Integrated modular on-chip droplet microfluidic screening platform

1 . A droplet microfluidic platform comprising:

a plurality of substrate layers, and

a plurality of functional components,

wherein the plurality of substrate layers is configured such that, when the plurality of substrate layers are stacked, one or more of the plurality of functional components is collectively formed within two or more of the plurality of substrate layers, the functional components comprising:

at least one droplet generator for continuous generation of cell-encapsulated droplets;

at least one merging mechanism configured to merge the cell-encapsulated droplets;

at least two incubation chambers for on-chip incubation of the cell-encapsulated droplets;

at least a first valve for trapping or releasing the cell-encapsulated droplets;

a detection mechanism; and

a second valve configured to direct the cell-encapsulated droplets from a first of the at least two incubation chambers to a second of the at least two incubation chambers;

at least one fluid passage to connect the functional components;

wherein the platform is capable of continuous/semi-continuous on-chip operation in a first-in first-out manner, wherein the platform comprises a sandwich design, wherein the at least two incubation chambers are in a same horizontal plane, wherein the at least two incubation chambers are configured such that the cell-encapsulated droplets move out of one of the at least two incubation chambers and travels vertically from a higher substrate layer of the platform to a lower layer of the platform to enter into another incubation chamber of the at least two incubation chambers, wherein the platform is configured such that the cell-encapsulated droplets travel vertically from a lower layer of the platform to a higher layer of the platform.

2 . The droplet microfluidic platform of claim 1 , further comprising a chamber configured to provide for on-chip recovery of the cell-encapsulated droplets.

3 . The droplet microfluidic platform of claim 1 , wherein the detection mechanism is configured to detect an optical, dielectric, conductivity, or vibrational spectroscopy signal.

4 . The droplet microfluidic platform of claim 1 , wherein the substrate layers comprises about 9 to about 20 polydimethylsiloxane layers.

5 . A method of producing the droplet microfluidic platform of claim 1 , the method comprising:

casting about 9 to about 20 individual polydimethylsiloxane layers from master molds;

bonding the individual polydimethylsiloxane layers into a single structure utilizing corresponding integrated alignment methods imbedded into each layer, comprising the functional components between adjacent layers; and

wherein the platform is capable of continuous/semi-continuous on-chip operation through a sequence of the functional components in a first-in first-out manner.

6 . A method of producing the droplet microfluidic platform of claim 1 comprising:

injection molding the substrate layers of the platform as individual pieces;

bonding the individual pieces into a single structure comprising the functional components between adjacent layers; and

wherein the platform is capable of continuous/semi-continuous on-chip operation through a sequence of the functional components in a first-in first-out manner.

7 . A method of producing the droplet microfluidic platform of claim 1 comprising:

injection molding the sandwich design into a single component; and

wherein the platform is capable of continuous/semi-continuous on-chip operation through a sequence of the functional components in a first-in first-out manner.

8 . A method for identifying cell-produced molecules affecting a target cell utilizing the droplet microfluidic platform of claim 1 , comprising:

generating continuously a first group of cell-encapsulated droplets from a library of cells that are potential producers of the cell-produced molecules that are capable of affecting the target cell;

incubating the first group of the cell-encapsulated droplets to provide time for the molecules produced by the cells to accumulate;

generating a second group of cell-encapsulated droplets containing the target cells;

merging of the first and second groups of cell-encapsulated droplets to allow co-incubation of both cell types and to provide time for the produced molecules to influence the target cells;

analyzing the cell-encapsulated droplets using the detection mechanism;

sorting the cell-encapsulated droplets; and recovering the sorted cell-encapsulated droplets.

9 . The method of claim 8 wherein the recovering of the sorted cell-encapsulated droplets is on-chip, wherein the on-chip analysis of the cell-encapsulated droplets comprises of at least one selected from the group consisting of:

determining expression or function of a nucleic acid or protein;

analyzing the growth rate, death, necrosis or apoptosis of the target cells; and

evaluating metabolic activity or production of metabolic products.

10 . The method of claim 9 wherein the detection mechanism is configured for the detection of fluorescent, colorimetric, dielectric, conductivity, or vibrational spectroscopy signals.

11 . A droplet microfluidic platform, comprising:

a plurality of substrate layers, and

a plurality of functional components,

wherein the plurality of substrate layers is configured such that, when the plurality of substrate layers are stacked, one or more of the plurality of functional components is collectively formed within two or more of the plurality of substrate layers, the functional components comprising:

at least one droplet generator for continuous generation of cell-encapsulated droplets;

at least one merging mechanism configured to merge the cell-encapsulated droplets;

at least two incubation chambers for on-chip incubation of the cell-encapsulated droplets;

at least a first valve for trapping or releasing the cell-encapsulated droplets;

a detection mechanism; and

a second valve configured to direct the cell-encapsulated droplets from a first of the at least two incubation chambers to a second of the at least two incubation chambers;

at least one passage to connect the functional components;

wherein the platform is capable of continuous/semi-continuous on-chip operation in a first-in first-out manner, wherein the platform comprises a stacked design, wherein the at least two incubation chambers are in different horizontal planes, wherein at least one of the at least two incubation chambers is located in higher substrate layers and at least one of the at least two incubation chambers is located in lower substrate layers, wherein the platform is configured such that the cell-encapsulated droplets traverse the platform vertically from a lower layer of the platform to a higher layer of the platform.

12 . The droplet microfluidic platform of claim 11 , further comprising a chamber configured to provide for on-chip recovery of the cell-encapsulated droplets.

13 . The droplet microfluidic platform of claim 11 , wherein the detection mechanism is configured to detect an optical, dielectric, conductivity, or vibrational spectroscopy signal.

14 . The droplet microfluidic platform of claim 11 , wherein the substrate layers comprises about 9 to about 20 polydimethylsiloxane layers.

15 . A method of producing the droplet microfluidic platform of claim 11 , the method comprising:

casting about 9 to about 20 individual polydimethylsiloxane layers from master molds;

bonding the individual polydimethylsiloxane layers into a single structure utilizing corresponding integrated alignment methods imbedded into each layer, comprising the functional components between adjacent layers; and

wherein the platform is capable of continuous/semi-continuous on-chip operation through a sequence of the functional components in a first-in first-out manner.

16 . A method of producing the droplet microfluidic platform of claim 11 comprising:

injection molding the substrate layers of the platform as individual pieces;

bonding the individual pieces into a single structure comprising the functional components between adjacent layers; and

wherein the platform is capable of continuous/semi-continuous on-chip operation through a sequence of the functional components in a first-in first-out manner.

17 . A method of producing the droplet microfluidic platform of claim 11 comprising:

injection molding the stacked design into a single component; and

wherein the platform is capable of continuous/semi-continuous on-chip operation through a sequence of the functional components in a first-in first-out manner.

18 . A method for identifying cell-produced molecules affecting a target cell utilizing the droplet microfluidic platform of claim 11 , comprising:

generating continuously a first group of cell-encapsulated droplets from a library of cells that are potential producers of the cell-produced molecules that are capable of affecting a target cell;

incubating the first group of the cell-encapsulated droplets to provide time for the molecules produced by the cells to accumulate;

generating a second group of cell-encapsulated droplets containing the target cells;

merging of the first and second groups of cell-encapsulated droplets to allow co-incubation of both cell types and to provide time for the produced molecules to influence the target cells;

analyzing the cell-encapsulated droplets using the detection mechanism;

sorting the cell-encapsulated droplets; and recovering the sorted cell-encapsulated droplets.

19 . The method of claim 18 wherein the recovering of the sorted cell-encapsulated droplets is on-chip, wherein the on-chip analysis of the cell-encapsulated droplets comprises of at least one selected from the group consisting of:

determining expression or function of a nucleic acid or protein;

analyzing the growth rate, death, necrosis or apoptosis of the target cells; and

evaluating metabolic activity or production of metabolic products.

20 . The method of claim 18 wherein the detection mechanism is configured for the detection of fluorescent, colorimetric, dielectric, conductivity, or vibrational spectroscopy signals.