Nanoliter liquid characterization by open whispering-gallery mode dielectric resonators at millimeter wave frequencies
- 1 October 2008
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 104 (7), 074111
- https://doi.org/10.1063/1.2991182
Abstract
We present an approach for identification and concentration determination of liquids of pico to nanoliter volumes at a frequency of 35 GHz based on a whispering-gallery mode (WGM) dielectric resonator technique. A quasioptical coupling scheme based on dielectric image waveguides was employed to excite high- running wave WGMs with uniform azimuthal field distribution in cylindrical sapphire disks with quality factors up to at room temperature. Measurement of the liquid induced changes in the resonator quality factor and resonance frequency has been performed for droplets down to 90 pl volume spotted at different positions on the surface of the sapphire disk. We have employed our method for concentration determination of ethanol, glucose, and albumin dissolved in water. Solutions with concentration values well below 10% could be clearly separated from pure water. Our method is promising for the characterization of biological liquids.
Keywords
This publication has 24 references indexed in Scilit:
- Two-layered disc quasi-optical dielectric resonators: electrodynamics and application perspectives for complex permittivity measurements of lossy liquidsMeasurement Science and Technology, 2007
- Dielectric properties of glucose solutions in the millimetre-wave range and control of glucose content in bloodMeasurement Science and Technology, 2007
- Reference liquids for the calibration of dielectric sensors and measurement instrumentsMeasurement Science and Technology, 2007
- Permittivity of Pure Water, at Standard Atmospheric Pressure, over the Frequency Range –25THz and the Temperature Range –100°CJournal of Physical and Chemical Reference Data, 2007
- Permittivity measurement of low and high loss liquids in the frequency range of 8 to 40 GHz using waveguide transmission line techniqueMicrowave and Optical Technology Letters, 2005
- Broadband coaxial cavity resonator for complex permittivity measurements of liquidsIEEE Transactions on Instrumentation and Measurement, 2000
- Protein-Water Interactions Determined by Dielectric MethodsAnnual Review of Physical Chemistry, 1992
- Broadband complex permittivity measurements by time-domain spectroscopyIEEE Transactions on Instrumentation and Measurement, 1990
- Low-Loss Rectangular Dielectric Image Line for Millimeter-Wave Integrated CircuitsIEEE Transactions on Microwave Theory and Techniques, 1978
- An improved model for the dielectric constant of sea water at microwave frequenciesIEEE Transactions on Antennas and Propagation, 1977