System and method for droplet formation and manipulation using ferrofluids
A microfluidic device for forming droplets includes at least one ferrofluid reservoir disposed in the microfluidic device and containing a ferrofluid therein. The microfluidic device includes a continuous-phase reservoir disposed in the microfluidic device and containing an oil phase therein and one or more microfluidic channels connecting between the at least one ferrofluid reservoir and the continuous-phase reservoir, the continuous-phase reservoir comprising a step region having an increased height as compared to a height of the one or more microfluidic channels. To form droplets an externally applied magnetic field is applied to the device to pull the ferrofluid into the continuous-phase reservoir, whereby droplets are formed at step region.
1. An implantable 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, the continuous-phase reservoir comprising a step region having an increased height as compared to a height of the one or more microfluidic channels;
a permanent magnet disposed adjacent to the permeable membrane on a first side of the device; and
an electromagnet disposed on a second side of the device and connected to driver circuitry configured to power the electromagnet.
2. The implantable microfluidic device of claim 1 , further comprising a wireless controller, wherein the wireless controller controls operation of the electromagnet.
3. The implantable microfluidic device of claim 2 , wherein the wireless controller actuates the electromagnet for one or more preset time intervals.
4. The implantable microfluidic device of claim 1 , wherein the electromagnet is connected to driver circuitry and an internal power source.
5. The implantable microfluidic device of claim 1 , wherein the ferrofluid comprises the drug.
6. The implantable microfluidic device of claim 1 , wherein the drug is conjugated to magnetic nanoparticles in the ferrofluid.
7. The implantable microfluidic device of claim 1 , wherein the ferrofluid is mixed with the drug.
8. 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.
9. The microfluidic device of claim 8 , further comprising a second permanent magnet or electromagnet disposed adjacent to a second, opposing side of the microfluidic device and configured to pull the droplets of ferrofluid and/or drug across the permeable membrane.
10. The microfluidic device of claim 8 , wherein the permable membrane of the microfluidic device is positioned adjacent to the skin of a subject.
11. The microfluidic device of claim 8 , wherein the ferrofluid comprises the drug.
12. The microfluidic device of claim 8 , wherein the drug is conjugated to magnetic nanoparticles in the ferrofluid.
13. The microfluidic device of claim 8 , wherein the ferrofluid is mixed with the drug.
14. The microfluidic device of claim 8 , wherein the continuous-phase reservoir comprises a step region having an increased height as compared to a height of the one or more microfluidic channels.
15. 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.
16. The method of claim 15 , wherein the first and/or second magnetic fields are applied with a permanent magnet.
17. The method of claim 15 , wherein the first and/or second magnetic fields are applied with a permanent magnet.