Zero applied stress rheometer

• DOI: 10.1063/1.1499210
• Publication Date: 2002-08-30T17:02:52Z
• Authors: L. Bellon; L. Buisson; S. Ciliberto; F. Vittoz
• Keywords: Thermal fluctuations; Oscillation (cell signaling)

In order to test the fluctuation-dissipation relation on rheological properties of soft materials, we built an experiment measure thermally excited strain in a sample and compare it classical response external stress. The rheometer is based cylindrical Couette geometry. We use differential interferometry achieve better than 10−10 rad/Hz sensitivity angular position above 0.5 Hz. forcing method, electrostatic interaction capacitor, generates torques comparable that thermal noise. Experiments calibrated silicon oil show good agreement between fluctuation measurements.