Nanostructured materials exhibit extraordinary optical, electrical, mechanical and chemical properties that enable novel devices with enhanced performance and functionality. Nanostructures are frequently utilized in numerous applications including photovoltaics, chemical and biological sensing, biotechnology, solid-state lighting, hydrogen production via photocatalytic water splitting and other uses. These various areas of nanotechnology demand nanofabrication techniques that are cost effective and practical while maintaining quality control and process flexibility. The nanofabrication techniques must also be scalable in order to be seamlessly applied to real-world applications beyond the laboratory. Despite progress having been made, a versatile nanofabrication technology that can meets all necessary requirements is lacking. This research will open up a new nanomanufacturing process pathway that can be applied to speed-up laboratory and pilot-scale device development and also be scaled-up for large-area, high-throughput product manufacturing. This research will make significant impacts on the fields of nanotechnology, nanomanufacturing, plasmonics, optoelectronics and nanophotonics. Plans are for graduate and undergraduate students from underrepresented groups to receive training, participate in this highly interdisciplinary research and conduct experiments in the new Washington Clean Energy Testbeds facility.
Nanoimprint lithography is a simple, low-cost, high-resolution and high-throughput nanofabrication technique with compatibility for large-scale roll-to-roll manufacturing. However, current roll-to-roll nanoimprint lithography processes are all based on either thermal or ultraviolet-based curing techniques that require either high temperature or special photopolymer resists. In addition, roller molds are typically made by time-consuming and costly fabrication processes. The research team aims to design and develop a new roll-to-roll nanoimprint lithography process using environmentally friendly polymer resists and a high-resolution composite belt mold. The research is accomplished through fundamental understanding of mechanics and fluid dynamics of mold cavity filling under solvent-assisted conditions to produce quality nanostructures on large area flexible substrates with high resolution and high throughput. Solvent-assisted nanoimprinting offers a low temperature and low pressure process, which eliminates issues resulting from thermal expansion variations between the mold, substrate and resist and reduces energy input costs while increasing processing speed. New composite elastomeric belt molds are easily and affordably replicated for rapid prototyping while providing high-resolution. The high quality nanostructures on flexible substrates are fabricated using this method and integrated in to novel flexible optoelectronic devices to demonstrate its capabilities.
