Combining atomic force microscopy and shear-force acoustic near-field microscopy to characterize confined mesoscopic fluids

An atomic force microscopy (AFM) cantilever is integrated into to a quartz tuning fork (QTF) to probe the viscoelastic properties of mesoscopic fluid layers confined between two solid surfaces under shear. Two procedures to fabricate the AFM/QTF probe are described herein. In the first, a nano-manipulator is used to transport a commercially available afm cantilever from its chip holder to the edge of a QTF tine. In the second, an afm cantilever is fabricated at the edge of the QTF tine itself. In both cases we exploit the capabilities of a dual-beam system (focused ion beam/scanning electron microscope), equipped with Omni-Probe nano-manipulator and a Gas Injection System (GIS). The new device improves the ability of shear-force acoustic near-field microscopy (SANM) to monitor the constraining normal and damping shear forces exerted by the solid boundaries, concurrently with the acoustic emission from the trapped fluid. (paper)