Microfluidic ultramicroscale deposition and patterning of quantum dots

The ability to directly deposit materials in ultraminiaturized domains with nanoscale accuracy could play a central role in the realization of some forms of nanotechnology. In this report we demonstrate the direct deposition of quantum dots in patterns with ultramicroscale (1-15 microm) and nanoscale (<1 microm) features. Unlike bottom up approaches that require preconfigured patterning steps, this top down 'direct write' method should be amenable to the construction of a large variety of patterns and features essentially 'on the fly'. To accomplish the direct writing/deposition of quantum dots we used a system that integrates high resolution motion control with microfabricated fluid delivery cartridges. This process is termed FEMTO (fluidics enhanced molecular transfer operation). The methodology demonstrated here may be extended to surface patterning and deposition of a broad spectrum of other nanoscale materials and thereby create opportunities in a variety of fields ranging from microelectronics to bio/nanotechnology.