Magnetically actuated fluid handling devices for microfluidic applications

A method for moving fluid in a fluid handling device having at least one fluid inlet and at least one fluid outlet comprising the steps of:

• providing a plurality of microsized flow channels, each channel, being in fluid communication with at least one fluid inlet and at least one fluid outlet, wherein at least one channel branches off from another channel;
• providing one or more slugs of magnetic fluid located within at least one of the flow channels, a slug being either held stationary or moved by at least one magnet and wherein at least one of the slugs comprises a ferrogel;
• and
• using at least one magnet to move a slug through the flow channel causing a net flow of fluid into the fluid inlet and a net outflow of fluid out of the fluid outlet.

A fluid handling device comprising:

• at least one microsized flow channel forming a loop, the flow channel being in fluid communication with at least a first fluid inlet and at least a last fluid outlet;
• at least a first and second slug of magnetic fluid;
• both located within the flow channel;
• at least one magnet arranged and adapted so as to control said first slug to move within said flow channel;
• wherein, the volune of said first slug is less than the volume between a most closely-spaced fluid inlet and outlet of said device;
• at least one magnet arranged and adapted so as to control said second slug in a stationary position between the first fluid inlet and the last fluid outlet;
• wherein, the volune of the stationary slug is less than the volume between the first fluid inlet and the last fluid outlet on either side of the slug.

A method for moving a fluid in a microfluidic device comprising the steps of:

• providing in the microfluidic device a microsized flow channel forming a loop, the flow channel being in fluid communication with one or more fluid inlets and outlets wherein there is at least one first fluid inlet and at least one last fluid outlet;
• forming at least two slugs of a magnetic fluid material located within the flow channel;
• using at least one magnet to hold at least one slug stationary between the first fluid inlet and the last fluid outlet so that fluid in the loop cannot flow from the last fluid outlet to the first fluid inlet;
• and
• using at least one magnet to move at least one slug around the flow channel loop, thereby causing a net inflow of fluid into the fluid inlet and a net outflow of fluid out of the fluid outlet.