Sound-controlled fluidic processor.

Precision processing of various liquids while maintaining their purity holds immense potential for many applications. However, liquids tend to leave residues that contaminate handling tools and compromise volumetric precision, necessitating contactless strategies to prevent liquid loss. Biological and chemical samples carried by fluids can be sensitive to physical stimuli, demanding mild but effective means to preserve integrity. Here, we report a sound-controlled fluidic processor for complete and well-controlled microfluidic functions, including moving, merging, mixing, and cleaving, in contactless and harmless manners. The processor generates an acoustophoretic force field that serves as a versatile toolbox for manipulating droplets with surface tension from 17.9 to 72 millinewtons per meter and volume from 1 nanoliter to 3 milliliters, offering a wealth of operations crucial to fundamental biomedical and chemical practices.