10-07/08 :: July/August 2010
The team around Shlomo Magdassi discovered that inkjet printed patterns, composed of silver nanopar- ticles, can undergo a spontaneous aggregation-coale- scence process, which results in sintering individual nanoparticles into a continuous structure without any heating. This process is triggered by surface charge neutralization, which occurs on plastic substrates and even on paper by using simple, low cost charge neutralizing agents. The resulting high conductivity, 20% of that for bulk silver enables fabrication various devices, for example, a flexible plastic electrolumine- scent ink-jet printed device, without any heating.
The Hebrew University of Jerusalem, IL http://chem.ch.huji.ac.il/applsci/ac/facult.htm
X-section of Si nanowires formed by BCP pattern transfer to the Si layer of an SOI substrate. © M. A. Morris, Richard A. Farrell and Justin D. Holmes/ Trinity College Dublin
12” substrates. Such accuracy in BCP systems can only be achieved by means of ‘directing’ the struc- ture because films on simple substrates have limited periodicity and demonstrate ‘finger-print” patterns. Structural alignment is achieved by two principal me- thods, chemical and graphoepitaxial patterning.
Prof. M. A. Morris from Department of Chemistry, University College Cork and Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin, Ireland, presented in the session “Polymer Nanotech: Copolymer surfaces: Applications” his work and recent data on how self-organising – this is the more correct description since the systems show well resolved order-disorder transitions – block polymer (BCP) systems can be used to create nanocircuitry elements (“Scaling Beyond Lithographic Limits – Polymer Self-Assembly Mediated Sub-20 nm FET devices”, with research colleagues Richard A. Farrell and Justin D. Holmes).
The most challenging aspects of using self-organisa- tion for nanodevices fabrication are probably asso- ciated with periodicity and positioning, according to Prof. Morris. Conventional lithography achieves the required placement accuracy within the pattern over
The biggest challenge towards the use of nanopat- terns into real devices for circuit development is generating highly regular periodic structures over large surface areas and these nanopatterns must be effectively defect free. In graphoepitaxy, this is only possible through the control of chemistries at the base of the channel, the sidewalls and the mesas.
M. Morris, University College Cork, Ireland, IE, Phone: +353 214902180. http://www.ucc.ie/en/chemistry/morris/
In the session “Electronic Applications of Carbon Nanotubes” D.S. Lashmore, B. White, C. Lom- bard from Nanocomp Technologies spoke about “Carbon Nanotube Light Weight Electrical Con- ductors”. In their presentation properties of coaxial