Dr. Natan Osterman: Thermal Optofluidics

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Povzetek:

    Thermal Optofluidics

    Dr. Natan Osterman, Institut Jožef Stefan, Ljubljana & LPKF Laser & Elektronika d.o.o., Naklo

Optofluidics is an emerging field that synergizes optics and microfluidics to benefit from the specific advantages of both disciplines. On one side, microflows can carry analytes and optically active materials with refractive index adjustable in real time. The flows can also make very good waveguides with optically smooth interfaces. On the other side, light can be used to precisely drive the fluid on a microscale, enabling previously inaccessible regimes of tiny volumes and closed flow paths.

In my talk, I will present our recent optofluidic experiments. I will start with so called thermal broom, a mechanism in which a combination of thermophoresis and optically induced fluid flows (thermoviscous pumping) gives rise to a thermal trap for microparticles and biomolecules. Such thermal broom can, for example, 60-fold concentrate dsDNA from surrounding liquid within seconds. In the second part of the talk I will  focus to optically induced thermoviscous pumping in nematic liquid crystals (LC) where laser scanning not only creates flows, but also results in the reorientation of molecules. I will discuss the possibility of using this mechanism for all-optical routing of light. I will conclude the talk with two "classical" optofluidic experiments: a simple optofluidic color filter/attenuator based on LC flows and tunable cholesteric LC laser.