title: 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.
authors.affiliation: Centre for Biophotonics and Laser Science, Department of Physics, The University of Queensland, Brisbane QLD 4072, Australia. A.I.Bishop@hw.ac.uk
authors.forename: Alexis I
authors.initials: AI
authors.lastname: Bishop
authors.forename: Timo A
authors.initials: TA
authors.lastname: Nieminen
authors.forename: Norman R
authors.initials: NR
authors.lastname: Heckenberg
authors.forename: Halina
authors.initials: H
authors.lastname: Rubinsztein-Dunlop
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry; D004058:Diffusion; D055095:Optics and Photonics; D012212:Rheology / Q000379:methods*; D019415:Torque; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D002119:Calcium Carbonate