Self-Assemby of Sub-10 nm Particles


We are developing a predictive computational platform and an in situ characterization approach to understand the mechanisms of directed self-assembly (DSA) of sub-10 nm particles (SNP) into any desired pattern, and controlling it at interfaces with single particle resolution. DSA at multiphase interfaces are widely utilized for nanofabrication of novel devices in emerging fields such as nanosensing, nanoelectronics, and nanobiotechnology. Novel materials for future nanotechnology will have to self-assemble without intervension. In that regard, DSA will be very advantageous (see other movies below).

We are also looking at the kinetics of individual nanoparticles as they are trapped in the nanocavities. Top and side view of a tracer particle shown in blue in Movie 3 indicate the importance of the random motion as the nanoparticle clearly misses few nanocavities before it is ultimately trapped. Furthermore, the side view shows the preference of the tracer nanoparticle to come out of the trap, yet its way is blocked by other nanopartiles that have not been trapped. Overall, the tracer nanoparticle follows a resonant kinetics, exploring in and out of the nanocavity very frequently until it is eventually fixed in place by the receding contact line.

Movie 1 and 2. Top and side views of a coarse-grained molecular dynamics simulation of DSA of sub-10 nm gold particles (yellow) into a square lattice etched out from the substrate (gray). In the top view, fluid phase has been switched off for clarity. Trapped nanoparticles are shown in red. Developed by Zhen Luo, MolS Lab.

Movie 3. Top (right) and side (left) views of a coarse-grained molecular dynamics simulation of DSA of sub-10 nm particles, indicating a tracer sub-10 nm particle (blue) being trapped in a nanocavity. Developed by Zhen Luo, MolS Lab.