Elastodynamics of Inorganic
and Polymer Sculptured Thin
Films
Akhlesh Lakhtakia
NanoMM –– Nanoengineered Metamaterials Group
Department of Engineering Science and Mechanics
Pennsylvania State University
7th Iberian Vacuum Meeting
5th European Topical Conference on Hard Coatings
Caparica, Portugal
June 25, 2008
Elastodynamics of Inorganic
and Polymer Sculptured Thin
Films
Akhlesh Lakhtakia
NanoMM –– Nanoengineered Metamaterials Group
Department of Engineering Science and Mechanics
Pennsylvania State University
7th Iberian Vacuum Meeting
5th European Topical Conference on Hard Coatings
Caparica, Portugal
June 25, 2008
• Nanotechnology
• Metamaterials
•Sculptured Thin Films
• Nanotechnology
A. Lakhtakia
Nanotechnology: The term
Norio Tanaguchi (1974):
‘Nano-technology’ mainly consists of the
processing of separation, consolidation, and
deformation of materials by one atom or one
molecule.
N. Taniguchi, On the Basic Concept of 'Nano-Technology', Proc. Intl. Conf. Prod. Eng. Tokyo, Part II, Japan
Society of Precision Engineering, 1974.
A. Lakhtakia
Nanotechnology: The term
US Patents and Trademarks Office
(2006):
“Nanotechnology is related to research and technology
development at the atomic, molecular or macromolecular
levels, in the length of scale of approximately 1-100
nanometer range in at least one dimension; that provide a
fundamental understanding of phenomena and materials at
the nanoscale; and to create and use structures, devices and
systems that have novel properties and functions because of
their small and/or intermediate size.”
A. Lakhtakia
Nanotech Economy
Total worldwide R&D funding
=
$ 9.6B in 2005
Governments (2005):
$4.6B
Established Corporations (2005):
$4.5B
Venture Capitalists (2005):
$0.5B
Source: Lux Research, The Nanotech Report, 4th Ed. (2006).
A. Lakhtakia
Nanotech Economy: Scope
Source: Meridian Institute, Nanotechnology and the Poor: Opportunities and Risk (2005)
A. Lakhtakia
Nanotechnology
promises to be
• pervasive
• ubiquitous
A. Lakhtakia
Source:
Nanotechnology & Life
A. Lakhtakia
Nanotechnologies?
• Metamaterials
A. Lakhtakia
Engineers
and
Composite Materials
A. Lakhtakia
Evolution of Materials
Research
• Material Properties (< ca.1970)
• Design for Functionality
(ca.1980)
• Design for System Performance
(ca. 2000)
A. Lakhtakia
Evolution of Materials
Research
• Material Properties (< ca.1970)
• Design for Functionality
(ca.1980)
• Design for System Performance
(ca. 2000)
A. Lakhtakia
Evolution of Materials
Research
• Material Properties (< ca.1970)
• Design for Functionality
(ca.1980)
• Design for System Performance
(ca. 2000)
A. Lakhtakia
Multifunctionality
Multifunctionality
A. Lakhtakia
Multifunctionality
A. Lakhtakia
Performance Requirements on the Fuselage
1. Light weight (for fuel efficiency)
2. High stiffness (resistance to deformation)
3. High strength (resistance to rupture)
Multifunctionality
A. Lakhtakia
Performance Requirements on the Fuselage
1. Light weight (for fuel efficiency)
2. High stiffness (resistance to deformation)
3. High strength (resistance to rupture)
4. High acoustic damping (quieter cabin)
5. Low thermal conductivity (less condensation;
more humid cabin)
Multifunctionality
A. Lakhtakia
Performance Requirements on the Fuselage
1. Light weight (for fuel efficiency)
2. High stiffness (resistance to deformation)
3. High strength (resistance to rupture)
4. High acoustic damping (quieter cabin)
5. Low thermal conductivity (less condensation;
more humid cabin)
Multifunctionality
A. Lakhtakia
Performance Requirements on the Fuselage
1.
2.
3.
4.
5.
Light weight (for fuel efficiency)
High stiffness (resistance to deformation)
High strength (resistance to rupture)
High acoustic damping (quieter cabin)
Low thermal conductivity (less condensation; more humid cabin)
Future: Conducting & other fibers for
(i) reinforcement
(ii) antennas
(iii) environmental sensing
(iv) structural health monitoring
(iv) morphing
A. Lakhtakia
Metamaterials
Rodger Walser
SPIE Press (2003)
A. Lakhtakia
Walser’s Definition (2001/2)
• macroscopic composites having a
manmade, three-dimensional, periodic
cellular architecture designed to
produce an optimized combination, not
available in nature, of two or more
responses to specific excitation
A. Lakhtakia
“Updated” Definition
composites designed to produce an
optimized combination of two or more
responses to specific excitation
Cellularity
Nanoengineered Metamaterials
A. Lakhtakia
Cellularity
Multifunctionality
Nanoengineered Metamaterials
A. Lakhtakia
Cellularity
Multifunctionality
Morphology
Performance
Nanoengineered Metamaterials
A. Lakhtakia
Multi-component system = Assembly of different components
Component:
Simple action
Assembly of components:
Complex action
Nanoengineered Metamaterials
A. Lakhtakia
Energy harvesting cell
Chemisensor cell
Energy storage cell
Force-sensor cell
Energy distributor cell
RFcomm cell
IRcomm cell
Shape-changer cell
Light-source cell
Nanoengineered Metamaterials
A. Lakhtakia
Supercell
Nanoengineered Metamaterials
A. Lakhtakia
Periodic Arrangement of Supercells
Fractal Arrangement of Supercells
Functionally Graded Arrangement of Supercells
Nanoengineered Metamaterials
A. Lakhtakia
Biomimesis
Nanoengineered Metamaterials
A. Lakhtakia
Biomimesis
Nanoengineered Metamaterials
A. Lakhtakia
Fabrication
1. Self-assembly
2. Positional assembly
3. Lithography
4. Etching
5. Ink-jet printing
6. ….
7. ….
8. Hybrid techniques
Nanoengineered Metamaterials
A. Lakhtakia
Fabrication
1. Self-assembly
2. Positional assembly
3. Lithography
4. Etching
5. Ink-jet printing
6. ….
7. ….
8. Hybrid techniques
•Sculptured Thin Films
A. Lakhtakia
Sculptured Thin Films
Assemblies of Parallel Curved Nanowires/Submicronwires
Controllable Nanowire Shape
A. Lakhtakia
Sculptured Thin Films
Assemblies of Parallel Curved Nanowires/Submicronwires
Controllable Nanowire Shape
A. Lakhtakia
Sculptured Thin Films
Morphological
Change
A. Lakhtakia
Sculptured Thin Films
Assemblies of Parallel Curved Nanowires/Submicronwires
Controllable Nanowire Shape
2-D morphologies
3-D morphologies
vertical sectioning
Nanoengineered Materials (1-3 nm clusters)
Controllable Porosity (10-90 %)
A. Lakhtakia
Sculptured Thin Films
Antecedents:
(i)
Young and Kowal - 1959
(ii) Niuewenhuizen & Haanstra - 1966
(iii) Motohiro & Taga - 1989
Conceptualized by Lakhtakia & Messier (1992-1995)
Optical applications (1992-1995)
Biological applications (2003-)
A. Lakhtakia
Sculptured Thin Films
Research Groups
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
(xiii)
(xiv)
(xv)
(xvi) Imperial College, London
Penn State
(xvii) University of Glasgow
Edinboro University of Pennsylvania
(xviii)University of Edinburgh
Lock Haven University of Pennsylvania
(xix)University of Leipzig
Millersville University
(xx) ENSMM, Besançon
Rensselaer Polytechnic University
(xxi) Toyota R&D Labs
University of Arkansaa, Little Rock
(xxii) Kyoto University
University of Toledo
(xxiii) Hanyang University
University of Georgia
(xxiv) University of Otago
University of South Carolina
(xxv) University of Canterbury
University of Nebraska at Lincoln
(xxvi) Ben Gurion University of the
Pacific Northwest National Laboratory
Negev
University of Alberta
(xxvii) University of Campinas
Queen’s University
University of Moncton
National Autonomous University of Mexico
A. Lakhtakia
Physical Vapor Deposition
A. Lakhtakia
Physical Vapor Deposition
(Columnar Thin Films)
A. Lakhtakia
Physical Vapor Deposition
(Sculptured Thin Films)
Rotate about
y axis for
nematic
morphology
Rotate about
z axis for
helicoidal
morphology
Combined
rotations for
complex
morphologies
A. Lakhtakia
Sculptured Thin Films
Optical Devices:
Polarization Filters
Bragg Filters
Ultranarrowband Filters
Fluid Concentration Sensors
Bacterial Sensors
Biomedical Applications:
Tissue Scaffolds
Surgical Cover Sheets
Other Applications:
Photocatalysis (Toyota)
Thermal Barriers (Alberta)
Energy Harvesting (Penn State,
Toledo)
A. Lakhtakia
Optics of Chiral STFs
Chiral STFs: Circular Bragg Phenomenon
A. Lakhtakia
Chiral STF as CP Filter
A. Lakhtakia
Spectral Hole Filter
A. Lakhtakia
Fluid Concentration Sensor
A. Lakhtakia
Optical Modeling of STFs
Dielectric Materials
A. Lakhtakia
Optical Modeling of STFs
Locally Orthorhombic Continuums
A. Lakhtakia
Optical Modeling of STFs
Homogenize a
collection of
parallel ellipsoids
to get
Sherwin and Lakhtakia (2001-2003):
Bruggeman formalism
Mathematica
Program
A. Lakhtakia
Optical Modeling of STFs
Wave Propagation
Mathematica
Program
A. Lakhtakia
LIGHT EMITTERS
• Luminophores inserted in a chiral STF
• Co- and contra-wound photonic source filaments
• Calculations using Maxwell equations
- volume fraction of filaments
- wavelength
- co/contra-wound
A. Lakhtakia
LIGHT EMITTERS
• Co/contra-wound:
Clear differences in
(i) polarization state
(ii) emission bandwidth
• Dependence on tilt angle
Lakhtakia, Microw. Opt. Technol. Lett. 37, 37 (2003)
A. Lakhtakia
LIGHT EMITTERS
• Quantum dots inserted in a cavity between two
left-handed chiral STFs
Zhang et al., Appl. Phys. Lett. 91, 023102 (2007).
A. Lakhtakia
LIGHT EMITTERS
• Quantum dots inserted in a cavity between two
left-handed chiral STFs
LCP Emission Peak
Spectral Hole
A. Lakhtakia
Polymeric STFs
A. Lakhtakia
PARYLENE-C STFs:
COMBINED CVD+PVD TECHNIQUE
Pursel et al., Polymer 46, 9544 (2005)
A. Lakhtakia
PARYLENE-C STFs:
COMBINED CVD+PVD TECHNIQUE
1. Vaporize the dimer at 150 deg C
2. Monomerize at 680 deg C and 0.5 Torr
3. Release the monomer vapor through a nozzle
towards a substrate
4. Polymerization into STFs
A. Lakhtakia
PARYLENE-C STFs:
COMBINED CVD+PVD TECHNIQUE
Nanoscale
Morphology
Ciliary Structure
A. Lakhtakia
BIOSCAFFOLDS
A. Lakhtakia
BIOSCAFFOLDS
Lakhtakia et al., Adv. Solid State Phys. 46, 295 (2008).
A. Lakhtakia
•
•
•
•
•
Applications of Parylene STFs
Cell-culture substrates
Coatings for prostheses (e.g. stents)
Coatings for surgical equipment (e.g., catheters)
Biosensors
Tissue engineering for controlled drug release
Volumetric functionalization
Optical monitoring
A. Lakhtakia
STFs WITH TRANSVERSE
ARCHITECTURE
A. Lakhtakia
STFs WITH TRANSVERSE ARCHITECTURE
Metal STFs on
Topographic
Substrates
Chromium
Aluminum
Molybdenum
Horn et al., Nanotechnology 15, 303 (2004).
A. Lakhtakia
STFs WITH TRANSVERSE ARCHITECTURE
Dielectric
STFs on
Topographic
HCP array of SiOx nanocolumns Substrates BCC array of SiOx nanocolumns
1um x 1um mesh of SiOx nanolines
A. Lakhtakia
MECHANICAL
CHARACTERISTICS
MECHANICAL CHARACTERISTICS
A. Lakhtakia
1. Structural Integrity
2. Mechanical Tuning of Optical Properties
Pressure Sensors
Temperature Sensors
3. Acoustic Devices
Shear Wave Filters
STRUCTURAL INTEGRITY
A. Lakhtakia
Nanoindentation of SiO Chiral STFs
Seto et al., J. Vacuum Sci. Technol. B 17, 2172 (1999)
STRUCTURAL INTEGRITY
A. Lakhtakia
Nanoindentation of SiO Chiral STFs
Simple Theory: Chiral STF is a bed of parallel (macroscopic) springs
Seto et al., J. Vacuum Sci. Technol. B 17, 2172 (1999)
STRUCTURAL INTEGRITY
A. Lakhtakia
Nanoindentation of SiO Chiral STFs
Simple Theory: Chiral STF is a bed of parallel (macroscopic) springs
Seto et al., J. Vacuum Sci. Technol. B 17, 2172 (1999)
STRUCTURAL INTEGRITY
A. Lakhtakia
Nanoindentation of Chromium Zigzag STFs
Simple Theory: STF is a bed of parallel (macroscopic) springs
Better continuum model of each spring.
Lintymer et al., Thin Solid Films 503, 177 (2006)
STRUCTURAL INTEGRITY
A. Lakhtakia
Nanoindentation of Chromium Zigzag STFs
Simple Theory: STF is a bed of parallel (macroscopic) springs
Better continuum model of each spring.
Experimental
Experimental
Models
Lintymer et al., Thin Solid Films 503, 177 (2006)
STRUCTURAL INTEGRITY
A. Lakhtakia
Nanoindentation of Chromium Zigzag STFs
Simple Theory: STF is a bed of parallel (macroscopic) springs
Better continuum model of each spring.
Experimental
Experimental
Models
Lintymer et al., Thin Solid Films 503, 177 (2006)
MECHANICAL TUNABILITY OF OPTICAL FILTERS
A. Lakhtakia
Chiral STF is a circular-polarization Bragg filter
Center wavelength ~ Period x Effective RI
FWHM ~ Period x Linear Birefringence
Wang et al., J. Modern Opt. 50, 239 (2003)
MECHANICAL TUNABILITY OF OPTICAL FILTERS
A. Lakhtakia
Chiral STF is a circular-polarization Bragg filter
Center wavelength ~ Period x Effective RI
FWHM ~ Period x Linear Birefringence
Wang et al., J. Modern Opt. 50, 239 (2003)
MECHANICAL TUNABILITY OF OPTICAL FILTERS
A. Lakhtakia
Shift of center wavelength ~ DC Voltage
Wang et al., J. Modern Opt. 50, 239 (2003)
MECHANICAL TUNABILITY OF OPTICAL FILTERS
A. Lakhtakia
FWHM does not change
Wang et al., J. Modern Opt. 50, 239 (2003)
MECHANICAL TUNABILITY OF LIGHT-EMITTERS
A. Lakhtakia
Dye-doped polymer chiral STF
Light-emitters
Wang et al., Sens. Actuat. A 102, 31 (2002)
A. Lakhtakia
LINEAR ELASTODYNAMIC MODEL
Of a CHIRAL STF
Hooke’s Law
Kelvin notation
Compliance
Lakhtakia, J. Compos. Mater. 36, 1277 (2002)
A. Lakhtakia
LINEAR ELASTODYNAMIC MODEL
Of a CHIRAL STF
Hooke’s Law
Kelvin notation
Compliance
Lakhtakia, J. Compos. Mater. 36, 1277 (2002)
A. Lakhtakia
LINEAR ELASTODYNAMIC MODEL
Of a CHIRAL STF
Compliance
Lakhtakia, J. Compos. Mater. 36, 1277 (2002)
A. Lakhtakia
LINEAR ELASTODYNAMIC MODEL
Of a CHIRAL STF
Compliance
Homogenize a collection of
parallel ellipsoids
to get
Lakhtakia, J. Compos. Mater. 36, 1277 (2002)
A. Lakhtakia
LINEAR ELASTODYNAMIC MODEL
Of a CHIRAL STF
Compliance
Homogenize a collection of
parallel ellipsoids
to get
Lakhtakia, J. Compos. Mater. 36, 1277 (2002)
Mori-Tanaka
formalism
A. Lakhtakia
LINEAR ELASTODYNAMIC MODEL
Of a CHIRAL STF
Solve Navier’s equation
A. Lakhtakia
LINEAR ELASTODYNAMIC MODEL
Of a CHIRAL STF
Solve Navier’s equation
• Nanotechnology
• Metamaterials
•Sculptured Thin Films
A. Lakhtakia