Download presentation
Presentation is loading. Please wait.
Published byPercival Short Modified over 9 years ago
1
Nano
5
Slow-Releasing Nanoburrs From herbal tea
6
Honeybee's two compound eyes
7
Up Close With Your Tongue
8
Sugar
9
Single layer of graphene
10
Pollen
11
What's Measured Gets Managed. What do you measure?
12
FNI 1B12 Common Unit Conversions used in Nanoscience 1 m = 100 cm 1 m = 1,000 mm 1 m = 1,000,000 μm = 10 6 μm 1 m = 1,000,000,000 nm = 10 9 nm 1 m = 10,000,000,000 Å = 10 10 Å 1 cm = 10 7 nm 1 cm = 10 8 Å 1 mm = 1,000 μm 1 μm = 1,000 nm 1 μm = 10,000 Å nm – measure atomic structure Å – measure light waves
13
One nanometer = 3 silicon atoms in a row 1 millimeter = 1,000,000 nanometers 1,000,000 nanometers cm inches
16
IBM logo made up of 35 atoms of xenon on nickel 17 nanometres long and was made with a scanning tunnelling microscope in 1986
19
Spider’s Skin
20
Human Hair with Lice
21
The tree-like structures in this scanning electron microscope image of a cross section of a butterfly wing are on the undersides of the Morpho's wing scale ridges. These microribs reflect light to create iridescent colors. The Blue Morpho is common in Central and South America and known for its bright blue wings. However, these iridescent colors are created not by pigments in the wing tissues but instead by the way light interacts with nanometer-sized structures on the Morpho's wing scales. This effect is being studied as a model in the development of new fabrics, dye-free paints, and anti- counterfeit technologies for currency.
22
Structure of butterfly wing
23
Based on this discovery of butterflies wing structure, engineers are developing single sensors that are tailored to detect certain types of chemical agents or explosives. These sensors light up when they encounter threats.
25
Small, smaller, "nano" data storage! Metallofullerene Model 80 carbon atoms (light blue) 3 dysprosium atoms (red) 1 nitrogen atom (dark blue)
26
Small, smaller, "nano" transport of very small Nanotube
27
T4 Bacteriophage - a virus
28
Your Brain 1.There are approximately 50,000,000 neurons per square centimeter (50X10 6 per cm 3 ) 2.Each cm 3 neurons have axons that reach out to create 1 trillion synapse (1×10 12) 3.If each synapse can express 8 bits or 1 byte of information, than 1 cm 3 contains 1 terabyte of data (1×10 12 ) 4.The human brain is roughly 1000 cm 3 in size which means it can store about 1 petabyte of data (1×10 15 ) 5.That is about 1/3 as much data as stored in the entire internet … in one average human brain. So when will a computer the size of a brain match its capacity? By current rates of change it looks like we will be there between 2025 and 2030.
29
Brain Cell – Soma and Dendrites
30
Snail neuron grown on a chip that records the neuron’s activity
32
Properties of a Material A property describes how a material acts under certain conditions Types of properties – Optical (e.g. color, transparency) – Electrical (e.g. conductivity) – Physical (e.g. hardness, melting point) – Chemical (e.g. reactivity, reaction rates) Properties are usually measured by looking at large (~10 23 ) aggregations of atoms or molecules 32 Sources: http://www.bc.pitt.edu/prism/prism-logo.gif http://www.physics.umd.edu/lecdem/outreach/QOTW/pics/k3-06.gif
33
Optical Properties Change: Color of Gold Bulk gold appears yellow in color Nanosized gold appears red in color – The particles are so small that electrons are not free to move about as in bulk gold – Because this movement is restricted, the particles react differently with light 33 Sources: http://www.sharps-jewellers.co.uk/rings/images/bien-hccncsq5.jpg http://www.foresight.org/Conferences/MNT7/Abstracts/Levi/ 12 nanometer gold clusters of particles look red “Bulk” gold looks yellow
34
Electrical Properties Change: Conductivity of Nanotubes Nanotubes - long, thin cylinders of carbon – 100 times stronger than steel, very flexible, – unique electrical properties Their electrical properties change with diameter, “twist”, and number of walls – either conducting or semi-conducting in their electrical behavior 34 Source: http://www.weizmann.ac.il/chemphys/kral/nano2.jpg Electric current varies by tube structure Multi-walled
35
Physical Properties Change: Melting Point of a Substance Melting Point (Microscopic Definition) – Temperature at which the atoms, ions, or molecules in a substance have enough energy to overcome the intermolecular forces that hold the them in a “fixed” position in a solid 35 Sources: http://puffernet.tripod.com/thermometer.jpg and image adapted from http://serc.carleton.edu/usingdata/nasaimages/index4.html In contact with 3 atoms In contact with 7 atoms Surface atoms require less energy to move because they are in contact with fewer atoms of the substance
36
Physical Properties Example: Substance’s Melting Point II At the macroscaleAt the nanoscale The majority of the atoms are… …almost all on the inside of the object …split between the inside and the surface of the object Changing an object’s size… …has a very small effect on the percentage of atoms on the surface …has a big effect on the percentage of atoms on the surface The melting point… …doesn’t depend on size… is lower for smaller particles 36
37
Size Dependant Properties Why do properties change? 37
38
Scale Changes Everything There are enormous scale differences in our universe! At different scales – Different forces dominate – Different models better explain phenomena 38
39
Scale Changes Everything II Four important ways in which nanoscale materials may differ from macroscale materials – Gravitational forces become negligible and electromagnetic forces dominate – Quantum mechanics is the model used to describe motion and energy instead of the classical mechanics model – Greater surface to volume ratios – Random molecular motion becomes more important 39
40
Dominance of Electromagnetic Forces Because the mass of nanoscale objects is so small, gravity becomes negligible 40 – Gravitational force is a function of mass and distance and is weak between (low-mass) nanosized particles – Electromagnetic force is a function of charge and distance is not affected by mass, so it can be very strong even when we have nanosized particles – The electromagnetic force between two protons is 10 36 times stronger than the gravitational force! Sources: http://www.physics.hku.hk/~nature/CD/regular_e/lectures/images/chap04/newtonlaw.jpg http://www.antonine-education.co.uk/Physics_AS/Module_1/Topic_5/em_force.jpg
41
Quantum Effects Classical mechanical models that we use to understand matter at the macroscale break down for… – The very small (nanoscale) – The very fast (near the speed of light) Quantum mechanics better describes phenomena that classical physics cannot, like… – The colors of nanogold – The probability (instead of certainty) of where an electron will be found 41 Macrogold Sources: http://www.phys.ufl.edu/~tschoy/photos/CherryBlossom/CherryBlossom.html http://www.nbi.dk/~pmhansen/gold_trap.ht; http://www.sharps-jewellers.co.uk/rings/images/bien-hccncsq5.jpg; Nanogold
42
Surface to Volume Ratio Increases As surface to volume ratio increases – A greater amount of a substance comes in contact with surrounding material – This results in better catalysts, since a greater proportion of the material is exposed for potential reaction 42 Source: http://www.uwgb.edu/dutchs/GRAPHIC0/GEOMORPH/SurfaceVol0.gif
43
Random Molecular Motion is Significant Tiny particles (like dust) move about randomly – At the macroscale, we barely see movement, or why it moves – At the nanoscale, the particle is moving wildly, batted about by smaller particles 43 Source: http://www.ap.stmarys.ca/demos/content/thermodynamics/brownian_motion/rand_path.gif Analogy – Imagine a huge (10 meter) balloon being batted about by the crowd in a stadium. From an airplane, you barely see movement or people hitting it; close up you see the balloon moving wildly.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.