TY - JOUR

T1 - In situ viscometry by optical trapping interferometry

A1 - Guzmán,C.

A1 - Flyvbjerg,Henrik

A1 - Köszali,R.

A1 - Escoffet,C.

A1 - Forró,L

A1 - Jeney,S.

AU - Guzmán,C.

AU - Flyvbjerg,Henrik

AU - Köszali,R.

AU - Escoffet,C.

AU - Forró,L

AU - Jeney,S.

PB - American Institute of Physics

PY - 2008

Y1 - 2008

N2 - We demonstrate quantitative in situ viscosity measurements by tracking the thermal fluctuations of an optically trapped microsphere subjected to a small oscillatory flow. The measured power spectral density of the sphere's positions displays a characteristic peak at the driving frequency of the flow, which is simply proportional to the viscosity, when measured in units of the thermal power spectral density at the same frequency. Measurements are validated on different water-glycerol mixtures, as well as in a glycerol gradient, where no a priori knowledge of the solution is used to determine the glycerol concentration.

AB - We demonstrate quantitative in situ viscosity measurements by tracking the thermal fluctuations of an optically trapped microsphere subjected to a small oscillatory flow. The measured power spectral density of the sphere's positions displays a characteristic peak at the driving frequency of the flow, which is simply proportional to the viscosity, when measured in units of the thermal power spectral density at the same frequency. Measurements are validated on different water-glycerol mixtures, as well as in a glycerol gradient, where no a priori knowledge of the solution is used to determine the glycerol concentration.

KW - FORCES

KW - TWEEZERS

KW - PARTICLE

KW - VISCOSITY

KW - TRACKING

UR - http://link.aip.org/link/APPLAB/v93/i18/p184102/s1

U2 - 10.1063/1.3020713

DO - 10.1063/1.3020713

JO - Applied Physics Letters

JF - Applied Physics Letters

SN - 0003-6951

IS - 18

VL - 93

SP - 184102

ER -