System and method for droplet formation and manipulation using ferrofluids

A microfluidic device for delivering a drug to a subject comprising:

• a ferrofluid reservoir disposed in the microfluidic device and containing a ferrofluid and/or drug therein;
• a continuous-phase reservoir disposed in the microfluidic device and containing an oil phase therein, the continuous-phase reservoir containing a permeable membrane therein through which the ferrofluid and/or drug passes;
• one or more microfluidic channels connecting between the ferrofluid reservoir and the continuous-phase reservoir;
• and
• a first permanent magnet or electromagnet disposed adjacent to a first side of the microfluidic device and configured to form droplets of ferrofluid and/or drug within the continuous-phase reservoir.

A method of delivering a ferrofluid and/or drug to a subject comprising:

• positioning a microfluidic device on or within a subject, the microfluidic device comprising:
• a ferrofluid reservoir disposed in the microfluidic device and containing a ferrofluid and/or drug therein;
• a continuous-phase reservoir disposed in the microfluidic device and containing an oil phase therein, the continuous-phase reservoir containing a permeable membrane therein through which the ferrofluid and/or drug passes;
• and
• one or more microfluidic channels connecting between the ferrofluid reservoir and the continuous-phase reservoir;
• and
• applying a first magnetic field to the microfluidic device to generate droplets comprising the ferrofluid and/or drug;
• and
• applying a second magnetic field to the microfluidic device to transport the generated droplets across the permeable membrane and in contact with the subject.