Practical loss tangent imaging with amplitude-modulated atomic force microscopy

2016 ◽  
Vol 119 (13) ◽  
pp. 134901 ◽  
Author(s):  
Roger Proksch ◽  
Marta Kocun ◽  
Donna Hurley ◽  
Mario Viani ◽  
Aleks Labuda ◽  
...  
2014 ◽  
Vol 47 (22) ◽  
pp. 7971-7977 ◽  
Author(s):  
Hung K. Nguyen ◽  
Makiko Ito ◽  
So Fujinami ◽  
Ken Nakajima

Open Biology ◽  
2014 ◽  
Vol 4 (5) ◽  
pp. 140046 ◽  
Author(s):  
Jan Rother ◽  
Helen Nöding ◽  
Ingo Mey ◽  
Andreas Janshoff

Mechanical phenotyping of cells by atomic force microscopy (AFM) was proposed as a novel tool in cancer cell research as cancer cells undergo massive structural changes, comprising remodelling of the cytoskeleton and changes of their adhesive properties. In this work, we focused on the mechanical properties of human breast cell lines with different metastatic potential by AFM-based microrheology experiments. Using this technique, we are not only able to quantify the mechanical properties of living cells in the context of malignancy, but we also obtain a descriptor, namely the loss tangent, which provides model-independent information about the metastatic potential of the cell line. Including also other cell lines from different organs shows that the loss tangent ( G″ / G′ ) increases generally with the metastatic potential from MCF-10A representing benign cells to highly malignant MDA-MB-231 cells.


2021 ◽  
Vol 11 (15) ◽  
pp. 6813
Author(s):  
Babak Eslami ◽  
Dylan Caputo

Atomic Force Microscopy (AFM) is no longer used as a nanotechnology tool responsible for topography imaging. However, it is widely used in different fields to measure various types of material properties, such as mechanical, electrical, magnetic, or chemical properties. One of the recently developed characterization techniques is known as loss tangent. In loss tangent AFM, the AFM cantilever is excited, similar to amplitude modulation AFM (also known as tapping mode); however, the observable aspects are used to extract dissipative and conservative energies per cycle of oscillation. The ratio of dissipation to stored energy is defined as tanδ. This value can provide useful information about the sample under study, such as how viscoelastic or elastic the material is. One of the main advantages of the technique is the fact that it can be carried out by any AFM equipped with basic dynamic AFM characterization. However, this technique lacks some important experimental guidelines. Although there have been many studies in the past years on the effect of oscillation amplitude, tip radius, or environmental factors during the loss tangent measurements, there is still a need to investigate the effect of excitation frequency during measurements. In this paper, we studied four different sets of samples, performing loss tangent measurements with both first and second eigenmode frequencies. It is found that performing these measurements with higher eigenmode is advantageous, minimizing the tip penetration through the surface and therefore minimizing the error in loss tangent measurements due to humidity or artificial dissipations that are not dependent on the actual sample surface.


2013 ◽  
Vol 46 (23) ◽  
pp. 9396-9402 ◽  
Author(s):  
Donna C. Hurley ◽  
Sara E. Campbell ◽  
Jason P. Killgore ◽  
Lewis M. Cox ◽  
Yifu Ding

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