This grant provides funding for a new nano-manufacturing method to form nanowires and complex nanopatterns. The method involves the controlled sintering (firing) of self-assembled arrays of ligand stabilized metal and ceramic nanoparticles. The aim is to establish a basic understanding of how (i) particle size, (ii) particle array configuration, (iii) particle composition (iv) substrate identity, and (v) ligand destabilization method affect the nature of the of the nanowire or nanopattern formed. Three basic nanoparticle types Au, Ag and g-Fe2O3, each fabricated with a well-defined range of different sizes (2-15nm), will be used as fundamental building blocks in this project. These constituents will then be self-assembled into single component raft and line structures, as well as some novel composite metamaterial structures. Experiments will involve in-situ observations of the sintering process in a transmission electron microscope as well as observations of the room temperature stability of the nanoparticle arrays.
The most successful approaches to nanoscale manipulation and patterning have been based on electron beam lithography and scanning probe microscopy techniques. Unfortunately these methods are relatively expensive, serial in nature, and are not readily applicable to mass production of nanopatterns and nanowires. If this approach is successful, it will create an ability to reproducibly manufacture such nanostructures on a larger scale by simple and inexpensive chemical methods and is therefore of great practical importance, especially if the promised potential benefits of nanotechnology are to be taken up by industry and exploited in the next generation of consumer electronics, chemical sensing devices and magnetic recording media. The new nanofabrication techniques under investigation in this program have the potential to fulfill these latter criteria provided that the sintering processes occurring between individual nanoparticles in these self-assembled arrays can be controlled and understood.
