“Top Down” and “Bottom Up” approaches in chemistry

Anant Babu Marahatta
Ph.D. student in Chemistry
Tohoku University
Japan

Who are chemists? Most of you definitely agree with me if I said “Chemists are scientists trained in the field of Chemistry and describe the properties of the matter on the level of molecules and their component atoms.” But if I said “Chemists are ‘tailor’ who make the world fashionable by implementing “top down” and “bottom up” approaches” in chemistry, most of you get confused.

Even though “Top down” and “Bottom up” approaches of chemistry were first applied to the field of nanotechnology in 1989, these terms are not so much familiar among the chemists like us. Thus this article is intended to describe the principles and the perspectives of these approaches which have grown exponentially in the last few decades.

To describe the “top down” approach, let us consider a macroscopic system and break down into the several subsystems and then start analyzing these subsystems and refine them in greater detail until the entire composition is reduced to their base elements. It can be clarified by saying that “top down” is the destructive approach to go insight into the fundamental level [going top to down] and adapt their features to make them functional at a smaller scale. Though it is a traditional way, Chemists sometimes consider the hypothesis which starts at the top with the most general concepts and works down through less general concepts to the most specific details.

On the other hand, the “bottom up” technique is based on the principle of starting from the fundamental [bottom] parts and assembled [going up] them to obtain the desired more complex system [going bottom to up]. Thus, it is the constructive approach to stitch the fundamental parts together and develop the new inventions.

In chemistry, the “bottom up” approach makes the use of atomic/molecular components and assembled them to develop the potential nano-devices. This approach is already implemented even for interconnecting the multiwalled carbon nanotubes into the multilevel interconnects (silicon integrated-circuit) with higher current conducting capacity.

To conclude, both “top down” and “bottom up” approaches in chemistry have their contribution to the development of nanotechnology but as far as the future is concerned the “bottom up” is a promising technique for the most effective and smart molecular architectures.

I would like to see you all as a “stylist of the nano-world” in the near future.