Viscosity sensing by adjusting the interface of a small liquid droplet/silica composite layer on quartz crystal microbalance

We report the different attenuated shear vibrations of hydrophilic quartz crystal microbalance (QCM) by attached small viscous liquids and this technique enabled us to measure the viscosity of various 5 μL solutions. Covering entire area of QCM surface by a liquid was important for stable damping time measurement and accordingly we induced silica/polyelectrolyte hydrophilic coating on QCM with using Layer by Layer (LbL) self assembly method for enhanced wettability and saving viscous materials. We examined the relationship between damping time and viscosity of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP) or glycerol aqueous solutions. We also applied this technique for estimating blood coagulation behaviors.