energy Harvesting Diagram 12: Piezoelectric Components 13: Piezoelectric device S118-J1SS-1808YB 14: Equivalent circuit of a piezoelectric element 15: LED Test 16: Illustration of experimental setup 17: Block Diagram of setup 18: Piezoelectric configurations for (a) Series and (b) Parallel connections 19: Illustration of the second experiment 20: Block Diagram of experiment 2 21: Output Voltage Response vs Load Resistance (Parallel Configuration) 22: Output Voltage Response vs Load Resistance (Series Configuration) 23: Output Power vs Resistance Load (Parallel Configuration) 24: Output Power vs Resistance Load (Series Configuration)

Table

Table 1: Coupling Factor Equations Table 2: Report of Piezoelectric Materials & Applications Table 3: Piezoelectric Voltage Output Table 4: LCR Measurements for the inductance, capacitance, resistance, and impedance

v

List of terms

A – Area of plate

D – Charge Density Displacement

D – Electric Flux Density 𝑑 – displacement of parallel plate capacitors 𝑑𝑖𝑗 – Charge constant

E – Electric Field 𝜀 – Permittivity 𝜀𝑜 – Permittivity of free space 𝑓𝑎 – Anti-Resonance Frequency 𝑓𝑚 – Minimum impedance Frequency 𝑓𝑛 – Maximum impedance 𝑓𝑜 – Resonant frequency of cantilever (without 𝑓𝑟 – Resonance Frequency (min impedance) 𝑓𝑠 – Resonance Frequency (max impedance) 𝑔𝑖𝑗 – Voltage constant

𝑘𝑖𝑗 – Coupling Factor

𝑘𝑇 – Stiffness of Piezoelectric 𝑚𝑒𝑓𝑓 – Mass of the device

Q – Charge

S – Strain

T - Material Stress

V- Voltage

load)

vi

Acknowledgement I want to extend a sincere thank you to all of those that have helped me in my academic journey at Youngstown State. To my supervisor, Dr. Frank Li, for his guidance throughout my graduate studies. I would like to acknowledge both committee members Dr. Eric MacDonald, and Dr. Mike Ekoniak for their continued support throughout this process. To my work colleagues at Goodyear, your expertise throughout my internship was invaluable. You all taught me the importance of continuous education and your insightful feedback allowed me to be where I am today. To my parents, for your continued love and support that you have always given me. Thank you for your unwavering support and continuous encouragement throughout my years of study. I could not have completed this without the support of my friends, Jess, Nadine, and Marina for their distractions to ease my mind outside of research. I appreciate you ladies and am so thankful for our friendship.

vii

Chapter 1 Research Areas

1.1 Project Objectives The opportunity for the research presented studies the power output performance

and energy conversion efficiency of various piezo elements within a mathematical model. To overcome barriers of inefficient power outputs, many researchers explored ways to maximize efficiency and bandwidth by studying the impacts of different piezo materials, design configurations, and other optimization techniques [13][14][29]. If this were to become more effective in producing a consistent output, it can easily be adapted into as a power source for low power electronic devices. The compression or stretching of the piezoelectric component results in the dipole orientation to align themselves along the axis of the crystal, leads to a net polarization across the surface.

Energy harvesting processes derive this energy and harness it to be used for low power applications. The implications of utilizing renewable energy create a less detrimental impact on the environment and are less harmful in their CO2 emissions. Batteries often need to be replaced, but the duration of time they last depend on the application it is being used for. Advancements in the development of lithium-ion battery technology greatly impacted the automotive industry and production of electric vehicles. There are a wide range of damaging implications as a result of battery production, making energy harvesting an attractive option to reduce energy consumptions [7][11].

Vibration exists in everyday environments and is a viable option to exploit this energy using the piezoelectric effect which converts the mechanical stress to electrical charge.

1

1.2 Research Question The main research in question is accurately characterizing the performance of piezoelectric elements. Low power applications are easily sourced through artificial sources such as vibration. Piezoelectric components exist in a variety of configurations, types of materials, and orientations with respect to the 3D plane that all impact the dipole excitations created from the mechanical strain induced. An EMF, electromagnetic field is applied across the crystal material, producing a voltage across it.

Covid-19 resulted in the mathematical model analysis to compare the piezo element behaviors on an equivalent model. The original concept of this research was to validate and analyze road vibrations as well as tire deformation. This deformation on the piezo element was to be characterized and tested to determine if it was able to power a TPMS system. However, the research question of this thesis deviated due to remote learning with the pandemic. Instead, experimental setups are used to demonstrate this concept in a working model. This study examines the vibrational output relative to the spring mass system based on the frequency of excitation [15]. The magnitude of the frequency varies depending on the environmental setting, and there is interest in exploring ways to harvest wasted energy not captured from those vibrations. There are concerns related to if the energy harvester can effectively generate enough charge under excitations.

Project Objectives: • Predict output of piezoelectric harvester and analyze the influence of design fabrication parameters on performance • Experimental setup notating power optimization techniques of the piezoelectric component.

2

by Kristen Thompson Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Engineering

in the Electrical Engineering

Program

YOUNGSTOWN STATE UNIVERSITY December 2020

Power Optimization Configurations in Piezoelectric Energy Harvesting Systems Kristen Thompson

I hereby release this thesis to the public. I understand that this thesis will be made available from the OhioLINK ETD Center and the Maag Library Circulation Desk for public access. I also authorize the University or other individuals to make copies of this thesis as needed for scholarly research.

Signature:

Kristen Thompson, Student

Date

Approvals:

Frank X Li, Thesis Advisor

Date

Mike Ekoniak, Committee Member

Date

Eric MacDonald, Committee Member

Date

Dr. Salvatore A. Sanders, Dean of Graduate Studies

Date

ABSTRACT Energy harvesting research from vibration gained great interest for its potential to excel in lower power applications. Often piezoelectric devices are implemented and harness the vibrational frequency as a means to excite the component. The piezoelectric device converts mechanical strain into electrical charge and exists in various prototypes. The cantilevered beam and performance are dependent on the material configuration, size, shape, and layers. This thesis analyzes several piezoelectric components to determine the best way for power optimization and efficiency in this conversion. Store purchased piezoelectric components were soldered and assembled electrically in series or parallel. To increase energy harvesting efficiency at different frequencies, which exist primarily from an ambient source, the output prototype was analyzed.

iii

Table of Contents

Abstract .............................................................................................................................. iii List of Figures ......................................................................................................................v List of Terms...................................................................................................................... vi Acknowledgements .......................................................................................................... vii

CHAPTER 1 RESEARCH AREAS FOR PIEZOELECTRIC COMPONENTS 1.1 Project Objectives ........................................................................................................1 1.2 Research Question .......................................................................................................2 1.3 Thesis Overview ..........................................................................................................3

CHAPTER 2 ENERGY HARVESTING 2.1 Introduction..................................................................................................................5 2.2 Electrostatic Energy Harvester ....................................................................................6 2.3 Electromagnetic Energy Harvester ..............................................................................6 2.4 Applications of Energy Harvesting..............................................................................7

CHAPTER 3 PIEZOELECTRICITY LITERATURE REVIEW 3.1 Piezoelectric Effect ...................................................................................................12

3.1.1 Direct vs Indirect Piezoelectric Effect .........................................................13 3.2 Piezoelectric Constitutive Equations .........................................................................14

3.2.1 Vibration ......................................................................................................17 3.3 Fundamental Modes of Operation .............................................................................19

3.3.1 Charge Constant ...........................................................................................19 3.3.2 Voltage Constant...........................................................................................21 3.3.3 Electromechanical Coupling Factor k...........................................................22 3.4 Configuration of Piezoelectric Energy Harvesters ....................................................23 3.5 Film & Materials Configuration ................................................................................25 3.5.1 Single Crystals ..............................................................................................25 3.5.2 Polymers .......................................................................................................26 3.5.3 Ceramic Materials .........................................................................................26 3.6 Piezoelectric Energy Conversion Efficiency .............................................................28

CHAPTER 4 METHODOLOGY 4.1 Initial Investigations...................................................................................................31

4.1.2 Piezoelectric Elements ..................................................................................33 4.1.3 LED Verification ..........................................................................................35 4.2 Experimental Setup ....................................................................................................38 4.3 Results........................................................................................................................45

CHAPTER 5 CONCLUSION 5.1 Final Remarks ............................................................................................................46

Bibliography .....................................................................................................................49

iv

List of Figures

Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

1: Block Diagram of Energy Harvesting Hierarchy 2: Flow of ions in a rechargeable battery 3: Direct Polarization 4: Indirect Polarization 5: (a) Before poling (b) In poling (c) After polarization 6: Frequency response with respect to changing impedance 7: Modes of Operation 8: Axis Direction 9: Piezoelectric Configurations a.) Unimorph b.) Bimorph 10: Block diagram of an energy harvesting application 11: Electrical Schematic of the Energy Harvesting Diagram 12: Piezoelectric Components 13: Piezoelectric device S118-J1SS-1808YB 14: Equivalent circuit of a piezoelectric element 15: LED Test 16: Illustration of experimental setup 17: Block Diagram of setup 18: Piezoelectric configurations for (a) Series and (b) Parallel connections 19: Illustration of the second experiment 20: Block Diagram of experiment 2 21: Output Voltage Response vs Load Resistance (Parallel Configuration) 22: Output Voltage Response vs Load Resistance (Series Configuration) 23: Output Power vs Resistance Load (Parallel Configuration) 24: Output Power vs Resistance Load (Series Configuration)

Table

Table 1: Coupling Factor Equations Table 2: Report of Piezoelectric Materials & Applications Table 3: Piezoelectric Voltage Output Table 4: LCR Measurements for the inductance, capacitance, resistance, and impedance

v

List of terms

A – Area of plate

D – Charge Density Displacement

D – Electric Flux Density 𝑑 – displacement of parallel plate capacitors 𝑑𝑖𝑗 – Charge constant

E – Electric Field 𝜀 – Permittivity 𝜀𝑜 – Permittivity of free space 𝑓𝑎 – Anti-Resonance Frequency 𝑓𝑚 – Minimum impedance Frequency 𝑓𝑛 – Maximum impedance 𝑓𝑜 – Resonant frequency of cantilever (without 𝑓𝑟 – Resonance Frequency (min impedance) 𝑓𝑠 – Resonance Frequency (max impedance) 𝑔𝑖𝑗 – Voltage constant

𝑘𝑖𝑗 – Coupling Factor

𝑘𝑇 – Stiffness of Piezoelectric 𝑚𝑒𝑓𝑓 – Mass of the device

Q – Charge

S – Strain

T - Material Stress

V- Voltage

load)

vi

Acknowledgement I want to extend a sincere thank you to all of those that have helped me in my academic journey at Youngstown State. To my supervisor, Dr. Frank Li, for his guidance throughout my graduate studies. I would like to acknowledge both committee members Dr. Eric MacDonald, and Dr. Mike Ekoniak for their continued support throughout this process. To my work colleagues at Goodyear, your expertise throughout my internship was invaluable. You all taught me the importance of continuous education and your insightful feedback allowed me to be where I am today. To my parents, for your continued love and support that you have always given me. Thank you for your unwavering support and continuous encouragement throughout my years of study. I could not have completed this without the support of my friends, Jess, Nadine, and Marina for their distractions to ease my mind outside of research. I appreciate you ladies and am so thankful for our friendship.

vii

Chapter 1 Research Areas

1.1 Project Objectives The opportunity for the research presented studies the power output performance

and energy conversion efficiency of various piezo elements within a mathematical model. To overcome barriers of inefficient power outputs, many researchers explored ways to maximize efficiency and bandwidth by studying the impacts of different piezo materials, design configurations, and other optimization techniques [13][14][29]. If this were to become more effective in producing a consistent output, it can easily be adapted into as a power source for low power electronic devices. The compression or stretching of the piezoelectric component results in the dipole orientation to align themselves along the axis of the crystal, leads to a net polarization across the surface.

Energy harvesting processes derive this energy and harness it to be used for low power applications. The implications of utilizing renewable energy create a less detrimental impact on the environment and are less harmful in their CO2 emissions. Batteries often need to be replaced, but the duration of time they last depend on the application it is being used for. Advancements in the development of lithium-ion battery technology greatly impacted the automotive industry and production of electric vehicles. There are a wide range of damaging implications as a result of battery production, making energy harvesting an attractive option to reduce energy consumptions [7][11].

Vibration exists in everyday environments and is a viable option to exploit this energy using the piezoelectric effect which converts the mechanical stress to electrical charge.

1

1.2 Research Question The main research in question is accurately characterizing the performance of piezoelectric elements. Low power applications are easily sourced through artificial sources such as vibration. Piezoelectric components exist in a variety of configurations, types of materials, and orientations with respect to the 3D plane that all impact the dipole excitations created from the mechanical strain induced. An EMF, electromagnetic field is applied across the crystal material, producing a voltage across it.

Covid-19 resulted in the mathematical model analysis to compare the piezo element behaviors on an equivalent model. The original concept of this research was to validate and analyze road vibrations as well as tire deformation. This deformation on the piezo element was to be characterized and tested to determine if it was able to power a TPMS system. However, the research question of this thesis deviated due to remote learning with the pandemic. Instead, experimental setups are used to demonstrate this concept in a working model. This study examines the vibrational output relative to the spring mass system based on the frequency of excitation [15]. The magnitude of the frequency varies depending on the environmental setting, and there is interest in exploring ways to harvest wasted energy not captured from those vibrations. There are concerns related to if the energy harvester can effectively generate enough charge under excitations.

Project Objectives: • Predict output of piezoelectric harvester and analyze the influence of design fabrication parameters on performance • Experimental setup notating power optimization techniques of the piezoelectric component.

2