Automated high-throughput viscosity and density sensor using nanomechanical resonators
| Autor: | Thomas Braun, Benjamin A. Bircher, Roger Krenger |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Cantilever
Microfluidics Analytical chemistry High-throughput 02 engineering and technology 01 natural sciences Phase-locked loop Viscosity Resonator Materials Chemistry Electrical and Electronic Engineering Instrumentation Resonant microcantilevers Liquid Two-phase microfluidics Signal processing Millisecond business.industry Chemistry Reduced order model 010401 analytical chemistry Metals and Alloys Resonance 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Electronic Optical and Magnetic Materials Surfaces Coatings and Films Mass density Optoelectronics Hydrodynamic model 0210 nano-technology business Excitation |
| Zdroj: | SENSORS AND ACTUATORS B-CHEMICAL Sensors & Actuators: B. Chemical |
| ISSN: | 0925-4005 |
| DOI: | 10.1016/j.snb.2015.09.084 |
| Popis: | Most methods used to determine the viscosity and mass density of liquids have two major drawbacks: relatively high sample consumption (∼milliliters) and long measurement time (∼minutes). Resonant nanomechanical cantilevers promise to overcome these limitations. Although sample consumption has already been significantly reduced, the time resolution was rarely addressed to date. We present a method to decrease the time and user interaction required for such measurements. It features (i) a droplet-generating automatic sampler using fluorinated oil to separate microliter sample plugs, (ii) a PDMS-based microfluidic measurement cell containing the resonant microcantilever sensors driven by photothermal excitation, (iii) dual phase-locked loop frequency tracking of a higher-mode resonance to achieve millisecond time resolution, and (iv) signal processing to extract the resonance parameters, namely the eigenfrequency and quality factor. The principle was validated by screening series of 3 μL droplets of glycerol solutions separated by fluorinated oil at a rate of ∼6 s per sample. An analytical hydrodynamic model (Van Eysden and Sader, 2007 [6] ) and a reduced order model (Heinisch et al., 2014 [16] ) were employed to calculate the viscosity and mass density of the sample liquids in a viscosity range of 1–10.5 mPa s and a density range of 998–1154 kg m −3 . |
| Databáze: | OpenAIRE |
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