Developmet of Wide Range Tribo-Tester Using Scanning Probe Technique

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To evaluate tribological characteristics of surface using the scanning probe method, wide range of applying forces to the probe, clear separation in measured vertical and horizontal forces and high durability of tip against sliding motion are essential. For this purpose, a cantilever with a diamond tip glued onto it was selected.First, a novel cantilever structure having a function for measuring vertical and horizontal forces separately was proposed. Special feature of this structure was twin levers extended from a base lever and bridged with a top lateral bar having a diamond tip. This structure was confirmed to permit torsional and vertical displacements to be measured separately using differential signal from the twin levers and direct signal form the base lever.Second, the Michelson laser interferometry was applied for measuring three-dimensional displacement of the cantilever. Fringe pattern formed over the cantilever surface was captured using a ultra-high speed VTR,then the image data were analyzed to provide vertical and horizontal forces, simultaneously.Finally, a silicon cantilever doped with N-type atoms was fabricated for directly measuring the force from the cantilever strain. Linearity and sensitivity were experimentally clarified, and mechanical characteristics, such as, stiffness and effective mass were identified using resonance of the cantilever.