The present invention generally relates to systems and techniques for manipulating fluids and/or making droplets. In certain aspects, the present invention generally relates to droplet production. The droplets may be formed from fluids from different sources. In one set of embodiments, the present invention is directed to a microfluidic device comprising a plurality of droplet-making units, and/or other fluidic units, which may be substantially identical in some cases. Substantially each of the fluidic units may be in fluidic communication with a different source of a first fluid and a common source of a second fluid, in certain embodiments. In one aspect, substantially the same pressure may be applied to substantially all of the different sources of fluid, which may be used to cause fluid to move from the different sources into the microfluidic device. In some cases, the fluids may interact within the fluidic units, e.g., by reacting, or for the production of droplets within the microfluidic device. In some cases, the droplets may be used, for example, to form a library of droplets.

Described herein are systems relating to a continuous-flow instrument that includes all necessary components for digital droplet quantification without the need to introduce key reagents or collect and transfer droplets between stages of instrument operation. Digital quantification can proceed without any additional fluid or consumable handling and without exposing fluids to risk of external contamination.

A system and method for sample droplet processing, the system including a substrate, an electrode array network coupled to the substrate and configured to provide a pattern of controlled electric fields for manipulation of the set of sample droplets; a first layer in communication with the electrode array network, the first layer separating the electrode array network from fluid of the set of sample droplets; and a second layer opposing the first layer and displaced from the first layer to define a region wherein droplets of the set of sample droplets can reside. In some variations, the system can additionally include an electronics subsystem coupled to at least one of the substrate and the electrode array network, and a control module in communication with the electronics subsystem, wherein the control module generates and manipulates the pattern of controlled electric fields.

A first fluid is dispersed in a second fluid to form an emulsion of micro-droplets having an average droplet size and having a droplet size distribution around said average droplet size and below a maximum droplet size. Said micro-droplets will lose their solvent to transform to micro-spheres exhibiting a particle size distribution around an average particle size and substantially below a maximum allowable particle size. Said micro-spheres are subjected to a micro-filter having a relatively narrow pore size distribution around an average pore size, which average pore size is between said average particle size and said maximum particle size. A filtrate of said micro-filter comprises a majority of said micro-spheres that is substantially void of micro-spheres having a particle size exceeding the maximum allowable particle size.

A system and method for sample droplet processing, the system including a substrate, an electrode array network coupled to the substrate and configured to provide a pattern of controlled electric fields for manipulation of the set of sample droplets; a first layer in communication with the electrode array network, the first layer separating the electrode array network from fluid of the set of sample droplets; and a second layer opposing the first layer and displaced from the first layer to define a region wherein droplets of the set of sample droplets can reside. In some variations, the system can additionally include an electronics subsystem coupled to at least one of the substrate and the electrode array network, and a control module in communication with the electronics subsystem, wherein the control module generates and manipulates the pattern of controlled electric fields.

The present invention provides microfluidic technology enabling rapid and economical manipulation of reactions on the femtoliter to microliter scale.

A bridge (30) comprises a first inlet port (31) at the end of a capillary, a narrower second inlet port (32) which is an end of a capillary, an outlet port (33) which is an end of a capillary, and a chamber (34) for silicone oil. The oil is density-matched with the reactor droplets such that a neutrally buoyant environment is created within the chamber (34). The oil within the chamber is continuously replenished by the oil separating the reactor droplets. This causes the droplets to assume a stable capillary-suspended spherical form upon entering the chamber (34). The spherical shape grows until large enough to span the gap between the ports, forming an axisym metric liquid bridge. The introduction of a second droplet from the second inlet port (32) causes the formation of an unstable funicular bridge that quickly ruptures from the, finer, second inlet port (32), and the droplets combine at the liquid bridge (30). In another embodiment, a droplet (55) segments into smaller droplets which bridge the gap between the inlet and outlet ports.

Various aspects of the present invention relate to the control and manipulation of fluidic species, for example, in microfluidic systems. In one aspect, the invention relates to systems and methods for making droplets of fluid surrounded by a liquid, using, for example, electric fields, mechanical alterations, the addition of an intervening fluid, etc. In some cases, the droplets may each have a substantially uniform number of entities therein. For example, 95% or more of the droplets may each contain the same number of entities of a particular species. In another aspect, the invention relates to systems and methods for dividing a fluidic droplet into two droplets, for example, through charge and/or dipole interactions with an electric field. The invention also relates to systems and methods for fusing droplets according to another aspect of the invention, for example, through charge and/or dipole interactions. In some cases, the fusion of the droplets may initiate or determine a reaction. In a related aspect of the invention, systems and methods for allowing fluid mixing within droplets to occur are also provided. In still another aspect, the invention relates to systems and methods for sorting droplets, e.g., by causing droplets to move to certain regions within a fluidic system. Examples include using electrical interactions (e.g., charges, dipoles, etc.) or mechanical systems (e.g., fluid displacement) to sort the droplets. In some cases, the fluidic droplets can be sorted at relatively high rates, e.g., at about 10 droplets per second or more. Another aspect of the invention provides the ability to determine droplets, or a component thereof, for example, using fluorescence and/or other optical techniques (e.g., microscopy), or electric sensing techniques such as dielectric sensing.

The present invention relates to extended release microparticles comprising a drug, and a preparation method therefor, and when the extended release microparticles comprising a drug are administered in order to replace conventional drugs that should be administered daily or monthly, the drug administration effect can be continuously maintained for one week to three months.

In addition, the drug administration effect is maintained for a long time and, simultaneously, microparticles are prepared so as to have the average diameter of a fixed micro-size, and thus an effective drug concentration can be constantly maintained by controlling the release of the drug from the microparticles, and a foreign body sensation and pain can be reduced during drug administration since microparticles having a uniform size are included during application as an injectable drug.

The invention describes a method for isolating one or more genetic elements encoding a gene product having a desired activity, comprising the steps of: (a) compartmentalising genetic elements into microcapsules; and (b) sorting the genetic elements which express the gene product having the desired activity; wherein at least one step is under microfluidic control. The invention enables the in vitro evolution of nucleic acids and proteins by repeated mutagenesis and iterative applications of the method of the invention.