Abstract: A microfluidic system employs a microchannel and a gravity driven pump comprising horizontally oriented fluid supply reservoirs which supplies fluid to the microchannel at a substantially constant rate. The device is useful for numerous microfluidic applications, for example in the culture and/or treatment of biological systems under constant flow-induced stress, cell-size sorting, motile sperm sorting, or embryo culture.

Abstract: The invention relates to a dispersing device wherein the dispersed material has a variable throughput comprising a jet disperser which comprises at least one inlet for the materials to be dispersed, a chamber with a multiciplicity of openings arranged in rows along the chamber wall, which lead into an outlet chamber, and an outlet for the finally dispersed material, wherein the chamber comprises a displaceably mounted piston which, depending on its position within the chamber, partially or completely shuts off a specific number of the openings for the passage of the flow os dispersed material.