Researchers at IBM’s Almaden Research Centre have demonstrated the first magnetic resonance imaging (MRI) techniques which can be used to visualise nanoscale objects. The technology represents a major milestone in the quest to build a microscope that could ‘see’ individual atoms in three dimensions.
Using Magnetic Resonance Force Microscopy (MRFM), the researchers demonstrated 2D imaging of objects as small as 90 nanometres. Such imaging could ultimately provide a better understanding of how proteins function, which in turn may lead to more efficient drug discovery and development.
‘Our ultimate goal is to perform 3D imaging of complex structures such as molecules with atomic resolution,’ said Dan Rugar, manager, Nanoscale Studies, IBM Research. ‘This would allow scientists to study the atomic structures of molecules such as proteins which would represent a huge breakthrough in structural molecular biology.’
MRFM offers imaging sensitivity that is 60,000 times better than current magnetic resonance imaging (MRI) technology. MRFM uses what is known as force detection to overcome the sensitivity limitations of conventional MRI to view structures that would otherwise be too small to be detected.
To achieve this, the research team developed specialised magnetic tips for their microscope, optimising their ability to manipulate and detect the very weak magnetism of atomic nuclei. Conventional medical MRI typically operates on a scale at least 1,000 times coarser; even the most specialised MRI microscopy is limited to about three micrometres, or 3,000 nanometres.
This achievement could eventually have major impact on the study of materials ranging from proteins and pharmaceuticals to integrated circuits for which a detailed understanding of the atomic structure is essential. Knowing the exact location of specific atoms within tiny nanoelectronic structures, for example, would enhance designers’ insight into manufacture and performance. The ability to directly image the detailed atomic structure of proteins would aid the development of new drugs.