Microfluidic Control of the Internal Morphology in Nanofiber-Based Macroscopic Cables

摘要

Assemblies of nanofibers with macroscopic dimensions are utilized in a variety of fields, including the production of electronic and optical sensors and scaffolds for living tissues.A significant number of nanofiber assemblies are currently being generated using various bioorganic/synthetic nanofibers (e.g., carbon nanotubes (CNTs), DNA molecules, and protein fibrils). For integration of nanofibers into materials, macroscopic cables comprising assembled nanofibers have recently attracted much attention. These cables are typically produced by microfluidic elongational flow processes, and thus the nanofibers in the cable become oriented along the long axis. This anisotropic orientation provides a number of potential advantages including improvements in mechanical strength and directional control of cell growth and chemical synthesis. To expand on the advantages of the anisotropic properties of these macroscopic cables, control of the orientation of the nanofibers in a direction other than the long axis is also essential, because the physicochemical properties of assembled structures are strongly dependent on their internal morphology.119"211 However, because conventional fluidic approaches only focus on using the elongational flow, control of the internal morphology of the macroscopic cables has not been achieved. In this study, we demonstrate control over the internal morphology of macroscopic cables of assembled nanofibers.