Near-field scanning optical microscopy: Development of instrumentation for biological imaging

Near-field scanning optical microscopy (NSOM) is a scanned probe microscopy capable of high resolution (∼50nm) optical imaging of a surface under ambient laboratory conditions. A non-optical method for topographic control of the near-field probe was developed and characterized. The mechanism of shear-force feedback was investigated in air and water. Adhesion forces were found to exceed the maximum load forces for living cells. The applicability of NSOM to the imaging of living biological tissues was extended by adopting an AFM type geometry for topographic control. Cantilevered fiber optic near-field probes were manufactured, characterized and integrated into a scanning AFM/NSOM head. Material limitations of cantilevered fiber optic probes lead to the design of a near-field microelectromechanical microscope capable of imaging in both air and water.