| AVS 54th International Symposium | |
| MEMS and NEMS | Monday Sessions |
| Session MN-MoA |
| Session: | Materials Processing, Characterization and Fab Aspects |
| Presenter: | G. Hähner, University of St Andrews, Scotland, UK |
| Authors: | G. Hähner, University of St Andrews, Scotland, UK N. McLoughlin, University of St Andrews, Scotland, UK S.L. Lee, University of St Andrews, Scotland, UK |
| Correspondent: | Click to Email |
The density and the viscosity are important parameters for the understanding and tailoring of many processes taking place in liquids. Their determination is generally performed with macroscopic liquid amounts and in separate measurements. In recent years some approaches have been proposed to determine these properties simultaneously. The majority of the methods applied still requires macroscopic liquid volumes and is based on macroscopic techniques. With the growing interest in microfluidic applications, however, alternative approaches for the determination of liquid properties on the microscale are desirable. We present a method for determining the viscosity and density of small liquid volumes (microliters) simultaneously from the resonance spectra of both magnetically driven as well as thermally excited microcantilevers.1 Parameters characteristic of the resonance behavior of the system were extracted from resonance spectra recorded in a liquid of known density and viscosity. Subsequently, these parameters were used to determine the properties of further samples. In addition, temperature dependent spectra were exploited to extract the activation energy of viscous flow. The procedure we present is fast and reliable and requires no calibration of the cantilever force constant or specific knowledge of the cantilever geometry. Based around existing AFM technology the approach we propose can be easily adapted to suit a variety of microfluidic applications.
1 N. McLoughlin, S. L. Lee, G. Hähner Appl. Phys. Lett. 89, 184106 (2006).