Displacing a fluid of interest in a capillary by placing it in train with a ferrofluid and using a magnetic field to move the ferrofluid

摘要

At least one ferrofluid train (3) is placed in the capillary (1) comprising a plug of ferrofluid with a liquid joined to one or both ends. This liquid is immiscible with the ferrofluid and with the fluid of interest, which is next to it. The fluid of interest is moved in the capillary by moving the ferrofluid using a magnetic field generated by a magnet (11) outside the capillary. At least one ferrofluid train (3) is placed in the capillary (1) comprising a plug of ferrofluid with a liquid joined to one or both ends. This liquid is immiscible with the ferrofluid and with the fluid of interest, which is next to it. The fluid of interest is moved in the capillary by moving the ferrofluid using a magnetic field generated by a magnet (11) outside the capillary. The ferrofluid is an ionic ferrofluid and the capillary has hydrophobic internal walls and a diameter of less than 1mm. A pre-wetting stage wets the internal walls of the capillary with oil before putting in the ferrofluid train. The immiscible liquid and the fluid of interest can be placed at both ends of the ferrofluid plug and there can be a number of ferrofluid plugs in the capillary, or a plug of immiscible liquid can separate two plugs of the fluid of interest. An Independent claim is also included for is a fluid displacement microsystem which includes a capillary (1) containing a ferrofluid train (3). Outside the capillary is a magnetic system (11) to move the ferrofluid in the capillary. The ferrofluid train comprises a plug of ferrofluid and an immiscible liquid at one or both ends as described above.