PIER Photon Science Colloquium: Microfluidics without walls

by Christian Riekel (ESRF, Grenoble)

Friday, October 18, 2013 from to (Europe/Berlin)
at DESY Hamburg ( CFEL, Bldg. 99 )
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.