30 years and 9,000 citations later the inventors of the Atomic Force Microscope (AFM) were recognized today with the with the Kavli Prize in Nanoscience.
The Prize is shared between Gerd Binnig, Christoph Gerber and Calvin Quate. Binnig and Gerber were previously with IBM Research – Zurich and they collaborated with Quate from Stanford University, while on sabbatical (Binnig at Stanford, Gerber at IBM Research in San Jose, now Almaden).
The three scientists receive the prize “for the invention and realization of atomic force microscopy, a breakthrough in measurement technology and nanosculpting that continues to have a transformative impact on nanoscience and technology.”
The AFM was first published on 3 March 1986 in the peer-review journal Physical Review Letters with the simple title “Atomic Force Microscope.” The invention combined the principles of scanning tunnelling microscopy (STM) and the stylus profilometer to detect atomic resolution. Binnig co-invented the STM a few years earlier with the late Heinrich Rohrer and they both received the Nobel Prize for Physics in 1986.
Binnig, who is solely listed on the first patent, was quoted in IEEE Spectrum Magazine in 2004 saying that the idea for the AFM came to him subconsciously while he was lying on the couch. While at Stanford he involved Calvin Quate and his IBM colleague Christoph Gerber, with whom he had already collaborated for the development of the STM, and together they realized the AFM.
Gerber, who was recently interviewed in Physics World magazine about the 30th anniversary of the AFM, commented on the evolution of the invention:
“Gerd suggested that it might be possible to measure the interactive forces, rather than the current, between tip and sample, and that perhaps we could do this with a cantilever. We did a rough calculation and realized that in order to get atomic resolution we needed to be able to detect forces at the level of 10–10 N or even 10–11 N!”
The secret to measuring the tiny atomic forces were delivered by two precious elements: gold and diamond. Gerber comments in Physics World:
“The heart of the device was a very thin gold foil just a few microns thick used as a cantilever. We took a fragment from a crushed diamond obtained from the stylus of a record player and glued it onto the cantilever to serve as a tip.”
“We did not get atomic resolution straight away but we were close enough to submit a journal paper. Within a year we had a more advanced instrument based on a batch-fabricated silicon cantilever that showed atomic resolution for the first time on a graphite surface.”
After their seminal work, the three pushed AFM technology in several new directions, in particular with respect to cantilever design and applications.
Binnig adapted the cantilever design to create a massively parallel probe for nanostructing, aimed at the development of non-volatile memory. This work has spun off a number of innovations, including nanopatterning techniques.
At IBM, Gerber developed an “artificial nose“ using a cantilever array, which has proven successful in the fields of chemical and biochemical reactions as well as in medical applications. He continues this research today in his research group at Basel, Switzerland.
Quate has focused on micromechanical cantilevers for sensing applications for drug discovery, food diagnostics, material characterizations and explosives detection.
Within the past 30 years, AFM instruments have seen tremendous development with respect to sensitivity, resolution and application spreading into diverse fields.
For example, in 2008 Markus Ternes and co-workers at IBM Research – Almaden used this detection scheme to slide single atoms across a surface using an AFM and also to directly measure the forces involved.
A year later a team of IBM scientists in Zurich, led by Gerhard Meyer and Leo Gross, modified the tip of their AFM with a single carbon monoxide molecule. This diatomic molecule, which is less than one nanometer long, produced images with such high resolution that internal chemical structure of a single molecule could be resolved (chemical bonds).
Gross comments, “One main differentiator of our technique, with respect to other established techniques, is that we measure single molecules. Another advantage is that we can use the tip to initiate chemical reactions of individual molecules and we can follow the reactions and study their products at the atomic scale.”
Meyer and Gross with their colleague Bruno Schuler recently published an article on the 30th anniversary of the AFM in Physics World:
“Importantly, a high-resolution AFM offers opportunities to understand and control physical, chemical and biological processes at the level of individual molecules. Ongoing improvements in force sensitivity plus temporal and spatial resolution will push the frontiers in nanoscience further. Perhaps in another 30 years the AFM might be further improved towards an atomic assembler as addressed by Richard Feynman in his famous 1959 talk “There’s plenty of room at the bottom”: a tool that might build arbitrary, 3D atomically precise devices, metamaterials and molecules.”
“Either way, there is no doubt that the AFM will continue to promote discoveries from fundamental physics all the way to chemistry and the life sciences, unravelling nature’s most enigmatic mechanisms at the nanometre scale and beyond.”
This is the second time IBM scientists have been awarded the Kavli Prize. Don Eigler won the 2010 Kavli Prize in Nanoscience for the development of atom manipulation and for the elucidation of quantum phenomena with precisely controlled atomic and molecular arrangements on surfaces.
The Kavli Prizes recognize scientists for pioneering advances in our understanding of existence at its biggest, smallest, and most complex scales. Presented every two years in the fields of astrophysics, nanoscience and neuroscience, each of the three international prizes consists of $1 million (U.S.). Laureates are chosen by committees whose members are recommended by six of the world’s most renowned science societies and academies.