Abstract: A method and system for generating a flow of droplets comprising providing a first droplet fluid, providing a second droplet fluid, providing a carrier fluid and forming a double emulsion of droplets each comprising a first droplet region comprising the first droplet fluid surrounded by a second droplet region comprising the second droplet fluid within the carrier fluid, by providing a flow of said first droplet fluid, a flow of said second droplet fluid, and a flow of said carrier fluid to a droplet generation sub-system of a microfluidic structure.

Abstract: A method and system for determining droplet frequency of a flow of microfluidic droplets within a microfluidic droplet channel, comprising illuminating the flow of microfluidic droplets, using a beam splitter to split light from the flow of microfluidic droplets into a first portion and a second portion, directing the first portion to a camera, directing the second portion through an aperture located in front of a photodetector to the photodetector, and processing a signal from the photodetector and determining a droplet frequency from fluctuations in the processed signal. The method may be used to determine droplet dimension. The method may also be used to adjust a pressure of a flow of droplet fluid in response to a determined droplet dimension to generate a flow of droplets.

Abstract: A method of label-free cell or particle sorting in a microfluidic device includes providing a stream of aqueous droplets in oil in a channel of the microfluidic device, wherein at least some of the droplets include cells or particles and illuminating the stream from a first direction. Then, one detects scattered light from cells or particles within said aqueous droplets in a second direction. Next, one determines a number of the cells or particles in each droplet from the scattered light and sorts the aqueous droplets into differentiated streams. Notably, the refractive index of said oil is modified to closely match a refractive index of the aqueous droplets to reduce light scattered from boundaries of the droplets. A volume of the droplets can also controlled.

Abstract: The present invention provides an emulsion for sorting droplets in a microfluidic device, the emulsion comprising: a discontinuous aqueous phase; and a continuous oil phase; wherein said aqueous phase comprises at least one analyte, said oil phase comprises a fluorous oil and a refractive index modifying compound comprising at least one aromatic ring, and the refractive index of said aqueous phase and the refractive index of said oil phase are substantially matched.

Abstract: We describe a method of label-free cell and/or particle sorting in a microfluidic device, the method comprising; providing a stream of aqueous droplets in oil in a channel of said microfluidic device, wherein at least some of said droplets include cells and/or particles illuminating said stream from a first direction; detecting, for example, scattered light from cells and/or particles within said aqueous droplets in a second direction; determining, for example, a number of said cells and/or particles in each droplet from the scattered light; and sorting said aqueous droplets into one of a plurality of differentiated streams responsive to said determined number. The method further comprises modifying a refractive index of said oil to more closely match a refractive index of said aqueous droplets to reduce light scattered from boundaries of said droplets. Optionally a volume of the droplets is also controlled. In embodiments the oil is fluorous oil.

Abstract: The present invention provides an emulsion for sorting droplets in a microfluidic device, the emulsion comprising: a discontinuous aqueous phase; and a continuous oil phase; wherein said aqueous phase comprises at least one analyte, said oil phase comprises a fluorous oil and a refractive index modifying compound comprising at least one aromatic ring, and the refractive index of said aqueous phase and the refractive index of said oil phase are substantially matched.

Abstract: A flow cell for a microfluidic device can include a chamber, first microfluidic entry and exit channels, second microfluidic entry and exit channels, a first electrode, and a second electrode. A microfluidic device can include a microfluidic channel, a laser to excite fluorescent material, and a detector to detect fluorescence emission. Methods of merging a droplet from an emulsion in to a second stream of fluid and of detecting a content of a droplet in a stream are further disclosed.

Abstract: A method for monitoring torque in a gear train includes coincidently determining angles of rotation of first and second rotationally coupled members of the gear train. Each of the members employs a respective rotational position sensor. Each of said angles of rotation are determined based upon times corresponding to a last signal pulse, a next-to-last signal pulse, and a total quantity of signal pulses generated by the respective rotational position sensor during a current sampling interval. A twist angle corresponding to a difference between the angles of rotation of the first and second rotationally coupled members of the gear train is determined, and torque corresponding to the twist angle is calculated.

Abstract: This invention relates to microfluidic systems and more particularly to methods and apparatus for accessing the contents of micro droplets (114) in an emulsion stream. A method of accessing the contents of a droplet (114) of an emulsion in a microfluidic system, the method comprising: flowing the emulsion alongside a continuous, non-emulsive stream of second fluid (118) to provide an interface (120) between said emulsion and said stream of second fluid (118); and in embodiments applying one or both of an electric (112a, 112b) and magnetic field across said interface (120) to alter a trajectory of a said droplet (114) of said emulsion to cause said droplet to coalesce with said stream of second fluid (118); and accessing said contents of said droplet (114) in said second stream (118).

Abstract: A flow cell for a microfluidic device can include a chamber, first microfluidic entry and exit channels, second microfluidic entry and exit channels, a first electrode, and a second electrode. A microfluidic device can include a microfluidic channel, a laser to excite fluorescent material, and a detector to detect fluorescence emission. Methods of merging a droplet from an emulsion in to a second stream of fluid and of detecting a content of a droplet in a stream are further disclosed.

Abstract: A method for monitoring torque in a gear train includes coincidentally determining angles of rotation of first and second rotationally coupled members of the gear train. Each of the members employs a respective rotational position sensor. Each of said angles of rotation are determined based upon times corresponding to a last signal pulse, a next-to-last signal pulse, and a total quantity of signal pulses generated by the respective rotational position sensor during a current sampling interval. A twist angle corresponding to a difference between the angles of rotation of the first and second rotationally coupled members of the gear train is determined, and torque corresponding to the twist angle is calculated.

Abstract: This invention relates to microfluidic systems and more particularly to methods and apparatus for accessing the contents of micro droplets (114) in an emulsion stream. A method of accessing the contents of a droplet (114) of an emulsion in a microfluidic system, the method comprising: flowing the emulsion alongside a continuous, non-emulsive stream of second fluid (118) to provide an interface (120) between said emulsion and said stream of second fluid (118); and in embodiments applying one or both of an electric (112a, 112b) and magnetic field across said interface (120) to alter a trajectory of a said droplet (114) of said emulsion to cause said droplet to coalesce with said stream of second fluid (118); and accessing said contents of said droplet (114) in said second stream (118).