PIER Photon Science Colloquium: Microfluidics without walls

by Christian Riekel (ESRF, Grenoble)

Friday 18 Oct 2013, 14:00 → 15:00 Europe/Berlin

CFEL, Bldg. 99 (DESY Hamburg)

The ever increasing brilliance of synchrotron radiation sources and the availability of XFEL sources suggest exploring new approaches for probing ultrasmall liquid volumes by micro- and nanobeam techniques. I will provide in my talk an overview on several digital microfluidics approaches based on µL to pL droplets evolving in air or supported by a substrate with well-defined wetting properties. I will show that pL droplets generated by a drop-on-demand inkjet system can be probed stroboscopically by µSAXS techniques or can be precisely deposited on a substrate for initiating a chemical reaction. The coalescence of ballistic droplets in flight allows in principle studying conformational changes of macromolecules in solution without wall-effects. The development of artificial superhydrophobic substrates mimicking the Lotus effect is a promising approach for studying quasi contact-free droplets during evaporation until residue formation. I will show several examples related to materials of biological interest such as peptide self-assembly and biomineralization. Experiments reported have been principally performed at the ESRF-ID13 microfocus beamline.