Wednesday, October 11, 2006

My favourite Nobel

The 1986 Physics Prize recognized some of the key achievements that played -- and continue to play -- a pivotal role in materials science. One half of the Prize went to Ernst Ruska for his "fundamental work in electron optics, and for the design of the first electron microscope", and the other half was shared by Gerd Binnig and Heinrich Rohrer for their "design of the scanning tunnelling microscope".

The Nobel Foundation's website has a nice page on TEM; curiously, its photo gallery of TEM images are only from biological specimens! This page and this Wikipedia entry are also quite informative.

Nobel Foundation also has a page on STM; the Wikipedia entry is here. An image gallery is hosted by IBM's Almaden Research Center.

The electron microscope -- specifically, the transmission electron microscope, or the TEM -- opened up the innards of materials, and allowed scientists to get a clear view of phenomena and processes at extremely small scales -- down to one nanometer. We can tweak modern microscopes to reveal secrets even at the atomic scale (down to 0.2 nanometer) (however, since electrons have to pass through -- hence the qualifier 'transmission' -- a layer of material, these 'atomic' level secrets are somewhat blurred).

On the other hand, the Scanning Tunnelling Microscope (STM), is a surface probe that tells us about the structure -- arrangement of atoms and molecules -- at the surface. As Gerber and Lang note in this article (in the first issue of Nature Nanotechnoloty), the invention of STM is one of the "crucial events in the history of nanoscience and nanotechnology".

Research at the nanoscale is expensive primarily because of gadgets such as the electron microscope, STM and its cousins such as the Atomic Force Microscope. As Prof. C.N.R. Rao said in his plenary lecture at Nano-2006, 'doing' chemistry at the nanoscale -- synthesizing nano-sized compounds by exploiting interesting chemical principles -- is actually quite easy and inexpensive. With strong chemical insight and intuition, all one needs is basic infrastructure that can be found in a high school or a junior college! It is only the associated machinery required for probing the structure, chemistry, properties, etc, which makes nanoscience an expensive enterprise.

To get back to the topic of this post, I have to confess that the 1986 Physics Prize is my favourite simply because the achievements it celebrates are things that are useful for us materials scientists and engineers; more importantly, these are achievements I understand and relate to, and I can't say this about any of the other science Nobels from any era!

However, here is one more factoid which I'm sure you would find interesting: this Prize recognized research from two very different times: the electron microscopy work dates back to the 1930s, while the STM work is from the early 1980s. Thus, in terms of the time gap -- ΔT -- between the actual work and the Prize, then the 1986 Nobel in physics is unique in that it has both the longest and the shortest ΔT!

Let me end this post with a quote from Gerber and Lang's short history of STM and its cousins in Nature Nanotechnology (which actually triggered this post):

The initial results [on the design of STM] were written up in a manuscript entitled "Tunnelling through a controllable vacuum gap", which was submitted to a leading physics journal in June 1981. However, the paper was declined by the editors based on the following referee reports: one referee said that the exponential dependence of the tunnelling current on distance was well accepted, so the experiment would not give any new insight; the other report described the work as "extraordinary" and a "technical jewel", but this referee said that whether such technological work should be published in this particular physics journal was an editorial decision. Eventually the results were published in another leading journal, Applied Physics Letters, in January 1982.


  1. Arun K. Subramaniyan said...

    I like your reason for choosing this Nobel as a favorite. I agree that this is one of the very rare Nobel's that engineers can actually relate to.

    Another slightly off topic point is the original paper by Gerber being rejected the first time. There are many such examples of great breakthroughs being rejected the first time (Eshelby's inclusion paper for example). I sometimes use this to cheer myself when I get a bad review.