Microsphere viscometers for low temperature applications

Abstract

We describe two types of viscometer utilizing metallic microspheres. These spheres are set into stationary translational motion or into translational oscillations. The motion of these charged microparticles is induced and detected via an electric field. The observed damping of the motion yields information on the dissipation mechanisms and the viscosity of the medium investigated. The advantages of our devices for low temperature use are a simple geometry, high resolution, low heat input into the sample and the small sample volume needed. The two viscometers are complementary to each other in the sense that one is applicable at high viscosities while the other is sensitive at low viscosities.