6th Annual Symposium
Physics of Cancer
September 7-9, 2015
|PoC - Physics of Cancer - Annual Symposium|
Optical stretching forces revisited
Division for Biomedical Physics, Medical University of Innsbruck, Müllerstraße 44, A-6030 Innsbruck, Austria
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Optical forces acting on soft biological cells are able to induce measurable deformations. Since diseased cells often show an altered mechanical response to optical stretching forces, this can be used for diagnostic purposes in micro-fluidic devices. In order to optimize the stretching effect, it is important to understand its origins. Shape changes of the soft particle affect the intensity distribution by altering refraction (or scattering) - and thus change the optical forces themselves, therefore a self-consistent treatment is inevitable.
A simple consistent model in 1D will be discussed, which provides some insight into the origin of the forces in the “optical stretcher”, in particular on the role radiation pressure forces and gradient forces play and on their relative importance.
Finally a brief summary on some recent developments on dual beam traps with the capability to trap very large (~100µm) specimens and with a huge (~1mm3) volume accessible to optical manipulation will also be given.