INTERFEROMETRIC DETECTION OF ADHESION-INDUCED NANO-DEFLECTIONS

A novel micro-tribology tester comprising a highly sensitive force-det ecting cantilever and a single-beam interferometer is introduced. To a void any disturbance of the highly sensitive mechanical set-up the fro nt side of the cantilever was polished to create the necessary reflect or. The interferometer utilizes an aperture through which the interfer ogram is evaluated. In contrast to an atomic force microscope, where o nly a sharp tip interacts with the surface, two planes can be brought into contact. To measure adhesion one of the two samples is attached t o a piezo-stack, performing an oscillatory motion towards and away fro m the second sample. Since the second sample is attached to the cantil ever, any displacement can be detected by the interferometer. With a c antilever spring constant of 5 N m(-1) and an interferometer length re solution of 1 nm, forces down to 5 nN can be resolved.