international institute for nanotechnology nanoscale science & engineering center for integrated...
Post on 27-Dec-2015
217 Views
Preview:
TRANSCRIPT
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nanotechnology:
BIG Ideas From Small Things
Mike Davis – Harold Washington CollegeRET Director: Northwestern University
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Outline
Brief Overview of Size and Scale Making Nanoparticles Arranging Nanoparticles Lithography Nanotechnology in Education Nanostructures – Gallery
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nanotechnology - Basics
Techniques that produce, manipulate or arrange particles that are less than 100nm in their largest dimension.
One nanometer is 1 billionth of a meter.
‘1 nanometer is the length a man’s beard grows when he picks up the razor’
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano Buzz
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nanotechnology – Surface Particles
Individual atoms can exhibit quantum effects. Groups of atoms can start to exhibit collective effects,
but are too big to have noticeable quantum effects. As particles get bigger, the number of particles on the
surface relative to the particles in the interior gets smaller.
Nanotechnology happens when the number of particles on the surface is similar to the number of particles in the bulk.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nanotechnology – Total number of Particles
Particle Size vs. Surface Percentage
0
20
40
60
80
100
120
0 5 10 15 20 25
Particles Size (length of a side nm)
Per
cent
age
Sur
face
Par
ticle
s
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nanotechnology – More than a size
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nanotech - Computing
Moore’s Law Doubling the
number of transistors on an integrated circuit every two years.
Enormous increase in computing power and memory.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
iPod Nano
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Demonstration
Bulk properties – Liquid Phase Reaction
Surface Properties – Gas Phase Reaction
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Gold Nano Particles
As these particles get larger, their color becomes more blue in appearance.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Making Gold Nanoparticles
Chemical Reaction
– Solvated form of the metal (gold or silver)– Introduction of a reducing agent (citrate or borohydride)– Slightly elevated temperature
Control over particle size (monodispersion)
– Light conditions– Temperature conditions– Stabilizing media
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Carbon Nanotubes
Made by passing an electrical arc between two graphite rods.
Seeded by small amounts of metal.
Can be grown to specific lengths, diameters, and wall thickness.
Stronger than steel. Electrically in some
configurations. Semiconductor in other configurations. Chiral in other configurations.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nanoparticle Synthesis – Wet Chemical
Chad Mirkin – Northwestern University
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano Printing Press – Micro contact Printing
A technique for modifying surfaces with a high degree of control.
Hydrophobic and hydrophilic regions on a gold surface (CDRs)
Inexpensive method to demonstrate a simple process.
Commonly used technique for surface modification.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano Printing Press – Microcontact Printing
Expose a gold surface on a CDR.
Pattern the surface with a hydrophilic organic molecule.
Dip the patterned surface in a solution with a hydrophobic organic molecule.
Dry the surface. Cool the surface below the
dew point. Observe the areas where
water condenses.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano Printing Press
Science is based on a strong bond between gold and sulfur (thiol).
Long organic molecule ends in something either hydrophilic or hydrophobic.
Microcontact printing uses a stamp made by pouring an elastic polymer over a mask.
Finer mask, finer features, more control.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Multiple Nano Features with One Mask
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Micro Contact Printing with Biological Samples - Whitesides
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nanoparticle Synthesis – Surfaces
Prepare a surface that has a pattern on it.
Use those patterns for growing crystals.
Teri Odom – Northwestern University
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Instrumentation – Visualizing the Nanoscale
Most nanofeatures are smaller than the visible wavelengths of light.
Can’t use visible light to determine surface features.
Electron microscopy (wavelength smaller than light)
Force micrscopy (no light used).
Tools of the trade.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Scanning Tunneling Microscope
A very sharp tip is brought near a surface.
A voltage is applied between the surface and tip.
Current is measured on the surface to determine the size and shape of features.
STM can resolve features that are 0.1nm wide and 0.01nm high.
Atomic resolution.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Atomic Force Microscopy (AFM)
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano-Analogy
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano – Analogy
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Lithographic Techniques – Solar Photography
Photo sensitive paper– Mixture of iron salts
Place an opaque object over the paper.
Expose the paper to light.– Opaque objects block out the
light and expose the rest of the salts.
– Exposed iron salts form an insoluble salt.
– Unexposed salts are water soluble.
Remove the object. Wash.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Lithographic Techniques in Nanotech
Techniques that build nanostructures or arrays.
Bottom – up approach– Prepare areas on a surface
– Utilize self assembly to build up from that point.
Top – down approach– Prepare a surface and etch
into it.
– Can involve some light based photochemistry.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Lithographic Techniques in Nanotech – Top Down Approach
Forming arrays of nanopyramids.
Colloidal crystal of nanospheres on a surface. (Mask)
Thermally deposit metal onto the top of the surface and the sphere mask.
Remove the sphere mask. Look at the pretty remaining
structures.VanDuyne – Nanoletters 2007
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Colloidal Crystals – Chiang MIT
282 nm 356 nm
482 nm 424 nm
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Colloidal Crystals – Chiang MIT
STM Images of Layers of Polystyrene Spheres on a Silicon substrate. Opals.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nanolithography – Bottom Up Approach
Pattern a surface with something.
Allow other species to assemble there spontaneously.
Grow upwards from the base. Whitesides – approach to
paper based telemedicine.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano in the Environment
Nanoparticles being made end up being released into the environment.
Unicellular and multicellular organisms pick up the particles.
Silver nanoparticles are antimicrobial.
What are the long term effects of exposure?
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano in Commercial Products
Sunscreen (TiO2 and ZnO)
Silver in bandages. Silver in plastic food
containers. Nanoscale fabrics on
stainresistant clothing. Carbon nanotubes in sporting
equipment. Particles in stained glass.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano-Imagination - Robots
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano-Imagination – Robots in the Blood
False – Blood Robots True – Nanoparticles to Treat Tumors
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano-Imagination – Reproduction
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano - Resources
NISE-Net: Network of Informal Educators and Researchers (nisenet.org).
MRS Nano Days:Free digital and physical activities for kids and adults. (nisenet.org/nanodays/2010)
National Lab Day: Localized resources for teachers. (Nationallabday.org)
Nanohub: Online resource for computational nanotech (nanohub.org)
iLabcentral: Forum for shared instrumentation. Nanotech coming. (ilabcentral.org)
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
Nano Resources Students - REU
Summer Research Experience for Undergraduates.
Spend the summer working in a lab group.
Potential for a publication. 8 – 10 weeks. On campus housing Stipend ~$4,500 REU sites all over the US www.nsec.northwestern.edu/
REU Applications due in Feb.
International Institute for NanotechnologyNanoscale Science & Engineering Center for Integrated Nanopatterning and Detection TechnologiesNorthwestern University
AcknowledgementsKathy Cook
Margaret Connolly
NSF – EEC 0118025 / NSF – EEC 0647560
Questions / Concerns / Comments
top related