Our primary research interest lies in finding simple and elegant ways
to control the structures of materials at different length scales precisely.
Multi-scale hierarchical structures are found abundantly in nature for
surprisingly different purposes. For example, the amazing climbing abilities
of geckos on different surfaces can be attributed to a hierarchical structure
on their food pads. Hierarchical structures on lotus leaf make the leaf
surface both superhydrophobic and self-cleaning. In another totally different
situation, Morpho butterflies show brilliant iridescent colors arising
from very delicate and hierarchical structures on their wing scales.
All those structures found in nature are formed by the so-called “bottom up” method, self assembly of nano-scale building blocks into functional macroscopic structures. Taking advantage of their best properties individually and putting them together in a synergic way is, however, not always an easy task for humankind. Our goal is to study and understand the fundamental principles of self- and guided- assembly of nano-“building blocks”, such as polymers, nanoparticles, cells, biomolecules, etc. Based on our understandings, we will then develop economic routes (by integrating both bottom-up and top-down methods) to fabricate organic-inorganic hybrid materials with both hierarchical structures and multiple functionalities. Those revolutionary materials will have impacts on the development of more efficient photovoltaics, photonic crystals, multi-functional and environmentally adaptive nanomotors, as well as biomedical diagnostic/therapeutic systems.
N. Wu and Y.C. Chiew, Multidensity integral equation theory for short diblock hard sphere-sticky hard sphere chains, Phys. Rev. E. 81, 041809 (2010).
N. Wu, M.E. Kavousanakis, and W.B. Russel, Coarsening in the electrohydrodynamic patterning of thin polymer films, Phys. Rev. E. 81, 026306 (2010).
N. Wu and W. B. Russel, Micro- and nano-patterns created via electrohydrodynamic instabilities, Nano Today 4, 180-192 (2009), invited review.
W. B. Russel, N. Wu, and W.N. Man, A generalized Hertzian model for the deformation and cracking of colloidal packings saturated with liquid, Langmuir 24, 1721-1730 (2008).
N. Wu, L.F. Pease, and W.B. Russel, Toward large-scale alignment of electrohydrodynamic patterning of Thin Polymer Films, Adv. Funct. Mater. 16, 1992-1999 (2006), featured on the cover of the issue.
N. Wu, L.F. Pease, and W.B. Russel, Electric-field induced thin polymer film patterns: weakly nonlinear and fully nonlinear evolution, Langmuir 21, 12290-12302 (2005).