Full text loading...
(a) Experimental setup. A conical AFM probe is extended with an amorphous carbon whisker. The whisker is partially submerged in the thin liquid layer and scanned at different velocities. The torsion on the AFM probe is continuously monitored. (b) An electron micrograph of the carbon whisker with an average diameter of (courtesy of MikroMasch).
A typical velocity profile, derived from the horizontal position detector signal. Inset: the raw signal from the position detector. The apparent noise is originated from the detector rather than the scanner.
Drag force–velocity relation (), recorded at constant immersion depth. The solid line is calculated from the Stokes law by using the drag coefficient given for an ellipse with the projected diameter and length of the immersed section of the probe. The fitting parameter was the viscosity (and a constant offset).
Drag force per unit length as a function of immersion depth at constant velocity.
Drag force per unit length as a function of velocity, recorded at different submersion depths; just above the mica surface, above the mica surface, at the air–liquid interface.
Article metrics loading...