Matthias Wassermeier

Flat fluidics: a new route toward programmable biochips

The miniaturization of chemical and biological processes has made enormous progress driven mainly by genomics and proteomics. Microfluidics is the core technology to realize miniaturized laboratories with feature sizes on a submillimeter scale. Here, we report on a novel microfluidic technology which allows biochips to be programmed so that different biological assays can be performed with only one chip layout. Interdigital transducers integrated on piezoelectric substrates excite surface acoustic waves (SAW) which drive reagents on the surface of the biochip. The reagents can be placed on any desired spot on the chip’s surface, they can be merged, split and brought to reaction. SAW technology can also be used to efficiently agitate small volumes of liquids accelerating diffusion limited reactions considerably.

Acoustic ‘Distributed Source’ Mixing of Smallest Fluid Volumes

Acoustically driven mixing of small fluid volumes is reported. Using surface acoustic waves on a mixer chip and employing wave guiding effects in a substrate enables us to distribute a set of “virtual sources” for acoustic streaming over large areas. We demonstrate the applicability of our mixing technique to microarray applications, for mixing of individual wells in a micro titer plate, and other state-of-the-art hybridization assays.