Proceeding of the 51st International Conference on Electron, Ion, and Photon Beam Technology & Nanofabrication, May 26-June 1, 2007, Denver CO: (2007).
Topographically directed, evaporation driven self-assembly (EDSA) of nanoparticles is a promising manufacturing technique that combines the control
of top-down lithography with the speed of bottom-up self-assembly. , We have developed a modeling methodology, using computational fluid dynamics (CFD),
for simulating the global regime of directed EDSA. The global regime considers the macro-scale distribution of the particles in the colloidal solution.
The distribution is determined by the forces exerted on the particles due to the fluid motion, which is driven by evaporation and influenced by pinning
of the contact line by lithographically defined surface features.We have simulated the evaporation-driven flows generated within a volume of fluid that
is changing in size under various pinning conditions. The shape of the fluid volume is determined from free surface simulations using energy minimization
techniques. We have used this methodology to predict the evolution of the particle concentration distribution and to provide useful information about the
time scales required to generate a sufficient concentration of nanoparticles near a pinning feature so that self-assembly will occur. The model is one part
of a hierarchical set of multi-level engineering models that can be used to study the details of directed self-assembly processes.
Center for Nanoscale Science and Technology
NIST is an agency of the U.S. Department of Commerce
Website Comments:epgwebmaster@nist.gov