Lift mode

The SPM technique allows measurements of the local sample surface potential. The NanoScope recorded two passes. In the first pass, the sample surface topography was obtained by the standard tapping mode. The surface potential was measured during the second pass carried out in the lift mode (lift height was 100 nm). Here the cantilever s vibration is turned off and an oscillating voltage U c cos cot is applied directly to the cantilever tip. This creates an oscillating electrostatic force F at the frequency co on the cantilever ... 

Using an SFM-type microscope, measurements of electrical properties have to be performed either in contact mode, i.e. with the conductive SFM tip being in mechanical contact with the surface, or in non-contact mode, a dynamic mode with vibrating cantilever, or in the so-called lift mode, where a line is repeatedly scanned with a chosen and controllable tip-surface distance. Contrasts of capacitance, dielectric constants or potentials can be achieved both in the contact and in the non-contact mode, and the quality of the result is not influenced by the sensitivity of the chosen instrument alone. All the sample properties (most of all sample thickness and size) affect the sensitivity of both methods, so that the prediction of the most successful technique is not always possible. 

Walczyk W, Main N, Schbnherr H. Hydrodynamic effects of the tip movement on surface nanobubbles a combined tapping mode, lift mode and force volume mode AFM study. Soft Matter 2014 10 5945. 

FIGURE 21.6 Lift-mode AFM-SG/TC mode SECM images of an array of 1 gm diameter disk microelectrodes. (a) Topography image, (b) Tip current image. The probe was biased so as to detect the reduced form of the mediator (ruthenium hexamine Ru(NH3)5 ) produced at the disk microelectrodes from its oxidized form introduced in solution. The AFM-SECM configuration allowed individual microdisk electrodes to be resolved and their electrochemical activity to be probed. (Erom Dobson, P.S. et al.. Anal. Chem., 11,424, 2005. With permission.)... 

Dielectric relaxation of supported polymer films was measured for dry as well as wet samples by using the LDS method. A Veeco Multimode AFM (Nanoscope Ilia with ADC5 extension) was adapted to a frequency-modulated electrostatic force microscope (FM-EFM) and operated in lift mode (details are reported in Refs. [41, 47]) FM-EFM with improved bandwidth was here implemented through a RHK Technology PLLProll phase-locked-loop (PLL) frequency detector, having a nominal response bandwidth of 4 kHz that could be extended to about 10 kHz by... 

Second pass (lift mode) electric field... 

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