View
407
Download
2
Category
Preview:
Citation preview
MSc in Mechatronic Design, Master Thesis:
Energy Harvesting using Carbon Nanotubes Javier Latasa Martínez de IrujoPromotor pracy:
Prof. dr hab. inż. T. Uhl
AGH University of Science and TechnologyFaculty of Mechanical Engineering and Robotics
2
Agenda/ContentsIntroduction
Scope of the ThesisTheoretical Background
Carbon Nanotubes, Properties and Applications Polymer Nanocomposites Energy Harvesting
Nanogenerator Design, Model, Construction and Results Assumptions Proposed Design Nanocomposite Generator Numerical Model Conductive Nanocomposite and
Nanocomposite Generator Construction,Testing and Results
Conclusions Conclusions and Perspectives Future Work
ReferencesFaculty of Mechanical Engineering and Robotics
3
Scope of the Thesis The goal is to design, model and test an energy
harvesting device that takes advantage of carbon nanotubes unique properties.
Special attention given to CNT nanocomposites because of:
• electrical and mechanical properties• accessibility in macroscopic scale
Faculty of Mechanical Engineering and Robotics
Microscope enlarged view showing carbon nanotubes in detail [9]
Publications on CNT composites divided by material type [37]
4
Introduction
Faculty of Mechanical Engineering and Robotics
Fascinating subject of research due to their remarkable mechanical, chemical, and electronic properties.
They are constructions of rolled graphene sheets. CNTs are the strongest and the most flexible
known molecular material due to the unique C–C covalent bonding and seamless hexagonal network.
Single Wall Carbon Nanotubes (SWNT) and Multiwalled Carbon Nanotubes (MWNT) can be found.
a) Graphene sheet, b) Single nanotube, c) Multiwalled nanotube [7]
Carbon Nanotubes
TEM image of a SWCNT bundle [2]
5
Faculty of Mechanical Engineering and Robotics
CNTs Properties
Vectors defining the nanotube structure [8]
Properties overview: Young’s modulus extremely high: 1 TPa [7].
Metalic or semi-conducting depending on their structure (MWNTs always metallic) [3].
Superconductivity at low temperatures [4].
High thermal conductivity in axial direction [3].
CNT in nanocomposites can provide structural and functional capabilities simultaneously [7].
Different chirality CNT with different conducting properties [3]
6
Faculty of Mechanical Engineering and Robotics
Rotational actuator using MWNT as axle for the rotor. Top a) represents concept, b) picture from SEM [48]
CNTs Applications Individual CNTs
• Field emission-based devices• Microscope probes • Chemical and bio sensors• Field effect transistor• Supercapacitors• Nano electronic interconnection• Nano-tools, nano-devices, nano-systems
(NEMS)
Bulk CNT (Nanocomposites)• Reinforce composites strength• Conducting network depending on CNTs
concentration• Piezoeresitivity proportional to strain
Possible future applications include actuation, sensing and generating power; developing actuators capable of high stress and high strain operating at low voltage; multi-functional electrochemical and mechanical sensors [7]
Prototype of CNT layer as FED, Samsung [3]
SEM image of MWNT mounted onto a regular ceramic tip as
probe for atomic force microscopy [44]
7PolymerNanocomposites with CNTs
Faculty of Mechanical Engineering and Robotics
Distribution of micro- and nano-scale fillers of the same 0.1 vol.% in a reference volume of 1 mm3:
A) Al2O3 particle; B) carbon fiber; C) GNP, graphite nanoplatelets; D) CNT [19]
A network within the composite is created. Electrical conductivity. Reinforcement.
Low concentration of CNT needed due to high aspect ratio. Properties depend on
CNTs dispersion. aspect ratio and orientation.
8
Faculty of Mechanical Engineering and Robotics
Depends on the concentration of CNTs (percolation phenomenon) Dispersion plays important role (bundles formation)
General trend of electrical conductivity of CNT
polymer composites [17]
Scheme of percolation phenomenon and conducting
network in conducting composites [19]
Polymer Nanocomposites with CNTs,
Electrical Conductivity:
9
Faculty of Mechanical Engineering and Robotics
Energy Harvesting
Possible energy sources and applications for energy harvesting devices [26]
10
Piezoelectric effect
Faculty of Mechanical Engineering and Robotics
Block diagram for a classic energy-harvesting system [28]
Energy Harvesting from Vibrations
Reaction of a poled piezoelectric element to applied stimuli [33]
11
Energy harvesting devices with this characteristics are found in the literature [36-40].
Faculty of Mechanical Engineering and Robotics
The electrons generated by mechanical stress flow to the top electrode through the circuit, due to the negative piezopotential on the bottom. In the
unbending state, the accumulated electrons flow back to the bottom electrode [39]
Assumptions
Expected voltage in the NCG electrodes for open circuit configuration [40]
12
Proposed Design
Faculty of Mechanical Engineering and Robotics
Based on previous research [36-40], a flexible Nanocomposite Generator (NCG) using Carbon Nanotubes is investigated, adapted and recreated with our means.• The NCG has as central layer a Piezoelectric Nanocomposite (p-NC).• The p-NC consists of CNTs and Piezoelectric powder as fillers within a PDMS (elastomer
polymer) matrix.• Two PDMS layers sandwich the p-NC to reduce high voltage picks.• A PET layers with a conducting ITO coating is used as bottom electrode.• Aluminium foil is used as top electrode.The difference in strength and thickness between top and bottom electrodes brings the mechanically neutral region downwards. This allows for a stress distribution with a unique direction along the p-NC cross section, so that the voltages generated by the piezoelectric particles all have the same polarity.
PDMS
Aluminium foil
PDMS + CNT + PZT
PDMS
ITO coated PET
Electrode 1Electrode 2
Mechanically
Neutral Region
Layer distribution of materials in the NCG. The diagram shows the stress distribution along the cross-section when bending the NCG
13
NCG Numerical Model
Faculty of Mechanical Engineering and Robotics
A model of the NCG was created in COMSOL Multiphysiscs to understand the working mechanism and to anticipate the effect of different parameters. A transient simulation reproducing the real experiment was applied to the
model. Results from simulation agreed with results from experiments. A deeper parametric study to identify the role of the CNTs effect could not be
completed successfully. (The abrupt change in certain variables inherent in the systems, was found to be problematic for the software solver).
Displacement detail in bending position
Stress distribution detail caused by bending position
Voltage and current generated in bending position
14Nanocomposite PreparationNanocomposite generator samples were created in the laboratory.
For a range of CNTs concentration:- Between 0 and 4 wt.% of CNTs.
2 procedures with variations: - With solvent.- Without solvent.
Faculty of Mechanical Engineering and Robotics
ITO coated PET (Bottom electrode)
Schematic view of NCG fabrication process [39]
NCG mixed solution during sonication process
15
Conductivity Study
Faculty of Mechanical Engineering and Robotics
Schematic diagram of the Four-Points Probe Method for resistance measurement [58]
Piezoelectric Nanocomposite (p-NC) samples with deposited silver
electrodes prepared for measurement
Nanocomposite conductivity vs. CNTs concentration.Four-Points Probe Method used for resistivity measurements.
Simple formula for thickness less than half the probe spacing (t < s/2). t is the layer thickness in
cm and resistivity is given in [Ω cm] [58]
16
Resistivity Measurements Results:
Faculty of Mechanical Engineering and Robotics
Resistivity measurement using Four Points Probe
MethodMeasured values of conductivity for the Piezoelectric
Nanocomposite
Conductivity Study
17
Nanocomposite Generator Samples Range of samples to analyse several aspects. Output signal measured for periodical bending-unbending
experiment.
Faculty of Mechanical Engineering and Robotics
Picture of NCG sample
NCG sample attached to the measuring device
Nanocomposite Generator Fabrication
Oscilloscope for NCG output meassurement
18
Faculty of Mechanical Engineering and Robotics
Sample 6.4. Only PZT particles
Oscilloscope screen shot of NCG sample 5.1 output. open circuit voltage
Output Measurement Voltage picks appear with opposite polarity
when bending and unbending. 1–2 volts pick to pick generated even
before poling.(Poling process reported to increase output one order of magnitude [36-40]). CNTs added conductivity provides wider
picks. PDMS insulation attenuates high voltage
and increases internal impedance. Too low internal impedance gives lower
output.
NCG Results
Sample 6.5. Only CNTs
Sample 6.2. CNTs +PZT, low conductivity , direct polarity.
Sample 6.2. CNTs +PZT, low conductivity, inverted polarity.
Sample 6.3. CNTs +PZT, high conductivity , no insulation
layer.
Sample 6.1. CNTs +PZT, high conductivity , no insulation
layer.
19
Faculty of Mechanical Engineering and Robotics
Conclusions and PerspectivesPromising results:o Production procedure for p-NC was established and
possible improvements suggested.o Conductivity vs. CNTs Concentration curve obtained.o Flexible NCG was proved to harvest power.
Perspectives:o Possible new applications for the nanocomposite, e.g. as
flexible electrode in a NCG or other device.o Once the NCG is fully developed it could be used as power
supply for wireless sensors, MEMS and other small devices.
Output voltage for one of the NCG samples
Example of wireless distributed sensor network [70]
20
Future Work in this Field
Faculty of Mechanical Engineering and Robotics
There is place for developement in this area.o NCG output optimization (modelling and experimental).
Precise identification of CNT concentration effects. Identification of PDMS insulation layer effects.
o Generated power storage and use. Design an appropriate converting circuit. Find suited energy storage system [30].
o Fabrication procedure for P-NC and NCG improvement.
Converting circuit and resistive impedance matching circuit [35]
Efficiency as function of frequency and resistive output
load in a piezoelectric generator [30]
21
References[1] S. Iijima, Nature 354 (1991) 56 – 8.[2] Thesis, et al. Science 273, 483 (1996).[3] M. Ahlskog, Ch. Laurent, M. Baxendale, M. Huhtala. “Electronic Properties and Applications of Carbon Nanotubes”. ISBN: 1-58883-059-4 Encyclopedia of Nanoscience and Nanotechnology.[4] J. González, “Electronic Properties of Carbon Nanotubes”. Consejo Superior de Investigaciones Científicas, Madrid, Spain. ISBN: 1-58883-059-4 Encyclopedia of Nanoscience and Nanotechnology.[5] Sajanlal, P., Sreeprasad, T., Samal, A., & Pradeep, T. (2011). Anisotropic nanomaterials: structure, growth, assembly, and functions. Nano Reviews, 2. doi:10.3402/nr.v2i0.5883.[6] Agarwal A., Bakashi S. R., Lahiri D., Carbon Nanotubes Reinforced Metal Matrix Composites, New York, CRC Press, 2011.[7] Inpil Kang, Yun Yeo Heung, Jay H. Kim, Jong Won Lee Ramanand Gollapudi, Srinivas Subramaniam, Suhasini Narasimhadevara, Douglas Hurd, Goutham R. Kirikera, Vesselin Shanov, Mark J. Schulz, Donglu Shi, Jim Boerio, Shankar Mall, Marina Ruggles-Wren. ”Introducction to CNT and nanofiber smart materials”,2006.[8] Hierold, Ch., Carbon Nanotube Devices, Weinheim, Wiley-vch, 2008.[9] Jeremy Ramsden, Cranfield University. “Nanotechnology: An Introduction”, Elsevier, 2011.[11] Baughman R. H., Zakhidov A. A. and de Heer, W. A.: Carbon nanotubes –the route toward applications. Science, USA 2002. [17] Veena Choudhary, B.P. Singh and R.B. Mathur. Chapter 9: Carbon Nanotubes and Their Composites, from Syntheses and Applications of Carbon Nanotubes and Their Composites. http://dx.doi.org/10.5772/52897. (2013).[19] Peng-Cheng Ma, Naveed A. Siddiqui, Gad Marom, Jang-Kyo Kim. Dispersion and functionalization of carbon nanotubes for polymer-based nanocomposites: A review. doi:10.1016/j.compositesa.2010.07.003. (2010).[26] “Nanostrucures for Energy Harvesting Applications”, Novel Functional Materials & Device Lab, Department of Physics, Hanyang University, http://nfmd.hanyang.ac.kr/korean/viewforum.php?f=124.
Faculty of Mechanical Engineering and Robotics
22
[28] Michele Kinman, Energy Harvesting, “Energy Harvesting for a Greener Environment”, www.energyharvesting.net, 2010.[30] Stephen R. Platt, Shane Farritor, and Hani Haider. On Low-Frequency Electric Power Generation With PZT Ceramics. DIO: 10.1109/TMECH.2005.844704. (2003).[33] Fundamentals of Piezoelectricity, Piezoelectric Transducers for Vibration Control and Damping, Advances in Industrial Control, Springer London, 2006, ISBN: 978-1-84628-331-4, DOI:10.1007/1-84628-332-9_2, http://dx.doi.org/10.1007/1-84628-332-9_2.[35] Na Kong, Dong Sam Ha, Alper Erturk and Daniel J. Inman. Resistive Impedance Matching Circuit for Piezoelectric Energy Harvesting. Journal of Intelligent Material Systems and Structures, DOI: 10.1177/1045389X09357971 http://jim.sagepub.com/content/early/2010/01/07/1045389X09357971, 2010 [36] C. K. Jeong, K. Park, J. Ryu, G. Hwang and K. Lee. Large-Area and Flexible Lead-Free Nanocomposite Generator Using Alkaline Niobate Particles and Metal Nanorod Filler. DOI: 10.1002/adfm.201303484. (2014).[37] K. Park, J.H. Son, G Hwang, Ch. Jeong, J Ryu, M. Koo, I. Choi, S.H. Lee, M. Byun, Z.L. Wang and K.J. Lee. Highly-Efficient, Flexible Piezoelectric PZT Thin Film Nanogenerator on Plastic Substrates. DOI: 10.1002/adma.201305659 (2014).[38] Indrani Dakua, and Nitin Afzulpurkar. Piezoelectric Energy Generation and Harvesting at the Nano-Scale: Materials and Devices. Nanomater. Nanotechnol, Vol. 3, Art. 21:2013. (2013).[39] K. Park, Ch. Jeong, J. Ryu, G. Hwang and K.J. Lee. Flexible and Large-Area Nanocomposite Generators Based on Lead Zirconate Titanate Particles and Carbon Nanotubes. DOI: 10.1002/aenm.201300458. (2013).[40] K. Park, M. Lee, Y. Liu, S. Moon, G. Hwang, G. Zhu, J.E. Kim, S.O. Kim, D.K. Kim, Z.L. Wang and K.J. Lee. Flexible Nanocomposite Generator Made of BaTiO3 Nanoparticles and Graphitic Carbons. DOI: 10.1002/adma.201200105. (2012).[44] Springer Handbook of Nanotechnology. Bharat Bhushan (Ed.). ISBN 3-540-01218-4.[48] Rotkin, S.V., Subramoney S.: Applied Physics of Carbon Nanotubes, New York, Springer, 2005.[70] https://team.inria.fr/cairn/wireless-sensor-networks/
Faculty of Mechanical Engineering and Robotics
References
23
Thank you very much for your attention
Dziękuję bardzo
ESKERRIK ASKO
Faculty of Mechanical Engineering and Robotics
Recommended