Nano Technology

1. NanoTechnology here’s what it means: • Nano – one billionth. Something divided into a million bits then each bit divided into a thousand smaller bits. • Technology – building things. • Nanotechnology – building things from very tiny parts.

2. Nanotechnology is a ‘buzz’ word. There is lots of hype about it. But ….There is nothing fundamentally new about making things from tiny parts. It has been happening in nature ever since the universe began:

3. living things are made from cells.

4. and all substances are made from atoms.

5. What’s new is the technology part. Through science we understand much about how tiny objects ‘work’:about atoms & molecules and cells. Now we can start to copy what happens in nature and to make new things using these methods.

6. In nature objects of tiny size are formed all the time. Tiny objects, atoms, molecules, cells, join together to make larger and more complex things. The natural world around us is made of a vast number of interacting parts, building up in size from very tiny to very large.

7. Until recently our crafts and technologies have been able to work only with objects that have sizes on the human scale – from hundreds of metres to a fraction of a millimetre. Though science & technology humans now have the ability to manipulate tiny sizedobjects – smaller than the parts in a living cell. Even as small as individual atoms.

8. Picture source: cnx.org/content/m14353/latest/ Individual atoms placed with Scanning Tunnelling Microscope (STM)

9. Iron atoms on copper – formed with Scanning Tunnelling Microscope (STM) Image source: http://www.cite-sciences.fr/english/ala_cite/exhibitions/nanotechnologies/images/diapo01/04-stm11.jpg

10. Nanotechnology is the ability to work with objects on the nanoscale. We can work with these tiny objects in many different ways. Before lookingat these in more detail we will try to get an idea of the size of the objects which exist in the nano-world.

11. A journey from the everyday world to the nano-world. 100 m 10-1 m 10-2 m10-3 m 10-4 m 1 metre 1 centimetre 1 millimetre 10-5 m 10-6 m 10-7 m10-8 m 10-9 m 10-10 m 1 micrometre 1 nanometre

12. A photograph about 1 metre across 100 metre

13. A photograph about 10 cm across 10-1 metre

14. A photograph about 1 cm across 10-2 metre

15. A photograph through light microscope about 1 mm across 10-3 metre

16. A photograph through light microscope about 0.1 mm across 10-4 metre

17. A photograph through light microscope about 0.01 mm across 10-5 metre

18. Electron microscope image about 0.001 mm across 10-6 metre

19. Electron microscope image about 0.0001 mm across 10-7 metre

20. Computer generated image about 0.00001 mm across 10-9 metre

21. Computer generated image about 0.000001 mm across 10-9 metre

22. Computer generated diagram about 0.0000001 mm across 10-10 metre

23. Ellora rock cut temple, India. Great pyramid, Egypt. In our everyday technologies we have different approaches to making things. Here are two examples from the (ancient) building industry. We can start with large objects and work down, by removing material, until we get the shape we want. We can start with small objects and work up, by adding material, until we get the shape we want.

24. We sometimes reshape material – like a potter. We sometimes work away a material – like a sculptor. We sometimes combine materials – like house builder.

25. Temple hewn from solid rock. Ellora caves, central India

26. Pyramid built from individual blocks of stone. Egypt

27. Nanotechnology also means working in many ways: • reshaping materials • carving smaller parts from larger ones • combining different materials • building large objects from smaller units • All at the nano scale – with things about a thousand millionth of a metre in size.

28. Some simple existing applications of nanotechnology: Sunscreenhttp://www.oxonica.com/optisol.htm Self cleaning windowshttp://www.chippingsodburyglass.co.uk/selfclean.htm Catalyst for diesel engines http://www.cerulean-international.com/products.htm Nanodiamondshttp://www.plasmachem.com All these are based just on the small size of the particles.

29. Nano crystals of titanium dioxide absorb ultra violet radiation but don’t affect visible light. Larger particles in ordinary sunscreen reflect visible light and so appear white. As the nano crystals are much smaller than the wavelength of visible light that light passes through the nano layer – it is transparent. So we have sunscreen which is invisible but it more effective at blocking uv than regular sunscreen.

30. Self cleaning glass has a nanolayer of titanium dioxide coating on the surface. This acts in two ways: First, it is photocatalytic: UV rays, abundant on even the cloudiest of days, cause the glass to react chemically with dirt and organic deposits, breaking them down and loosening them from the surface of the glass. Secondly, it is hydrophilic: it attracts water, which slides down and off the surface of the glass without forming into separate droplets. This ensures that loose particles of dust and dirt are easily washed off during normal rainy weather.

31. Envirox™ fuel additive is a scientifically and commercially proven diesel fuel combustion improver which reduces fuel consumption and also reduces harmful exhaust emissions. It is based on the use of cerium oxide nanoparticles which are a catalyst for the burning of carbon . Any carbon particles left from the diesel fuel burn up at lower temperature. The exhaust is cleaner and more energy is obtained – which lowers fuel consumption

32. Nano sized diamonds with an average diameter of 4 nano-metre, have many uses including polishing of: • Lapping and polishing applications • Nickel Plated Rigid Memory Disk • Al-Rigid Memory Disk Substrate • Polycarbonate and CR-39 Eyeglass Lenses • Miniature and Precision Ball Bearings • Optical and Laser Optical Components • Orthopedic Prostheses • Precious Stones • Honing Microtome Knives • Stainless Steel Sheet • Metallic Mirrors and Precision Metal Polishing • Acrylic Sheet, Aircraft Windows and Canopies • Contact Lenses • Superhard and Soft Nanoabrasives • Polishing of PC Hard Disc

33. More advanced nano devices in use or being developed: nanosensors for medical use DNA Chiphttp://www.plasmachem.com Bio-assay via Raman scattering:http://www.oxonica.com/biodiag2.htm Fluorescent nanocrystals for medical diagnostics:http://www.oxonica.com/biodiag1.htm Carbon nanotubes to monitor changes in breathinghttp://www.nature.com/news/2004/041108//full/041108-18.html

34. Some other nanotechnology applications: Lotus leaf effect Gecko tape (van der Waals forces controlled ! ) etc.

35. Hydrophobic surfaces – based on “Lotus leaf principle”

36. Some existing applications of lotus effect surface treatment. Stain resistant clothing from “NanoTex” fabrics

37. Gecko Tape.

38. Production of color by precise control of nanoscale structure – as in a butterfly wing.

39. “Quantum Dots” - CdSe of precisely controlled particle size. CdSe is a semiconductor and restricting the size of the particles to nano dimensions also confines the conduction band electrons. The fluorescent wavelength can be precisely controlled. This has gone from lab discovery to commercial production in about a decade.

40. Another type of Nanotechnology: modifying natural nanoscale systems. Modifying DNA:● Making artificial genes● Creating new letters for genetic alphabet (to add to natural CTGA) Making a “minimum living organism”:Removing genes from a cell, one by one, to find the smallest set of genes with which the cell can still live. Creating a living cell entirely from non living starting materials

41. More complex systems: Nano-machines DNA replication is a natural “machine” at the nanoscale. The DNA double helix is unwound, then the CTGA bases in each strand are paired with their complements to form two new double helix lengths of DNA – each an exact copy of the original. Movies of DNA replicationnature’s nanomachinery (Internet link required )

42. Inorganic machines. Nanoscale machines can be made that are not based on the chemicals in living things. They might be copies of large scale machines such as electric motors and contain familiar parts such as roller bearings. Nothing like this exists in nature. Materials built from small units like this might be very useful. Living cells in animals and plants have parts that have evolved to extract energy (from sunlight, from glucose etc) and essentially just build new cells. Imagine copying the complexity of organisms but replacing the living cells with nano scale motors, gears etc and with energy extracted from sunlight, or heat or a suitable fuel, and designed to produce almost anything we can imagine rather than just copies of themselves. Building atom by atom opens enormous possibilities.

43. Many of these parts have been designed Some have been produced:

44. This might seem very far fetched, but we know that even just the arrangement of atoms has dramatic effects. Carbon atoms arranged one way form diamond Arranged another way they form graphite And in another arrangement they form charcoal

45. If we use more than one type of atom the possibilities are increased. We know that living things are made up of many interacting tiny parts, yet they are made of a limited range of atoms, and have just a few basic ways of obtaining energy. Its hard to even imagine what might be made when we assemble things atom by atom, without any of the limitations that we see in living systems.

46. Nanotechnology means any technology we devise that manipulates things about a billionth of a metre in size. There are lots of ways of doing this. Some practical applications already exist, but we are just at the beginning of the nanotechnology age and we can’t even imagine all the possible ways nanotechnology will be used - even in the near future.

47. Animations of imagined nanotechnology factory (broadband connection needed for movies, slide sets over dial-up connections) Google Movie of nanotechnology production