bimat sensorsactuators 10'04

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Bio-Inspired Sensing and Actuation
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BioNanotechnology for Sensing and Actuation
Sensing Sensors Lab-on-a-chip
High SA coatings for chemical sensitization Canti
lever sensors
Fluoropolymer nanopillars
Chem/Bio
Photon
light harvesting Nanoparticle composites
Biomimetic Lens arrays for photonics
State Variables T, P
SWNT/Polyimide For Temperature /Pressure sensing
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BioNanotechnology for Sensing and Actuation
Electronics
Nanoparticle composites for On-chip photovoltaics
Integrated Sense/Electronics
Sense/control
Organic FETs for flexible electronics/
integrated sense control
Special Purpose
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BioNanotechnology for Sensing and Actuation
NanoMechanisms/Actuators
NEMS devices
SWNT oscillators sensing/switching
Actuating nanoarrays Lab-on-a-chip fluidics
SWNT composites for actuators
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Towards Integrated Intelligent Systems
Multi-Scale Fabrication
Biomimetic Structures
Magnetic Assembly
BioMolding
Breath Figure Templates
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Biomimetic MicroPatterning

• Vesicle /Breath figure Assembly
• Galen Stucky
• University of California, Santa Barbara

BioMolding Ed Samulski University of North
Carolina, Chapel Hill
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Biomimetic Design of Materials
SEM images of the peripheral layer of a dorsal
arm plate from the brittle star Ophiocoma wendtii
showing the microlens array
vesicle templating mechanism for diatoms
assemblages of vesicles and other bilayer
structures.
Silicic skeletons of diatoms show complex and
finely carved morphologies in SEM
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Optical arrays from breath figures
concave
Condensed vapor forms initial pattern
convex
Hierarchical Surfaces
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Biomolded Lens Arrays The eyes have it.
Liquid Teflon microlens array directly from flys
eye! Create negative mold from fly infinite
copies
Ed Samulski UNC
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Functional Titania-Based NanocompositesControllin
g Light Lasing and Harvesting

• Galen Stucky
• Univeristy of California, Santa Barbara

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Functional Titania-Based Nanocomposites

• One pot single precursor synthesis approach
• Anatase in amorphous TiO2
• Doped w/Rh6g, rare earth ions, Qdots

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Titania-Based Nanocomposites Lasing

• Crack-free fibers and films
• Waveguiding ability
• Doped with Rh6G for mirrorless lasing

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Titania-Based NanocompositesPhotoCell apps

• Use semiconductor nanocrystals to sensitize TiO2
  in visible
• Qdots colocated with nanocrystals
• Generate photocurrent from visible light

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Biomimetic Active Surfacesfor Adhesion/Fluidics
Control

• Richard Superfine, Ed Samulski
• Physics/Astronomy, Chemistry
• University of North Carolina
• Chapel Hill, NC

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Biomimetic Silia
BioInspiration live human lung cell cultures
Deliverables

• Astronaut Environment
• Control BioAdhesion and Biofouling
• Microfluidic Medical Diagnostics
• Control Wetting, Mixing, Biomolecule Manipulation
• Control Material Adhesion
• Aerodynamics
• Drag Control on Surfaces

• Goal Produce Engineered Versions with variety of
  materials/Geometries

Superfine, UNC
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Controlling Nanocilia Wetting properties

• Electrically Switchable adhesion
• Electrically controlled wetting
• Displays, microfluidic manipulation

AAO membrane
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Biomimetic Control of Fluidics and Adhesion

• Magnetic Instability Fabrication
• FeO 10nm particles in PDMS
• Magnetic field Nanoscale Spiking!

Fe2O3 10nm diameter
Balance of Magnetic Energy and Surface Energy
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Biomimetic Control of Fluidics and Adhesion

• Large area arrays
• Actuation in applied fields

Magnetic field actuation
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States of droplets on structured surfaces

• Surface Geometry can prevent Liquid Contact
• Instability can induce geometrical wetting

Wenzel State
Cassie State
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Actuated Cilia Applications BioMicrofluidics

• nanorod spinning experiments modeled by theory
  (Applied Math UNC)
• Nanoscale Mixing
• DNA Stretching

Spinning Rod
Mixing
DNA Stretching
l-DNA (14 mm)
Experiment
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Resonators for sensing/actuation

• Piezo Microcantilevers and High Sensitivity
  Coatings
• Ilhan Aksay, Jeffrey D. Carbeck
• Princeton University

NEMS resonators R. Superfine, S.
Washburn University of North Carolina, Chapel Hill
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Motivation
Biosensors
Chiral Recognition Gas Sensors
Wu, G. Datar, R. Hansen, K. Thundat, T. Cote,
R. and Majumdar, A. Nature 2001, 19, 856.
Gpel et Al., Nature 1997,387, 577 -580
Electronic Nose
Nerve Gas Detection
United States Patent No. 5289715, E. J. Staples,
Electronic Sensor Technology.
Gimzewski et Al. An Electronic Nose based on a
micromechanical cantilever array, Unpublished.
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Piezoelectric Microcantilevers with Nanoscopic
Coatings
I.A. Aksay, D.M. Dabbs and J.D. Carbeck,
Princeton University
Objectives
Approach

• Fabrication of micro piezoelectric cantilevers
  via sol gel processing
• Enhancement of detection sensitivity through
  nanoscopic coatings
• Theoretical and experimental analysis of the
  geometrical variations on detection sensitivity

• Development of miniature mechanical sensors for
  in-situ detection.
• Enhancement of detection sensitivity
• Miniaturization, optimal geometry
• Increase effective surface area

Outcomes
Products

• Increased mass sensitivity through
  miniaturization and geometry optimization
• Developed new technique to process ferroelectric
  pzt microcantilevers
• Enhanced the mass detection sensitivity of QCMs
  via nanoscopic silica coatings

PZT microcantilever
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Benchmark Silicon-Based Microcantilever
Laser Diode
Photodetector
Focusing Optics
Cantilever

• Silicon-based cantilevers
• Disadvantages
• Not piezoelectric
• Rely on a driver for actuation and a complex
  optical system for detection
• Q factor ? 1 in water, in-vivo detection
  difficult

T. Thundat, E.A. Wachter, S.L. Sharp, R.J.
Warmack, Appl. Phys. Lett., 66, 1695 (1995). B.
Ilic, et al., Appl. Phys. Lett., 77, 450 (2000).
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Motivation Piezoelectric Cantilevers for Sensing

• Simple electric actuation and detection
• High Q factor in water (? 40)

Dm
PZT
Stainless Steel
W.Y. Shih, X. Li, H. Gu, W.-H. Shih, I.A. Aksay,
J. Appl. Phys., 89, 1497 (2001).
Resonance frequency shifts with Dm
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Miniaturization

• Cantilevers permit measurement of applied forces
  and mass with high sensitivity
• Use of ferroelectric materials eliminates need
  for optical detection schemes
• Miniaturization takes advantage of scaling
  analysis predictions
• Predicted sensitivity of 10-15 g for
  micrometer-scale cantilevers
• Ferroelectric materials offers greater design
  flexibility than Quartz Crystal Microbalance
• Easier to microfabricate
• Ability to tailor piezoelectric properties
• Potential for integration in MEMS

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MicroChannel Molding

• Used principles of MIMIC to develop own
  patterning technique
• Transfer pattern directly into substrate to
  obtain impermeable sidewalls
• One-dimensional uniform drying across entire
  width
• Accelerated drying at corners eliminated
• Complete network capillary channels with flat
  PDMS membrane
• Use same capillary filling procedure as MIMIC

C.R. Martin, I.A. Aksay, J. Mater. Res. accepted
Apr 2005
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µCM Results

• High wetting affinity of PZT to Si problematic
• Meniscus shape develops due to low contact angle
  at sidewalls
• Inability to release stress laterally during
  shrinkage
• Matching of contact angles with OTS on sidewalls
  allows sol-gel to dewet from all corners equally
• Permits lateral and vertical shrinkage
• Cost of weaker adhesion to substrate

10 µm
Si
PZT
2 µm
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Focused-Ion Beam Cantilever Fabrication

• Pattern PZT by MIMIC on Pt-coated Si wafer
• Coat whole surface with SiNx
• Electrical insulation
• Mask for KOH wet etch
• Pattern Pt top electrode on PZT section that will
  become cantilever
• Cut cantilever pattern

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PZT Microcantilevers

• After 300 min KOH wet chemical etch

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Summary

• Topographical evolution of MIMIC patterned thin
  films from sol-gel studied and understood
• Developed µCM to pattern rectangular
  cross-section patterns
• PZT cantilever structures fabricated using soft
  lithography, FIB electrode deposition and
  patterning, followed by KOH wet chemical etch
• Resistive current across sample swamps out
  capacitance current and ferroelectric properties
• Cause is due to processing with FIB
• Ion milling damages sidewalls
• Pt deposition overspray results in short circuit
• Ferroelectricity of directly patterned thin films
  is retained

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Devices and Sensors CNT-NEMS

• Collaboration w/NASA Wincheski Group,
  nanoManipulator System, Postdoc
• CNT oscillators

Measure stiffness using combined AFM inside SEM
Freely suspended paddle w/ single CNT torsion
spring
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Devices and Sensors CNT-NEMS

• Collaboration w/NASA Wincheski Group,
  nanoManipulator System, Postdoc
• CNT oscillators

Freely suspended paddle
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Enhancing Sensitivity via Nanostructured Coatings
Uncoated Macrocantilever
Coated Macrocantilever
Coated Macrocantilever Probe Molecule
Coated Microcantilever Receptor
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Enhancing Sensitivity
We use three different surface coatings to show
the effects of accessibility, surface area and
uniformity of films on the sensitivity of a
resonator
Characteristic feature size distribution
Feature size
Accessible lengths Non accessible lengths
Surface area Uniformity
Accessibility
Uniformity
Surface area
Surface area
Uniformity
Accessibility
Accessibility
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Comparison Plots
L3 silica (with surfactant)
Hexagonal
Xerogel
Since the surface chemistry is the same for the
three coatings, the differences in sensitivity
come from the nano-structure of the films
Yao et al. Chem. Mat. 2000 McGrath, K. M. et al.
Science 277 (1997) 552
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Important Length Scales
Surfactant mesophase
Surfactant mesophase templated silica
Increasing length scales
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Effects of Annealing on the larger Length Scales
Long Annealing
Short Annealing
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Summary

• Increased mass detection sensitivity through
  miniaturization and geometry optimization
  (theoretical and experimental)
• Developed a new technique (microchannel molding)
  to process ferroelectric pzt microcantilevers
  without shape distortion
• Demonstrated that L3 nanoscopic silica coatings
  enhance the mass detection sensitivity of QCMs

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Collaborators

• Galen Stucky -- Templated Silicates
• Daniel Morse, Herb Waite -- Bio-inspiration for
  sensing
• Rod Ruoff -- Characterization of PZT
• Ed Samulski -- PZT whiskers (integration)
• Zoubeida Ounaies (VCU) -- Embedded PZT in
  polyimide composites
• Jean Prevost -- Theory and modeling of
  adsorption, condensation and transport

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Flexible Organic Sensor
Gene Irene University of North Carolina
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Flexible Organic Sensor Materials and Devices

• Objective To develop all organic flexible
  mechanical sensor
• Integrate sensing electronics for structural
  monitoring
• Integrate electronics and fabrics (clothing, etc.)

• Approach Prepare Films of Selected Materials
  Spin coating
• Select Materials
• High K Dielectric and Piezoelectric -
  (PVDF/TrFE), SWNT polyimide
• N-Type Semiconductor (NDA-n2) P-Type (poly
  o-methoxyaniline -POMA)
• Optical (Spectroscopic Ellipsometry) and Chemical
  Properties
• Electronic C-V and I-V K, Leakage,
  Conductivity etc.
• Device Fabrication and Testing

E.A. Irene (with Dr. Li Yan, R. Shrestha, D.X.
Yang and Y.X. Li (UNC) in collaboration with Z.
Ounaies, C. Park (NIA), E.T. Samulski (UNC), T.
Dingemans
E. A. Irene (UNC)
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Prototype O-FET Stress Sensor
Organic Semiconductor
Organic Piezoelectric/Dielectric

• Future Plans
• Electronic Characterization
• Prepare on Flexible Substrate
• Stress Testing

Irene et al
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Spin Cast of Piezoelectric Polyimide Solution

• Spin Cast (co-solvent)
• Ex Situ Study of Thin Spin Cast Film
• (FTIR, UV-Vis absorbance spectroscopy,
  ellipsometry, AFM, and XRD)
• In Situ and Real-Time Monitoring of PAA Cure

Co-solvent
E. A. Irene, L. Yan (UNC) and NIA
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In Situ Real-Time Monitoring of PAA Cure
Spectroscopic ellipsometry
Custom-built vacuum system
L. Yan, C. Park, Z. Ounaies, and E. A. Irene, in
preparation.
E. A. Irene, L. Yan (UNC) and NIA
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SWNT/ Polypeptide Nanocomposites Sensors/Actuators
National Institute of Aerospace

• Sonic fatigue abatement
• Noise transmission attenuation
• Wing and panel flutter control
• Tail buffet alleviation control
• Surface shape control
• Space Suit Habitat

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Collaborator NASA LaRC Harrison, Siochi
SWNT/Polymer Nanocomposites
Electroactive High Performance Polyimide

• In-situ Polymerization under
• sonication and shear
• Donor-Acceptor interaction

(b-CN)APB/ODPA (Tg 220C)
Good Dispersion
Polyimide SWNT
Park, et al., Chem. Phys. Lett., 364 303 (2002)
Wise, Park et al, Chem. Phys. Lett. 391 207 (2004)
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Sensors
Collaborator NASA LaRC (Harrison, Siochi,
Wincheski, Watkins)
SWNT/Polyimide Nanocomposite Sensor
Dynamic
Static
10 SWNT
0.2 SWNT
Load sensor Strain sensor
National Insitute of Aerospace
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Sensors Temperature and Pressure
Collaborator NASA LaRC (Harrison, Wincheski,
Watkins)
NASA LAR 16857 17112 (2005)
National Insitute of Aerospace
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Actuator Out-of Plane Strain
Collaborator NASA LaRC Harrison, Lowther
Fiber Optic sensors
2 at 0.8 MV/m
S33 SE (Electrostriction) SM (Maxwell
effect)
103 104 times higher
Electrostrictive coefficient SWNT/Polyimide M33
-3.6E-15m2/V2 -1.2E-13m2/V2 Polyurethane M33
-4.6E-18m2/V2 -1.6E-17m2/V2
lt 0.01
NASA LAR 16857 17112 (2005)
National Insitute of Aerospace
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Actuator Bending
Collaborator NASA LaRC Harrison, Lowther
No EF
EF 0.8 MV/m
Sonic fatigue abatement Noise transmission
attenuation Wing and panel flutter control Tail
buffet alleviation control Surface shape control
M31 2.86 x 10-15 (m2/V2) 102103 times higher
than PU
NASA LAR 16857 17112 (2005)
National Insitute of Aerospace
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Electromechanical Properties of Materials
Actuate Large Strain at Very Low Energy Input
Key for Long-term Space Exploration
National Insitute of Aerospace
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Bio-Inspired BioNanocomposite Actuation
Leucine-Phenylalanine SWNT
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BioNanotechnology for Sensing and Actuation
Sensing
Chem/Bio
Photon
Sense T, P
Electronics
Flexible Organic Electronics
Integrated Sense/Electronics
NEMS/Actuators
Multi-Scale Fabrication
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Bioinspired Sensors/Actuators for NASA
Astronaut Environment/Health
Capsule Control/Sense
Photon Control
Multiscale Fabrication
Chem/Bio
Flexible Organic Electronics
Integrated Sense/Actuate SWNT nanocomposites