Picoliter rheology of gaseous media using a rotating optically trapped birefringent microparticle

Yoshihiko Arita, Andrew W. McKinley, Michael Mazilu, Halina Rubinsztein-Dunlop, Kishan Dholakia

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An optically trapped birefringent microparticle is rotated by a circularly polarized beam in a confined gaseous medium. By recording the terminal rotation velocity and the change in polarization of the incident trapping beam, we determine the viscosity by probing a picoliter volume of air, carbon dioxide, and argon in the vicinity of the microparticle. We also characterize the optical force acting on a trapped particle in air using the generalized Lorenz-Mie theory taking into account the aberrations present. This opens up a new potential application of optical tweezers for the accurate measurement of gas viscosity in confined geometries.

Original languageEnglish
Pages (from-to)8855-8858
Number of pages4
JournalAnalytical Chemistry
Issue number23
Publication statusPublished - 2011 Dec 1


All Science Journal Classification (ASJC) codes

  • Analytical Chemistry

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