MRI has had a revolutionary impact on non-invasive imaging both for medical purposes and for microscopic studies of biological systems. However, the relative insensitivity of inductive detection via resonance force coils prevents conventional MRI techniques from achieving resolution better than 10 um. Recent theoretical and experimental work has shown that any magnetic resonance (MR) experiment, originally performed using conventional inductive techniques, can also be performed using microscale mechanical resonators and the technology of force microscopy. While current inductive detection limits are on the order of 10(15) nuclear spins, mechanical detection is revolutionary because the theoretical sensitivity is a single nucleon. To date, both electron and nuclear MR signals have been successfully detected by mechanical means, validating the theory of mechanical detection of MR. Several laboratories are now racing towards developing this technology for materials science applications in semiconductor chips. The investigator proposes to develop and apply highly sensitive MR force microscope (MRFM) technology for performing 3-D imaging of biological systems. This exciting new technology combines recent developments in force microscopy with the ability to mechanically detect MR signals using micromechanical oscillators and fiber optic laser interferometry. The proposed MRFM will allow one to perform direct, non-destructive, chemical specific, three-dimensional imaging of biological systems. No other technology (currently available or proposed) has this capability. The successful development of this technology will result in significant benefits in the areas of biomedical research and diagnosis including the areas of pathology and histology, neuroscience, and structural biology, and pharmaceutical development. It is believed that two years of work will set the stage for unprecedented investigations of structure and chemistry of biological systems. This work will exploit the 3-D imaging capability of MRFM technology. The unique power of the MR techniques for imaging has been demonstrated repeatedly. MRFM offers the possibility of carrying out these same experiments with molecular scale resolution. The potential MRFM offers for gaining new insights into the physical nature of systems of great biomedical importance is truly exciting.
