What is “Nano-scale Science and Technology”?

1. What is “Nano-scale Science and Technology”? Yonhua Tzeng, Professor Electrical and Computer Engineering Auburn University, Alabama USA July 7, 2003

2. What is “Nanotechnology”? The Earth X 10-8 Soccer Ball X 10-8 STM Image of C60 STM image of a carbon nanotube End Cap http://www.wtec.org/loyola/nano/IWGN.Public.Brochure/IWGN.Nanotechnology.Brochure.pdf

3. http://dynamo.ecn.purdue.edu/~janes/whats_nano.htm

4. http://dynamo.ecn.purdue.edu/~janes/whats_nano.htm

5. Nanoparticles have been used in our daily life. • Carbon black ( a nanoscale carbon) is used for writing and painting and is added to rubber to make tires more wear resistance. • Nano phosphors in CRTs display colors. • Polishing compounds for smoothing silicon wafers include nanoscale alumina and silica, etc. • Hard disks in our computers contain nanoscale iron oxide magnetic particles. • Nanoscale zinc oxide and titania block UV light for sunscreens. • Nanoscale platinum particles are critical to the operation of catalytic converters. • Metallic nanoparticles make stained glass and Greek vase colorful. • Nanoscale thin films have also been the heart of our silicon chips for our computers, digital cameras, and photonic devices for quite a while.

6. Commercial TiO2 Nanoparticles All TiNano 40 Series products are in the 30-50 nm primary particle size range. Surface treated products exhibit very littlecrystal growth or change of phase when held in an oxidizing atmosphere at 800º C for over 100 hours. Altium™ TiNano 40 Series slurry products are dispersed to primary crystallites in aqueous media and exhibit specific surface areas (BET) of 40-60 m²/g. The slurry product offers the advantage of requiring no dispersion, and also eliminates the handling of fine powders. A spray-dried product is also available that consists of readily dispersable agglomerates of primary particles. http://adserv.internetfuel.com/cgi-bin/omnidirect.cgi?SID=23&PID=2&LID=10&OSDELAY=10

7. Atoms, Molecules, And Nano-meter Sized Particles Have Been Around For A Long,Long Time. What is new? What makes it a promising technology? What is it good for?

8. http://dynamo.ecn.purdue.edu/~janes/whats_nano.htm

9. Small, of course! STM probe images of Fe atoms on Cu from IBM Almaden Research Lab http://www.almaden.ibm.com/vis/stm/atomo.html http://www-inst.eecs.berkeley.edu/~ee143/f2002/Lectures/Lec_28.pdf

10. How small? Atomic and Molecular Scales! http://cache.techtv.com/binaries/2002/smallgear.mpg http://cache.techtv.com/binaries/2002/gearandshaft.mpg

11. Definition of Nanotechnology (i): • The following is excerpted from the National Nanotechnology Initiative: The Initiative and its Implementation Plan (http://www.nano.gov/nni2.htm) • The essence of nanotechnology is the ability to • work at the molecular level, atom by atom, to createlarge structures with fundamentally new molecular organization. Compared to the behavior of isolated molecules of about 1 nm (10 -9 m) or of bulk materials, • behavior of structural features in the range of about 10 -9 to 10 -7 m (1 to 100 nm - a typical dimension of 10 nm is 1,000 times smaller than the diameter of a human hair) exhibit important changes. Nanotechnology is concerned with materials and systems whose structures and components exhibit • novel and significantly improved physical, chemical, and biological properties, phenomena, and processes due to their nanoscale size.

12. Definition of Nanotechnology (ii): • The goal is to exploit these properties by • gaining control of structures and devices at atomic, molecular, and supramolecular levels and to learn to efficiently • manufacture and use these devices. Maintaining the • stability of interfaces and the • integration of these "nanostructures" at micron-length and macroscopic scales are all keys to success.

13. Definition of Nanotechnology (iii): • New behavior at the nanoscale is not necessarily predictable from that observed at large size scales. • The most important changes in behavior are caused not by the order of magnitude size reduction, but by newly observed phenomena intrinsic to or becoming predominant at the nanoscale. • These phenomena include size confinement, predominance of interfacial phenomena and quantum mechanics.

14. Definition of Nanotechnology (iv): • Once it becomes possible to • control feature size, it will also become possible to • enhance material properties and device functions beyond what we currently know how to do or even consider as feasible. • Being able to • reduce the dimensions of structures down to the nanoscale leads to the unique properties of carbon nanotubes, quantum wires and dots, thin films, DNA-based structures, and laser emitters. • Such new forms of materials and devices herald a • revolutionary age for science and technology, • provided we can discover and fully utilize the underlying principles.

15. Fundamental Principles Nanoscale Phenomena • Size effects • Confinement • Interfacial phenomena • Quantum mechanics • Biological systems

16. Size and Shapes: High aspect ratio of carbon nanotubes and Metal-atom filled Nanotubes Nanostructure Science : R&D Status and Trends in Nanoparticles, Nanostructured Materials, and Nanodevices (1998) http://www.wtec.org/loyola/pdf/nano.pdfand Technology

17. Molecular Structural Effects Properties of the Carbon Nanotubes http://www.bit.ac.at/nmp/AT_F_Kooperation/02_hammel.pdf

18. sy ASTM Size Effects Image from Prof. Prorok, Auburn University

19. Confinement Effects http://www.physik.uni-wuerzburg.de/TEP/Website/events/ESS_2001/Reithmaier/EU_summer_2001_talk2.pdf

20. Confinement Effects http://www.unipress.waw.pl/CE/Network/network.pdf