Disclosed is a centrifugal microfluidic device comprising a piezoelectric substrate; a rotatable platform device on the substrate; and at least one transducer on the substrate, the transducer being configured to generate a surface acoustic wave that propagates on the surface of the substrate and contacts the rotatable platform device asymmetrically to transfer energy thereto with a lateral distribution to cause rotation of the rotatable platform device. The device may be a microfluidic valve, a microfluidic mixer or a microfluidic particle concentrator.

A fluid handling device has fluidic structures having inlet and outlet chambers and a connecting duct fluidically connecting the two. In a first state, the inlet chamber is completely or partly filled with at least a liquid and partly filled with a compressible medium, and the outlet chamber is at least partly filled with the compressible medium. One of the inlet chamber and the outlet chamber has such a venting duct that a flow resistance/volume product of venting of the chamber for the compressible medium amounts to at least 6700 N.Math.s/m.sup.2, the other of the inlet chamber and of the outlet chamber being vented. An actuator for actuating the fluidic structures is to cause a pressure difference of at least 30 Pa between the compressible media within the inlet and outlet chambers, so as to thereby switch a valve device implemented into the connecting duct.

The invention relates to a microfluidic system for processing biological samples comprising a holding chamber adapted for holding a fluid and to be rotated on a platform, said holding chamber comprising an outlet through which fluid flow is controlled by an acceleration-primed valve system, wherein the acceleration-primed valve system comprises a capillary valve and an outlet channel. The invention provides a novel valving system, which retains fluids at low angular velocities, removes the need for hydrophilic surfaces, minimizes disc real-estate and optimizes certain microfluidic processes done in the holding chamber.

A microfluidic valve provided herein is configured to mix or capable of mixing a sample and/or a reagent in addition to controlling liquid flow. In one embodiment, the microfluidic valve comprises a rotor (3) and one or more micro-structures (2) that move with the rotation of the rotor (3). In one embodiment, the one or more micro-structures (2) stir and/or mix content in a mixing chamber (5) formed by the rotor (3), a base (1), and a sleeve (4) of the microfluidic valve. A microfluidic chip or chip system comprising one or more of the microfluidic valves, and methods of use, are also provided.

A centrifuge unit for a microfluidic device for processing liquid samples includes a centrifuge cup and at least one centripetal force-dependent valve function.