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Flashcards 28 Flashcards
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Language Deutsch
Level Secondary School
Created / Updated 15.05.2022 / 15.05.2022
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Learning objectives

The aim of the lecture "Nanotechnology" is to give you an insight into the "concepts", materials, structures, applications, market, opportunities, swiss industries…. and risks of nanotechnology. You should get to know some experimental processes that are important for nanotechnology. Through the lecture, you should be able to form your own opinion on the opportunities and risks of nanotechnology and discuss about it.

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What is nano?

Nano (Latin nános), meaning "dwarf“ 1 nm → 10^-9 m

1 nm is to an orange what an orange is to the Earth

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Nanotechnology: some definitions

The American Heritage dictionary: The science and technology of nanoscale devices and materials, such as electronic circuits, constructed using single atoms and molecules. 

NASA: By definition, nanotechnology, or “nano”: is the creation of functional materials, devices, and systems through control and manipulation of matter on the nanometer length scale (1-100 nanometers). For the sake of comparison, an ordinary sheet of paper is 100,000 nanometers thick. At this scale, engineers have the ability to exploit novel phenomena and material properties, be they physical, chemical, biological, mechanical, or electrical.

Wikipedia: is the use of matter on an atomic, molecular, and supramolecular scale for industrial purposes. The earliest, widespread description of nanotechnology referred to the particular technological goal of precisely manipulating atoms and molecules for fabrication of macroscale products, also now referred to as molecular nanotechnology. A more generalized description of nanotechnology was subsequently established by the National Nanotechnology Initiative, which defined nanotechnology as the manipulation of matter with at least one dimension sized from 1 to 100 nanometers. This definition reflects the fact that quantum mechanical effects are important at this quantum-realm scale, and so the definition shifted from a particular technological goal to a research category inclusive of all types of research and technologies that deal with the special properties of matter which occur below the given size threshold.

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The birth of nanotechnology:

1959: Richard Feynman “There is plenty of room at the bottom”

1974: Norio Taniguchi Invents the term “nanotechnology” It mainly consists of the processing of, separation, consolidation, and deformation of materials by one atom or one molecule.

80s: Kim Eric Drexler Promoted the technological importance of nanoscale phenomena and devices Book: Engines of Creation: The coming Era of Nanotechnology

1982: Invention of the STM --> G. Binnig & H. Rohrer Nobel Prize 1986

1985: Discovery of fullerenes --> Smalley, Curl & Croto

1991: Discovery of carbon nanotubes --> S. Ijima

1997: First electronic molecular switch --> M Reed & J. M. Tour

 

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What nature teaches us: biomimetics

Lotus effect:The leaves of the lotus flower are superhydrophobic due to the micro and nanostructures of their leaves.

- Self cleaning: applications in textiles, self-cleaning glasses, protection of electronic equipment, roof tiles, exterior paints…

Impressive adhesion to any kind of surface thanks to their branched hairs (“setae”) that can turn stickness on and off

- Reversible adhesives, dynamic climbing in any kind of wall

- Colors change depending on the angle at which you look at the surface (so called iridescence)

 Different thicknesses, soap bubbles, can create iridescence. Nano and micro features, as in the blue Morpho butterfly, also cause iridescence.

 

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But not only in nature… in history also

- Colorful nanoparticles 

The key of Damascus sabres: Sabres from Damascus, made out of wootz have a microstructure of nm‐ sized tubes. The legendary Damascus sabres that Muslims used during the European warriors in the Cursades became famous: strong, flexible and incredibly sharp… Unluckily, the recipe for making them was lost in the XVIII century

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Industrial Applications: Superhydrophobic surfaces

Superhydrophobic surfaces are demanded form different markets

▶ food packaging ▶ painting ▶ architecture ▶ aircrafts

Requirements: 1. Large intrisic CA (hydrophobic material) 2. Hierarchical structure 

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Industrialization approach: R2R Hot embossing technique

Polymer nanostructuring Heating and cooling an dstructure sizes represents limitation Thermal nanoimprint lithography with arrays dimension down to 50nm