Optical microrheology using rotating laser-trapped particles

Abstract

We demonstrate an optical system that can apply and accurately measure the torque exerted by the trapping beam on a rotating birefringent probe particle. This allows the viscosity and surface effects within liquid media to be measured quantitatively on a micron-size scale using a trapped rotating spherical probe particle. We use the system to measure the viscosity inside a prototype cellular structure.

5 pages, 4 figures. v2: bibliographic details, minor text corrections

References in corpus (4)

• Optical alignment and spinning of laser-trapped microscopic particles
• Optical application and measurement of torque on microparticles of isotropic nonabsorbing material
• Optical measurement of microscopic torques
• Orientation of biological cells using plane-polarized Gaussian beam optical tweezers

Cited by in corpus (1)

• Opto-mechanical probes of resonances in amplifying microresonators