Atomic force microscope probe based controlled pushing for nanotribological characterization

Using an atomic force microscope (AFM) probe as a nanomanipulator, micrometer- and nanometer-sized objects, especially particles, are pushed on substrates for characterizing the object-substrate friction parameters and behavior in various environments, e.g., air, liquid, and vacuum. Two possible nanotribological characterization methods are proposed in this paper: 1) sliding the micro/nano-object on the substrate while it is attached to an AFM probe and 2) nanorobotic pushing of the micro/nano-object with the sharp tip of an AFM probe. The modeling of these methods are realized and experiments are conducted for the latter method using a piezoresistive AFM probe as a one-dimensional force sensor and nanomanipulator. In the experiments, 500-nm radius gold-coated latex particles are pushed on a silicon substrate. Preliminary results show that different frictional behavior such as sliding, rolling, and rotation could be observed, and shear stresses and frictional behavior could be estimated using these techniques at the nanoscale.