What is Rational Design?

In an increasingly competitive market, companies no longer have enough time, people or resources to dally over the discovery of new materials, drugs and so on, or to spend months testing thousands of candidate molecules in the search for the best one to match their requirements. Research has had to become much more focused and find more efficient ways of driving discovery. These are generally named under the umbrella term of 'Rational Design'.

The old ways

Obviously, the 'old' ways of carrying out research were not too bad - amazing things were learnt, great discoveries made. It is simply that today's market drives companies and researchers to do more with less in a shorter time. Rational design methods make sense in this atmosphere, for their efficiency in getting through the discovery process to a marketable product, if nothing else. But were the old ways so bad? And what are the differences?

Take a look at the Discovery Process Target to see how the Discovery process has changed recently.

The Rational Process

You start with the problem you want to solve — a more efficient reaction, a rubber that gives car tires better grip in the wet or a material that can pop back into shape after an impact for example
You develop an understanding of the problem at a fundamental level. Why is that reaction not running faster? What gives rubber tires grip, and what decreases that grip on wet roads? What happens when a material deforms during an impact? Is it reversible?
The investigation and understanding phase might involve the use of modeling and simulation software to perform virtual experiments or look at materials structures on the molecular level
With your new understanding of the issues, you can begin to perform targeted research and development. This is where rationality comes in — first spend a little time and effort gaining understanding and then look for a tailor-made solution to that problem. This should leave you with a compact, targeted list of potential solutions that can then go into a 'real life' experimental phase
Once you have validated your research and chosen a final candidate, you can proceed to manufacture. This might in itself involve some research into new methods and processes.

The Advantages of Rational Design

You gain understanding of a particular problem or system. This understanding, at such a fundamental level, may enable future problems to be solved faster and more efficiently
You reduce the amount of costly, labor-intensive laboratory experimentation or fieldwork that needs to be done to solve a specific issue. You already know the direction you need to head in, and so can dismiss a proportion of potential solutions straight away. Virtual experiments (in silico experimentation), computer modeling and simulation all help to travel towards an answer before having to spend time, money, resources and people on solving the problem
More virtual and less laboratory experimentation often means fewer chemicals and reagents are used, which saves money and can be better for the environment ('green chemistry')
The end results are generally 'better out of the box,' being designed from scratch to be more effective at solving the original problem.

The Rational Drug Design Experience

One major area of research and development with many similarities to nanotechnology in which rational design methods have been tried extensively in recent years is drug discovery. Rational drug design (RDD) methods aim to generate and optimize pharmaceutical lead compounds based on a detailed understanding of their potential mechanism of action, usually by using computer simulation to model the likely interaction of potential drugs with a target site in a protein. That these methods are successful and valued by the organizations that use them is borne out by the fact that such computer modeling is now integral to every serious drug discovery program.

However, some lessons from the development of RDD are worth considering as we consider nanotechnology. The most important of these is around the issue of integration — RDD has most impact where it is integrated well into a wider rational discovery process, and not seen as an isolated computer-based technology. It has least impact where it is seen as the sole preserve of computational chemists and disconnected from experimental and other work. Similarly, within computational drug discovery, there has been a tendency for new methods and areas of application to be developed independently, often within proprietary systems that do not 'talk' to one another. An enormous amount of effort is now being expended in unpicking these systems and enabling them to work together, so that chemists, biologists, and computational specialists can share their benefits. Nanotechnology has the opportunity to get this right first time.

When these principals are applied to the study and development of materials or anything else at the nanoscale, it is called Rational Nanotechnology.