Steering nanofibers: An integrative approach to bio-inspired fiber fabrication and assembly

• Published in: Nano today 2012-02, Vol.7 (1), p.35-52
• Main Authors: Grinthal, A., Kang, S.H., Epstein, A.K, Aizenberg, M., Khan, M., Aizenberg, J.
• Format: Article
• Language: English
• Subjects: Bio-inspired; Chirality; Dynamic and responsive surface; Fibrous surface; Hierarchical architectures; Nanofabrication; Nanofibers; Nanoscale mechanics; Self-assembly; Surface chemistry
• ISSN: 1748-0132; 1878-044X
• DOI: 10.1016/j.nantod.2011.12.005

[Display omitted] ► Integrative approach to creating fibrous surfaces with multiscale complexity and dynamic behavior. ► Low-cost benchtop techniques to generate libraries of nanofiber arrays with fine-tuned parameters. ► Program fiber arrays to self-assemble into complex, chiral, hierarchical architectures. ► Encode reversible, responsive behavior through rationally chosen surface chemistry. As seen throughout the natural world, nanoscale fibers exhibit a unique combination of mechanical and surface properties that enable them to wind and bend around each other into an immense diversity of complex forms. In this review, we discuss how this versatility can be harnessed to transform a simple array of anchored nanofibers into a variety of complex, hierarchically organized dynamic functional surfaces. We describe a set of recently developed benchtop techniques that provide a straightforward way to generate libraries of fibrous surfaces with a wide range of finely tuned, nearly arbitrary geometric, mechanical, material, and surface characteristics starting from a single master array. These simple systematic controls can be used to program the fibers to bundle together, twist around each other into chiral swirls, and assemble into patterned arrays of complex hierarchical architectures. The delicate balance between fiber elasticity and surface adhesion plays a critical role in determining the shape, chirality, and higher order of the assembled structures, as does the dynamic evolution of the geometric, mechanical, and surface parameters throughout the assembly process. Hierarchical assembly can also be programmed to run backwards, enabling a wide range of reversible, responsive behaviors to be encoded through rationally chosen surface chemistry. These strategies provide a foundation for designing a vast assortment of functional surfaces with anti-fouling, adhesive, optical, water and ice repellent, memory storage, microfluidic, capture and release, and many more capabilities with the structural and dynamic sophistication of their biological counterparts.