Erythrocyte deformation in high-throughput optical stretchers.
Optical stretchers can be used to quantify elastic and homeostatic properties of cells. Because they can apply forces to cells without requiring direct contact, they may noninvasively measure mechanical properties related to cell and membrane health. Present-day optical stretchers are, however, limited to measurements on individual stationary cells, limiting throughput. To overcome this limitation and allow study of variations in cell populations, we recently developed and tested a microfluidic chamber that measures optical stretching parameters for erythrocytes under dynamic flowing conditions. The method uses a single linear diode laser bar and permitted measurements at low flow rates and higher throughput. Here, we numerically investigate the feasibility of further increasing the measurement rates of the optical stretcher in parameter domains where hydrodynamic and optical forces are of comparable magnitude. To do this we couple a recently implemented dynamic optical ray-tracing technique with a fluid-structure interaction solver to simulate the deformation of osmotically swollen erythrocytes in fluid flow of variable rate. Our results demonstrate that a detectable steady-state stretch is induced at nominal optical powers and flow rates. In addition, we find that flow rates can be increased significantly with no major effect on net cell stretch showing the feasibility of application of this technique at greatly increased throughputs.
Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, Maryland 21250, USA.
Ihab
I
Sraj
Alex C
AC
Szatmary
Sanjay A
SA
Desai
David W M
DW
Marr
Charles D
CD
Eggleton
D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004912:Erythrocytes / Q000502:physiology*; D005434:Flow Cytometry / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D052898:Optical Tweezers; D013718:Tensile Strength / Q000502:physiology