Final Report Summary - DAPOMAN (Directed Assembly of Polymeric Materials Nanofabrication)
The work carried out in DAPOMAN focused on investigating the novel use and the potential applications of self-assembly principles and self-assembling materials in the design and manufacture of complex, nanoscale structures.
The key driving idea is to use self-assembling materials to create regular structures at the nanoscale which then serve as templates or patterns for the fabrication of nanodevices in the area of the semiconductors, nonlinear optical materials, nanostructured and graded materials.
The collaboration between the visiting scientist and the host institution focused mainly on the development of a first-principles approach to the modeling of self-assembly in complex materials, mainly homo- and co-polymers,. This approach is based on multiscale, hierarchically organized modeling methods that range from atomistic Molecular Dynamics (MD), to coarse-grained Monte Carlo (MC).
This suite of models were directly tested and applied to a wide variety of systems of quite different nature in order to assess their flexibility and reliability. In particular, two families of materials were addressed:
* self-assembly of thin copolymer films on nanoscale patterned surfaces (basically two-dimensional systems)
* self-assembly of hard-sphere systems, including both monomeric (single spheres), and polymeric ones (linear chains of spheres).
The key result achieved in the reporting period is that the suite of hierarchical methods, each operating at different spatial and temporal scales can successfully predict the expected or experimentally observed morphologies at the nanoscale level.
Furthermore, it has also been able to predict novel, entirely unexpected self-assembling morphologies. Prominent among these unexpected results is the finding that materials with a molecular structure of linear chains of hard spheres can spontaneously self-assemble in almost perfect random stackings of hexagonal layers. This discovery disproves a long-standing conjecture that connectivity suppresses entropic crystallization and opens the door to new methods of self-assembly which have not been explored up to now.
The achieved final results have major potential for application on two fronts:
* The development of resists using the DAPOMAN methodology based on self-assembling materials for nanolithography has a very good chance of being adopted by the semiconductor industry, thanks to its unprecedented resolution.
* The results obtained on assemblies of nanoparticles show that these nanomaterials are very few steps away from the ability to fabricate "single-electron" transistors, three-dimensional arrays for photonic bandgap materials, and nano-domain confinement of molecular electro-optic materials for photonic devices.
As a matter of fact, the current work on self-assembly has been highlighted and singled-out by the vice-president for research at Intel Corporation as one of the few viable alternatives for large-scale nanofabrication for CMOS and beyond CMOS technologies. The impact on economy and society of such advanced nanofabrication techniques is very large.
These results can be very relevant for industrial companies working in the semiconductor, advanced materials, sensor and optoelectronics areas. As a result of DAPOMAN, there is now continuing collaboration between the host and guest groups (UPM-ISOM and U. Wisconsin-Madison) with a focus on the investigation of the impact of self-assembly and entropy driven transitions in biological systems, and on genetic diseases caused by protein mis-folding. Research in this area could also have an impact on society in general through its medical applications.
The figure attached shows snapshots of the first observation of self-assembly of hard-sphere linear chains as obtained from MD simulations.
The key driving idea is to use self-assembling materials to create regular structures at the nanoscale which then serve as templates or patterns for the fabrication of nanodevices in the area of the semiconductors, nonlinear optical materials, nanostructured and graded materials.
The collaboration between the visiting scientist and the host institution focused mainly on the development of a first-principles approach to the modeling of self-assembly in complex materials, mainly homo- and co-polymers,. This approach is based on multiscale, hierarchically organized modeling methods that range from atomistic Molecular Dynamics (MD), to coarse-grained Monte Carlo (MC).
This suite of models were directly tested and applied to a wide variety of systems of quite different nature in order to assess their flexibility and reliability. In particular, two families of materials were addressed:
* self-assembly of thin copolymer films on nanoscale patterned surfaces (basically two-dimensional systems)
* self-assembly of hard-sphere systems, including both monomeric (single spheres), and polymeric ones (linear chains of spheres).
The key result achieved in the reporting period is that the suite of hierarchical methods, each operating at different spatial and temporal scales can successfully predict the expected or experimentally observed morphologies at the nanoscale level.
Furthermore, it has also been able to predict novel, entirely unexpected self-assembling morphologies. Prominent among these unexpected results is the finding that materials with a molecular structure of linear chains of hard spheres can spontaneously self-assemble in almost perfect random stackings of hexagonal layers. This discovery disproves a long-standing conjecture that connectivity suppresses entropic crystallization and opens the door to new methods of self-assembly which have not been explored up to now.
The achieved final results have major potential for application on two fronts:
* The development of resists using the DAPOMAN methodology based on self-assembling materials for nanolithography has a very good chance of being adopted by the semiconductor industry, thanks to its unprecedented resolution.
* The results obtained on assemblies of nanoparticles show that these nanomaterials are very few steps away from the ability to fabricate "single-electron" transistors, three-dimensional arrays for photonic bandgap materials, and nano-domain confinement of molecular electro-optic materials for photonic devices.
As a matter of fact, the current work on self-assembly has been highlighted and singled-out by the vice-president for research at Intel Corporation as one of the few viable alternatives for large-scale nanofabrication for CMOS and beyond CMOS technologies. The impact on economy and society of such advanced nanofabrication techniques is very large.
These results can be very relevant for industrial companies working in the semiconductor, advanced materials, sensor and optoelectronics areas. As a result of DAPOMAN, there is now continuing collaboration between the host and guest groups (UPM-ISOM and U. Wisconsin-Madison) with a focus on the investigation of the impact of self-assembly and entropy driven transitions in biological systems, and on genetic diseases caused by protein mis-folding. Research in this area could also have an impact on society in general through its medical applications.
The figure attached shows snapshots of the first observation of self-assembly of hard-sphere linear chains as obtained from MD simulations.