Viscous drag effect in the flexural rigidity and cantilever stiffness of bio- and nano-filaments measured with the shooting-bead method.
The so-called shooting-bead method is a fast and easy experimental technique for evaluating cantilever stiffness and flexural rigidity of semiflexible to semirigid rodlike biological and nano-filaments based on the measurement of just two distances. In this paper we have derived the shooting-bead formula for cantilever stiffness and flexural rigidity taking into account the effects of the viscous drag force exerted on the filament itself. To this end, we have defined a key variable, called the filament energy-loss factor (or filament drag factor), which accounts for all the energy-loss effects. It has been shown that due to the logarithmic dependence of the filament energy-loss factor on the radius and the length of the filament, inclusion of this factor in the formula for the flexural rigidity has a very noticeable effect on the result even for very thin or long filaments. It has also been shown that the effect due to the consideration of filament energy-loss factor on calculation of the flexural rigidity increases with increasing the flexibility of the filament. We have also considered various sources of experimental error and estimated their effects.
Samarbakhsh
Abdorreza
A
Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta, Canada T6G 2G7. asamar@phys.ualberta.ca
Tuszynski
Jack A
JA
D001696:Biomechanical Phenomena; D002138:Calibration; D004548:Elasticity; D008863:Microspheres; D008870:Microtubules / Q000737:chemistry* / Q000378:metabolism*; D008954:Models, Biological; D009038:Motion; D036103:Nanotechnology; D037742:Nanotubes, Carbon / Q000737:chemistry; D012015:Reference Standards; D014783:Viscosity
D037742:Nanotubes, Carbon