<title>Dielectro-deformational spectroscopy of erythrocytes</title>

Optical Diagnostics of Mechanical Properties of Red Blood Cells based on the Deformation by High Frequency Electric Field

“…It was believed that the principal sources of elastic stress that arise in the course of dielectro deformation of erythrocytes, were the shear deformations of the membrane. 5,6,8,10 One of the most important results of this work is the revision of this concept. It is shown that the dielectrodeformation process of erythrocytes is determined by a combination of bending and shear elastic stresses of comparable strength that arise in the erythrocyte membrane.…”

“…As a result, the stationary dielectro deformations depend on two elastic moduli of the membrane, bending elastic modulus K c and shear elastic modulus , while the dynamic deformations depend on four moduli: two elastic, K c and , and two viscous, membrane surface viscosity s and hemoglobin solution viscosity i . Compared to a single parameter describing the static, and two parameters, and s , describing the dynamic deformations reported in previous theories, 5,6,8,10 it means that there are numerous complications in the data evaluation procedures in the dielectro-deformational technique. It also necessitates re-interpretation and re-evaluation of the previously measured data 6,8 regarding the influence of various factors on mechanical moduli.…”

“…(6) The bending stiffness force F b was not even considered in the previous theories reported. 6,10 It was supposed a priori that the cell elongation in the electric field is too large to be supported by bending deformation of the membrane; hence, it is due completely to shear deformation. However, the phasecontrast cell images presented in Figure 2 of Ref.…”

“…Using this approximation, it is possible to derive a rather simple analytical equation of dielectro deformations, and even obtain analytical solutions (for static and for some dynamic deformations). 8,10 In this article this approach is used to incorporate the analysis of bending deformation of an erythrocyte membrane into theory, and to obtain the general dynamic equation of dielectro deformations. The theory is verified by comparing it with existing experimental results both on static and dynamic dielectro deformation of erythrocytes.…”

“…Such possibilities are offered by a novel technique-the optically registered dielectro deformation of cells. [5][6][7][8][9][10] The technique is based on a fundamental physical phenomenon: a polarizable body, surrounded by a less polarizable medium, tends to become elongated in the direction of the electric field applied. The elongation is quadratic in field strength, because the acting force is proportional to the product of the field strength and the density of the polarization charge induced, the latter also being proportional to the field strength.…”