Manipulation of high-density materials, such as crystals and liquid condensates, is of great importance for many applications, including serial crystallography, structural and molecular biology, chemistry, and medicine. In this work, we describe an acoustic technique to focus and harvest flowing crystals and liquid condensates. Moreover, we show, based on numerical simulations, that the acoustic waves can be used for size-based particle (crystals, droplets, etc.) separation. This is an essential technological step in biological research, medical applications, and industrial processes. The presented technology offers high precision, biocompatibility, ease of use and additionally, is non-invasive and inexpensive. With the recent advent of X-ray Free Electron Laser (XFEL) technology and the associated enormous importance of a thin jet of crystals, this technology might pave the way to a novel type of XFEL injector.
