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