Large-scale Assembly of Nanowire Powders:
In this project, we developed bulk processes for the large-scale assembly of nanowires into highly dense pellets. In addition to the consolidation of nanowires in a randomly oriented fashion into pellets, we have also accomplished consolidated of nanowires into pellets composed of oriented arrays of nanowires. Such simultaneous consolidation and orientation of nanowires is useful for studying anisotropic properties of large assemblies of nanowires. Furthermore, we have extended the processes for the assembly of nanowires by coupling it with phase transformation processes in nanowires to realize welded nanowire assemblies. Such welding not only made the nanowire assemblies robust, but also ensured the formation of oxide-free electrical conduction paths between the nanowire interfaces in the assembly. Illustrative pictographs of nanowire pellets obtained in our laboratory, along with the micrograph of assembled and welded nanowires, are provided below.