Thermo-liquid crystal (TLC) thermography for the 3D temperature characterization of liquid microflows
The field of microfluidics is growing exponentially as is its impact in modern industrial applications ranging from the pharmaceutical/medical sector, to consumer electronics, reaching all the way to aerospace and large scale machinery. A great amount of such microfluidics applications, involve heat transfer solutions which employ sophisticated microfluidic devices with complex geometries and flow structures. However, all these innovations have been developed in the absence of an experimental time-resolved means of simultaneously characterizing the 3D velocity and temperature fields of the flow that runs through the microfluidic chips. The ability to understand the flow with this degree of precision will empower scientist and engineers to correct mistakes and device failures before they happen and save substantial costs in development of complex designs.The aim of this research project is to further develop the thermo-liquid crystal (TLC) thermography measurement technique in order to materialize the long awaited simultaneous 3D reconstruction of temperature and velocity fields in liquid flows. Over the last few years, the foundation of the method has been laid out, but further improvements in the fabrication of the TLC particles, acquisition hardware and software, color evaluation algorithms and calibration procedures are necessary to bring the technique to the point where flows in real industrial and scientific applications can be measured reliably. Furthermore, critical questions regarding the nature and color response of the TLC materials, which have remained unanswered for many years, will also be assessed but also the time response of their color signal and the effect of strong shear forces on their color will be examined.
 
Person in charge:
  • N.N. 
 
Funder:
  • German Research Foundation (DFG)
 
Publications:
  • Massing J, Kaden D, Kähler CJ, Cierpka C (2016) Luminescent two-color tracer particles for simultaneous velocity and temperature measurements in microfluidics. Measurement Science and Technology 27:115301
  • Baczyzmalski D, Weier T, Kähler CJ, Cierpka C (2015) Near-wall measurements of the bubble-and Lorentz-force-driven convection at gas-evolving electrodes. Experiments in Fluids 56:162
  • Segura R, Rossi M, Cierpka C, Kähler CJ (2015) Simultaneous three-dimensional temperature and velocity field measurements using astigmatic imaging of non-encapsulated thermo-liquid crystal (TLC) particles. Lab on a Chip 15:660-663
  • Segura R, Cierpka C, Rossi M, Joseph S, Bunjes H, Kähler CJ (2013) Non-encapsulated thermo-liquid crystals for digital particle tracking thermography/velocimetry in microfluidics. Microfluidics and Nanofluidics 14:445-456