A device for the mixing fluid media. The device is a bladeless mixer. The device comprises a hollow body with at least a single inlet opening in its bottom and at least a single outflow region in its side. The device is rotated at a speed at which the media due to centrifugal forces enters the device's hollow cavity via the inflow opening or unit. The media is discharged from the cavity through one or more outlet units or openings in the sides or in the top of the device. During mixing the media does not rise above the level of the undisturbed media.

A device for the mixing fluid media. The device is a bladeless mixer. The device comprises a hollow body with at least a single inlet opening in its bottom and at least a single outflow region in its side. The device is rotated at a speed at which the media due to centrifugal forces enters the device's hollow cavity via the inflow opening or unit. The media is discharged from the cavity through one or more outlet units or openings in the sides or in the top of the device. During mixing the media does not rise above the level of the undisturbed media.

A microfluidic device and method is provided for concentrating particles in a fluid sample. The microfluidic device has a chamber, wherein the chamber has a filtering unit defining a first compartment and a second compartment, the first compartment being in fluid communication with the second compartment and being for receiving a fluid sample containing particles, the filtering unit being configured to selectively retain particles of the fluid sample based on a size of the particles, at a sub-region of the first compartment as the fluid sample flows from the first compartment to the second compartment; and an acoustic transducer configured to generate acoustic waves in the sub-region to disperse the particles.