Dynamic AFM for soft surfaces
of DNA where the width of the DNA is convoluted with that
of the AFM tip, and the measured height can be affected
by the imaging force and other parameters
In Atomic Force Microscopy (AFM), precise control of the probe-sample interaction force is essential for imaging very soft samples such as biological surfaces. The ability to image at near molecular resolution of such surfaces in ambient / physiological conditions requires this force to be sufficiently large to provide significant contrast in the AFM images, however, not so large that it will deform the sample. To achieve this, we are addressing the metrological and calibration issues related to drift, drift rate, tip shape, the nanomechanics of cantilevers and control of the tip location and forces. We are working on developing a detailed understanding of the imaging modes, such as frequency modulation mode and multi-frequency modes, and comparing these to more traditional AFM imaging modes. These new modes will be used to study intricate detail of biological surfaces, agglomeration of bio-molecules, emulsions and interactions between nanoparticles and bio-surfaces.
Selected Publications
[1] Simplified drift characterization in scanning probe microscopes using a simple two-point method, C A Clifford and M P Seah, Meas. Sci. Technol. 20 095103 (2009).
[2] Sample preparation protocols for realization of reproducible characterization of single-wall carbon nanotubes, J E Decker, A R Hight Walker, K Bosnick, C A Clifford et al, Metrologia 46 682–692 (2009).
If you require PDF copies of the publications, please contact us below.
Contact: Charles Clifford or Deb Roy