Viscoelasticity and Dielectric Measurement of Small Sample Volume for Diagnostic Platform of Synovial Fluid

The synovial fluid is found in joints of vertebrates and contains a high molecular weight polysaccharide (hyaluronan) acting as a modifier to ensure proper lubrication. Both, its concentration and molecular weight are subject to pathological alterations in certain diseases. Laboratory analysis of physical properties is difficult because of the limited amount of sample volume (usually below 100 μl). We present a sensor platform which requires volumes below 10 μl to measure the viscoelastic properties in the kilohertz range and the electrochemical impedance spectrum (EIS) from 102 to 106 Hz. Two electrodynamic acoustic shear wave transducers are used to measure both the single-sided viscoelastic shear impedance and the transmission of shear waves. The same elements are used as electrodes for measuring the EIS with a precision impedance analyser. The device is supposed to be used for clinical diagnosis and therapy tracking.