Materials Modelling

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Integration of atomistic modelling into product design

The atomistic modelling field has grown substantially over the last 10 years, and reached a level of maturity which makes a more routine type of application and integration into engineering and product design a viable option. At the same time, product design has reached scales that are close to atomistic, and also involves exploring an ever larger space of potential new materials across the element table.

Here is some evidence:

The growth of the simulation field was demonstrated very nicely by a recent study based on publications in the ab initio field by the Psi-k network. It shows a strong increase in the number of (unique) people publishing papers based on ab initio methods from about 3000 in 1991 to about 20,000 in 2009, with particularly strong growth in East Asia. If one adds people who use other techniques such as molecular dynamics, and researchers in industry that don’t publish their work, it should be safe to assume that there are more than 30,000 users of some sort of atomistic technique.

This level of growth is also linked to the robustness of the codes and the speed of standard hardware. These together with the experience that has been gained regarding the types properties that can be calculated at a certain level of accuracy have increased the impact of atomistic simulation in many industrial applications.

Also, atomistic techniques support the combinatorial exploration of the large materials phase space. For example, the iCatDesign project in the UK explored alloys for fuel cell catalysts, considering both the combination of different elements as well as structural aspects. The online library of binary alloys from the Energy Materials Lab at Duke  is an example of structure calculations that aid in the discovery and development of new materials. Considering ternary alloys are becoming more important in meeting complex requirements in high performance applications such as aerospace and energy generation, and the fact that only about 5% of ternaries are known, such modelling approaches will become even more relevant in new materials design. Also, in other areas such as polymer and composite design, early adopters are demonstrating the usefulness of integration, for example Boeing reported that they “integrated molecular simulations into the materials design process” and their work “demonstrates that the future of aerospace materials development includes simulation tools”.

Despite the growing importance and opportunity of a stronger integration of atomistic methods into engineering design, this is still an area in its infancy, but promoted strongly as part of a wider agenda such as Integrated Computational Materials Engineering (ICME). One of the key questions I am interested in is how the integration is actually achieved. For example, will integration of the modelling methods themselves be required, as in multiscale methods?

While multiscale methods are important for some applications, their significance for integration may be overrated, as was also concluded by the report on ICME report. Rather, the focus needs to be on a more detailed analysis of design workflows, and their intersection with the information that can be determined well at the atomistic scale.

A design workflow typically includes a number of selection stages, at which decisions are made regarding materials and processes. These will be informed by available data from a number of sources and should include atomistic modelling where appropriate.  This type of approach has been reported for example by Massimo Noro from Unilever, who talks about selection criteria as “emerging physico-chemical criteria we can evaluate in practice that help us select ingredients”. Also Oreste Todini from Procter & Gamble promotes the use of modelling in the decision process to come up with lead options for new formulations.

So there is evidence of an integrated design approach from early adopters such as Boeing, Unilever and Procter & Gamble.  In order to establish integration more widely, engineering and science communities need to collaborate more closely. The atomistic simulations community needs to improve the way in which best practices are established, shared and linked with engineering workflows. Informatics frameworks are being established, for example with the integration of Materials Studio in Accelrys’ Pipeline Pilot platform, and projects such as iCatDesign and MosGrid. However, integration into engineering rather than chemistry platforms may be what is required.