nanotimes News in Brief
Nanostructures // A New Production Way
esearchers at Massachusetts Institute of Tech- nology, Cambridge, USA, and Singapore-MIT
Alliance for Research and Technology (SMART) Cen- tre, Singapore, have found a way to produce more complicated structures by using a blend of current “top-down” and “bottom-up” approaches.
The new method is a hybrid in which the self- assembled array is produced directly on a substrate material, performing the function of a mask for the lithography process. The individual nanoparticles that assemble on the surface each act as tiny lenses, focu- sing the beam into an intensity pattern determined by their arrangement on the surface. The method, the authors say in their paper, “can be implemented as a novel technique to fabricate complex 3-D nano- structures in all fields of nanoscale research.”
“We took a chemist‘s method and added in a flavor of engineering,” researcher C.-H. Chang says.
Depending on the shapes and arrangements of the tiny glass beads they use for the self-assembly part of the process, it is possible to create a great variety of structures, “from holes to higher-density posts, rings, flowery structures, all using the exact same system,” Chang says. “It‘s a very simple way to make 3-D nanostructures, and probably the cheapest way right now. You can use it for many things.”
11-06/07 :: June/July 2011
The new 3D nanofabrication method makes it possible to manufacture complex multi-layered solids all in one step. In this example, seen in these Scanning Electron Micro- scope images, a view from above (at top) shows alterna- ting layers containing round holes and long bars. As seen from the side (lower image), the alternating shapes repeat
through several layers. © Chih-Hao Chang
C.-H. Chang, L. Tian, W. R. Hesse, H. Gao, H. J. Choi, J.-G. Kim, M. Siddiqui, and G. Barbastathis: From Two- Dimensional Colloidal Self-Assembly to Three-Dimensi- onal Nanolithography, In: NANO Letters, Vol. 11(2011), Issue 6, June 8, 2011, Pages 2533-2537, DOI:10.1021/ nl2011824: