Nanofabrication Technologies

1. Nanofabrication Technologies

3. 1 nm = 10-3 m = 10-6 mm = 10-9 m

4. Entities include structures, films, coatings, dots, lines, tubes, and systems

5. Nanoscience – the field of scientific study that is concerned with objects in the 1 to 100 nm range

7. Originally named buckministerfullerene, after R. Buckminister Fuller, designer of the geodesic dome (shortened to fullerene)

9. 12 pentagonal faces

11. Depending on structure and diameter, can have conducting or semiconducting properties

12. Conductivity superior to copper due to fewer defects that increase electrical resistance

13. Thus, high currents do not increase temperature as in metals

16. Carbon arc techniques

18. Graphite workpiece is placed in quartz tube filled with argon and heated to 1200°C

19. A pulsed laser beam is focused on surface, causing carbon atoms to evaporate from the bulk graphite

21. 25 V is applied across the electrodes, causing carbon atoms to be ejected from positive electrode and carried to negative electrode where they form nanotubes

22. If no catalyst – multi-walled nanotubes form

24. Gas is heated to 1100°C, causing it to decompose and release carbon atoms

25. Atoms condense on cool substrate to form nanotubes

26. Substrate surface may contain metallic traces that act as nucleation sites for nanotubes