2010 Nanoscience Citation
|The Norwegian Academy of Science and Letters awards the
2010 Kavli Prize in Nanoscience to:
Donald M. Eigler
IBM Almaden Research Center,
Nadrian C. Seeman
New York University, US
|“for their development of unprecedented methods to control matter on the nanoscale”|
A CENTRAL THEME OF NANOSCIENCE is the ability to control the arrangements and patterns of matter on a very small scale. The aim is to put specific atomic, molecular, and nanoscale species where we want them, and when we want them there. With such control it is possible to understand complex systems and to build new structures from the ground up with desired functions.
A seminal development in the field of nanoscience occurred when Don Eigler demonstrated a specific case where it was possible to pick up and place individual atoms at will. In the lecture that presaged the field of nanotechnology by decades, Richard Feynman famously said: “But I am not afraid to consider the final question as to whether, ultimately – in the great future – we can arrange the atoms the way we want; the very atoms, all the way down! What would happen if we could arrange the atoms one by one the way we want them (within reason, of course; you can’t put them so that they are chemically unstable, for example) … The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not an attempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are too big.”
Donald M. Eigler
Donald Eigler is recognized with the Kavli Prize in Nanoscience for the development of Atom Manipulation with the STM and for the elucidation and demonstration of quantum phenomena with precisely controlled atomic and molecular arrangements on surfaces.
Decades later, Eigler realized this vision. The invention of the scanning tunneling microscope by Binnig and Rohrer provided a tool that could be used to observe individual atoms. Shortly after, using a low-temperature scanning tunneling microscope, Eigler began to investigate the properties of individual atoms deposited on a metal surface. Soon he found that when he dropped the tip close to the surface, an atom would jump from the surface to the tip. After “picking up” one atom, he could release it back to the surface in another location, by applying a voltage pulse. In 1989, he showed that he could perform these operations repeatedly, in a controlled fashion, so as to write words with atoms. This represents a breakthrough in the history of the control of matter.
Eigler subsequently used atom manipulation to create a whole field of quantum engineering. First, he showed the formation of “quantum corrals,” based on creating a circle of 48 Fe atoms with a diameter of 14,3 nm on a Cu surface. The natural electron waves on the Cu surface were confined by the Fe atoms, leading to a well-defined quantum wave pattern. This provided a quantitative tool for learning how these electrons were interacting with their environment and provided compelling images of the wave properties of electrons. Eigler also demonstrated the formation of “quantum mirages,” in which the quantum behavior of electrons confined to an elliptical shape were investigated.
Eigler demonstrated the ability to manipulate molecules as well as atoms. He fabricated and operated novel logic circuits made from carbon monoxide molecules on a Cu surface. He showed that these molecules could be made to shift their orientation on the surface. When the molecules were adjacent, shifting one molecule could result in a cascade of shifting events. Using this, Eigler demonstrated all of the logic elements and circuits required to perform the one time calculation of an arbitrary logic function. These were the first computational structures in which all of the components necessary for computation were at the nanometer length scale; it served to underscore the importance of investigating alternative modes of computation in nanometer-scale structures. More recently, Eigler has investigated single atom spin excitation phenomena.
Nadrian C. Seeman
Nadrian Seeman is recognized with the Kavli Prize in Nanoscience, for inventing DNA nanotechnology, for pioneering the use of DNA as a non-biological programmable material for a countless number of devices that self-assemble, walk, compute and catalyze.
Nadrian C. Seeman conceived the idea of using DNA as a building material for nanoscale engineering, rather than as the genetic material. His creations range from DNA cubes, to tubes, rings, tiles, and crystals, and promise breakthroughs in future applications in fields ranging from electronics to biology.
DNA is built up from sequences of four bases (A,G,T,C) along each single strand. Two complementary strands of DNA base pair to form the famous double helix. Seeman designed specific short strands of DNA containing precise sequences of base pairs that will spontaneously pair up in such a way as to form complex designed structures. A hallmark of this method of patterning matter is that, once the sequences are designed and mixed together, they “self-assemble” into the desired three dimensional pattern.
In 1980, Seeman started the field of DNA nanotechnology with the idea of using the structural information in DNA to organize matter on the nanometer scale in three dimensions. To achieve this goal, he worked out the theory of assigning sequences to DNA strands so that they would self-assemble into target branched species. Seeman spent years developing an understanding of the rules for DNA strand design, so that no structure other than the desired one would form. Using single-stranded cohesion, he guided these branched DNA molecules into stick polyhedra, such as a cube and a truncated octahedron. Topological targets, such as deliberate DNA knots and Borromean rings were likewise readily accessible to the methods he developed. He went on to develop motifs robust enough to be used as the components of both crystalline lattices and of nanomechanical devices. He patterned two-dimensional periodic arrays of DNA. Seeman used robust two dimensional arrays of DNA to dictate the arrangement of metallic nanoparticles into a checker board pattern. He designed the first DNA-based nanomechanical device, as well as robust individually-addressable 2- and 3-state nanomechanical devices. He developed ways in which DNA could be used to operate a robot arm, to capture target species, and to translate DNA sequences into polymer assembly instructions. Later, he developed DNA-based clocked and autonomous walkers. Most recently, he produced a programmable DNA-based assembly line.