Multi-scale Nanotextured Surfaces by Tribo-Electrohydrodynamic Lithography for Controlled Drug Release

Iowa State University, Ames IA

Investigators

Abstract

This grant supports research that creates a disruptive nanoscale manufacturing technology for rapid fabrication of multiscale nanostructures, promotes scientific progress, and advances national prosperity and health. Realization of multiscale nanostructures with existing nanofabrication methods is a challenging endeavor. For example, electron beam lithography is limited to very small scale structures, whereas nanoimprint lithography requires very elaborate master patterns. This project explores the technique of nanoscale replica molding as a rapid and inexpensive way to form intricate master nanostructures from large-area templates. The accompanying formation of surface "tribocharges" are utilized to fabricate multiscale nanostructures with sub-100 nanometer sub-structures. By this means, nanotextured surfaces having biomedical uses are possible. With elaborate plans to stimulate nanomanufacturing and bring the resulting surface-patterned biomedical devices to the people with heart-disease, this work aligns well with the nation's efforts to boost manufacturing in the U.S. and to innovate biomedical technologies. This research involves several disciplines including manufacturing, surface physics, electromagnetics, and materials science. This multi-disciplinary approach helps broaden the participation of women and underrepresented minorities in research and positively impacts engineering education. This project enables highly controlled nanopatterning of tribocharge distribution on polymer substrates through nanoscale replica molding and provides a deeper understanding of the underlying mechanisms for generation and patterning of tribocharges. Investigations of the tribocharge's longevity, spatial stability, and nanotexture dependence are performed. The nanopatterned tribocharges are then used as the source of nanoscale-modulated electric fields for electrohydrodynamic lithography, by which 3-level hierarchical multiscale nanostructures are fabricated. The target nanostructures include nanoscale volcanoes with sub-100 nm-scale nanocraters and multiple-period nanostructure arrays. The drug release from such multiscale nanotextures made of biocompatible polymers are also studied for emerging applications such as stents for cardiac therapies. The fundamental research outcomes widen the knowledge required for the realization of multiscale nanostructures in general, eventually enabling the synthesis of new materials and structures with novel functionalities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.