Microfluidic devices on glass for liquid mixtures concentration with coupled Thz sensor


  • Salomao Moraes da Silva Junior Unicamp
  • Johan Stiens Vrije Universiteit of Brussels - VUB
  • Stanislav Moshkalev Unicamp
  • Jacobus Willibrordus Swart Unicamp
  • Roberto Lacerda de Orio Unicamp
  • Vladimir Matvejev Vrije Universiteit of Brussels - VUB
  • Yuchen Zhang Vrije Universiteit of Brussels - VUB
  • Werner Vandermeiren Vrije Universiteit of Brussels - VUB
  • Cathleen De Tandt Vrije Universiteit of Brussels - VUB




Microfluidic device; Passive Micromixer; Laminar flow; THz sensor; Ethanol concentration; Linear control of ethanol con-centration.


This paper reports on the performance of a sub-THz liquid sensor tool coupled to a microfluidic platform. Non-invasive, non-destructive and on-line measurements are demonstrated for the determination of ethanol concentration and for controlling via micromixer device. We have developed a label-free chemical sensing methodology coupling a sub-terahertz sensor technology in microfluidic devices fabricated on glass and polydimethylsiloxane. The concept of sensor in micromixer applications operating at 60 GHz for known ethanol concentration ranging 0% to 100%, with a corresponding dynamic range of 2.79dB. The sensor allowed establishing the correlation between the mass flow rate and the ethanol concentration in the microfluidic system, where two-stream lines form the mixture in laminar flows, with Reynolds number < 13.54 and Peclet number > 25700. We demonstrated on-line sensing and linear control of ethanol concentration on demand with a small variation of 0.32% (v/v) between measured and required ethanol concentration.