NANOTECHNOLOGY Flashcards
(24 cards)
- The engineering of functional systems at the molecular scale.
- It is a Hybrid Science combining Engineering, Chemistry and to a certain extent Biology.
- It deals with the creation of functional materials, devices, systems through control of matter or nanoscale.
- It placed the footprints in the field of energy, medicine, electronics, computing, security and materials.
NANOTECHNOLOGY
are the design, characterization, production and application of structures, devices and systems by controlling shape and size at nanometer scale.
Nanotechnologies
is the study of phenomena and manipulation of materials at atomic, molecular and macromolecular scales, where properties differ significantly from those at a larger scale.
Nanoscience
refers to the manipulation of matter on an atomic or subatomic scale
Nanotechnology
refers to a unit meaning one billionth or ten raised to negative nine
Nano
Father of Nanotechnology
Richard Feynman
dwarf means ?
Nanos
- Richard Feynman, an American Physicist discussed, “There’s Plenty of room at the Bottom”.
1959
- Mohamed Atalla and Dawon Kahng fabricated the first MOSFET (metal – oxide-semiconductor field-effect transistor) with a gate oxide thickness of 100nm, along with a gate length of 20μm
1960
- Norio Taniguchi, a Japanese scientist of Tokyo University of Science coined the term “nanotechnology” to describe semiconductor processes such as film deposition and ion beam milling exhibiting characteristic control on the order of a nanometer.
1974
- The invention of Scanning Tunneling Microscope, an instrument used for imaging surfaces at the atomic level. It was invented by Gerd Binnig and Heinrich Rohrer at IBM Zurich (Nobel Prize in Physics).
1981
- The discovery of fullerenes, an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to seven atoms.
1985
- The discovery of carbon nanotubes by Sumio Lijima
1991
– Publication of the book Engines of Creation: The Coming Era of Nanotechnology by Eric Dexler.
1986
- The discovery of 3nm MOSFET, the worlds ’smallest nanoelectronic device was created by Korean Researchers from the Korea Advanced Institute of Science and Technology and the National Nano Fab Center
2006
- In Mesopotamia, nanoparticles were used for creating a glittering effect on the surface of pots.
- In modern times, pottery from the middle Ages and Renaissance often retains a distinct gold- or copper-colored metallic glitter.
- In Rome, Lycurgus cup is made of a glass that changes colour when light gleamed through it.
- In pre-columbian Mayan City of Chichen Itza, a corrosion resistant azure pigment known as “ Maya Blue” contains nanopores to create an environmentally stable pigment.
- In Middle East, Damascus steel swords contain oriented nanoscale wire-and-tube-like structures
Early uses of Nanomaterials
- It’s hard to imagine just how small nanotechnology is. One nanometer is a billionth of a meter, or 10-9 of a meter. Here are a few illustrative examples:
o There are 25,400,000 nanometers in an inch
o A sheet of newspaper is about 100,000 nanometers thick
o On a comparative scale, if a marble were a nanometer, then one meter would be the size of the Earth.
Fundamental Concepts in Nanoscience and Nanotechnology
Different Approaches to Nanotechnology :
- Top-down
- Bottom-up
o Etching a block of material down to the desired shape
o Chips and processors
Top-down
o Building materials atom by atom - like lego
o Nanoparticles such as C60, carbon nanotubes, quantum dots
Bottom-up
Applications of Nanotechnology :
- Catalysts
o Envirox™ cerium oxide - Nanoremediation
o SAMMS technology to remove mercury - Paper
o photographic paper - Filters
o nanofibres - Toothpaste to remineralise teeth
- Food
- Packaging
- Paint
- Improved adhesion and anti-fungal qualities/anti-graffiti
- Clothes
- Non-staining and anti-radiation
- Batteries
- (Black & Decker) phosphate nanocrystal technology
- Cleaning products
- Protect drugs from being degraded in the body before they reach their target
- Enhances the absorption of drugs into tumors and into the cancerous cells themselves.
- Allows for better control over the timing and distribution of drugs to the tissue, making it easier for oncologists to assess how well they work.
- Prevent drugs from interacting with normal cells , thus avoiding side effects
Advantages of Nanotechnology
- Adverse health effects in humans from deliberate or accidental exposure
- Adverse effects on the environment from deliberate or accidental exposure
- Potentially explosive properties of nanostructures
- Very difficult to detect without sophisticated equipment
- Difficult to predict how particles will behave in the environment (dispersed/clumped)
- Small size may result in particles passing into the body more easily (inhalation, ingestion, absorption)
- May be more reactive due to surface area to volume ratio
- Potential to adsorb toxic chemicals
- Persistence - Longevity of particles in the environment and body are unknown
Disadvantages of Nanotechnology
- Longevity of particles in the environment and body are unknown
Persistence
