Nanotechnology Study Notes

Definition: The prefix "nano" derives from the Greek word meaning "dwarf." In scientific terms, it refers to a scale of 10^{-9}, or one billionth of something.
- Example of size: A virus is approximately 100 nm in size.
Range: Nanotechnology typically pertains to materials and technologies within the size range of 0.1 to 100 nm. Anything larger is classified under microtechnology.

Definition: It involves the creation and manipulation of materials and structures that are smaller than 100 nm.

Definition: A combination of biotechnology and nanotechnology aimed at designing, characterizing, producing, and applying structures, devices, and systems by manipulating shape and size at the nanometer scale.

Hierarchical Size Representation:
- Humans (1.75–2.5 m) → 100 m (1 meter)
- Fly (~1 cm) → 10^{-1} m
- E. Coli Bacteria (~2 μm) → 10^{-6} m
- Nano shell (100 nm) → 10^{-7} m
- DNA (2 nm) → 10^{-9} m
- Carbon nanotube: 1.3 nm → 1 nm
- Bucky ball: 1 nm
- Virus (50 nm) → 10^{-8} m

Examples of sizes:
- Water molecule: ~0.3 nm
- Glucose molecule: ~1 nm
- Antibodies: ~10 nm
- Viruses: ~50-300 nm
- Bacteria: ~1–10 μm (10^3-10^6 nm)
- Cancer cells: ~10-100 μm (10^7-10^8 nm)

1959: Richard Feyman issued the statement "There is plenty of room at the bottom," proposing a process to manipulate individual atoms and molecules.
1965: Gordon Moore predicted the doubling of transistor counts on microchips approximately every 18 months, consequentially leading to further advancements in technology, including the Pentium 4.
1974: N. Taniguchi defined nanotechnology, emphasizing the manipulation of materials at the molecular or atomic level.
1986: Eric Drexler further popularized nanotechnology and its significance.
1980s: Significant progress was made following the invention of Scanning Tunneling Microscope (STM) and Atomic Force Microscope (AFM).

Ralph Merkle: Nanotechnology theorist.
Robert Feritas: Theorist in nanomedicine.
Sumio Iijima: Known for discovering carbon nanotubes.
Richard Smalley, Harry Kroto: Discovered Buckminsterfullerene.
Gerd Binnig, Heinrich Rohrer: Inventors of Scanning Tunneling Microscope.
Phaedon Avouris: Developed the first electronic device using carbon nanotubes.
David Tomanek: Fundamental properties of nanostructured materials.

Automotive Industry:
- Lightweight construction (tires, coatings).
- Catalysts and chemical sensors.
Electronic Industry:
- Data memory (MRAM, GMR-HD).
- Displays (OLED, FED).
Construction:
- Enhanced materials (thermal insulation, flame retardants).
Medicine:
- Drug delivery systems, prostheses, antimicrobial agents.

Materials: Lightweight for military use.
Quantum cryptography: Uses properties of quantum mechanics for secure communications.
Chemical sensors: Detecting single molecules among millions.
Nanometals: Enhanced reactivity of nano-sized metals leading to stronger explosives.

Advanced data storage and memory systems.
- Increased frequencies and capabilities in electronics.
- Smart materials for flexible applications.
- Innovations in healthcare, such as replacement organs and biosensor technology.

Differentiating Features: Enhanced properties at the nano-scale due to increased surface area and quantum effects.
Applications: Novel electrical, catalytic, magnetic, mechanical, thermal, or imaging features for diverse uses.
Types of Nanomaterials:
- Carbon-based materials: Fullerenes, nanotubes.
- Metal-based materials: Nanoshells, nanoparticles.
- Dendrimers and nanoparticles have significant potential in various applications.

Definition: Carbon allotropes forming hollow spheres, ellipsoids, or tubes; including buckyballs and carbon nanotubes.
Discovery: By Robert Curl, Harold Kroto, and Richard Smalley at the University of Sussex in 1985.
- Nomination for Nobel prize based on its unique and stable structure.
Properties:
- Physical dimensions: 7-15 Angstroms for fullerenes; stability against high temperatures.
- Solubility: Fullerenes are sparingly soluble in several solvents such as toluene.
Applications:
- Used as sponges for cleaning chemicals, and in electronics for improving circuit performance.

Definition: Cylindrical structures of carbon atoms that have remarkable properties, including high tensile strength and electrical conductivity.
Applications: Ideal for use in electronics, clothing, medical devices, and fuel cells due to their unique structure.

Definition: Nanoparticles with a dielectric core and a thin metallic shell; tunable optical properties based on core-shell configurations.
Properties and Applications: Strong optical absorption, important for medical therapies, especially targeted drug delivery systems.

Overview: Complex, branched macromolecules with precise structures and functional properties.
Synthesis: Defined by controlled growth systems—divergent and convergent methods.
Applications: Include drug delivery systems, diagnostics, and as carriers in gene therapy.

Definition: Semiconductor nanoparticles with quantized energy states leading to novel optical properties.
Discovery and Properties: Change in properties based on size, enabling different light emissions.
Applications: Ideal for biological tagging, photonic devices, and detecting radiations.

Definition: Design and manufacturing of nanometer-scale devices; relevant for advanced electronics and medical applications.
Approaches:
- Top-down: Reducing dimensions layer by layer (like traditional microfabrication).
- Bottom-up: Assembling atoms or molecules into structures through self-assembly.
Lithographic Techniques:
- Photolithography, electron-beam lithography, x-ray lithography, and soft lithography for creating nanostructures.

Overview: Developed in 1981 by Gerd Binnig and Heinrich Rohrer, allowing for imaging surfaces at the atomic level via quantum tunneling.
Applications: Analyzing non-conductive surfaces and biological samples by scanning a sharp tip across the surface while maintaining constant current.