Abstract
We present a numerical method based on the linear elastic membrane theory to compute the morphological deformation of a spherical cell from the photonics stress distribution over the cellular membrane. The method is applied to fit the experimental data for deformation of a spherical human red blood cell trapped and stretched in a fiber-optical dual-beam trap with a single fitting parameter Eh where E is the Young's modulus of elasticity and h is the thickness of the cell membrane. We obtained Eh = (20+/-2)muNm(-1) which is comparable to results reported earlier. This numerical method can be applied in general experimental conditions.
Highlights
Dual-beam optical stretchers consisting of two counter-propagating and slightly diverging laser beams from two well-aligned single-mode optical fibers have been used for noninvasive and non-contact trapping and stretching of biological cells to measure their viscoelastic properties [1,2,3]
A more general calculation taking into consideration the laser beam divergence and its Gaussian intensity profile has been reported recently [2], by which the optical stress distribution over the cellular surface can be calculated for different distances between the cell and the fiber endfaces and different numerical apertures of the fibers
We verified that in the special case when the stress distribution is given by σ r = σ 0 cos2 (φ), the deformation obtained by our numerical method is identical to that obtained from the semi-analytical solution in Ref. 1
Summary
Dual-beam optical stretchers consisting of two counter-propagating and slightly diverging laser beams from two well-aligned single-mode optical fibers have been used for noninvasive and non-contact trapping and stretching of biological cells to measure their viscoelastic properties [1,2,3]. The method is more general in the sense that it is applicable to various value of W/R in the dual-beam optical stretcher and to any other stress distribution, including the cases where the stress distribution can not be represented by analytical expressions We apply this model to fit the experimental data for measurement of the deformation of a spherical human red blood cell (RBC) trapped and stretched in a fiber-optical dual-beam stretcher with a single fitting parameter Eh where E is the Young’s modulus of elasticity and h is the thickness of the cell membrane. The experimental data taken with the spherical RBCs allowed us to check the validity of our linear elastic membrane model in simple geometry and to modify the mechanical model for future applications with the compliant biconcave geometry
Sign-in/Register to view highlights & summary 
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call