Devices for generating monodisperse droplets from a bulk liquid
The invention provides devices that generate monodisperse droplets from a bulk liquid. The devices include a shearing mechanism, a holder for a vessel containing a liquid, and an optical system that transmit light to, and detects light from, liquid in the vessel. The invention also provides methods of using such devices to produce monodisperse droplets.
1 . A device comprising:
a shearing mechanism for applying shearing energy to thereby generate an emulsion to a liquid contained in at least one vessel;
a holder coupled to the shearing mechanism and configured to secure the at least one vessel;
an optical system comprising:
a light source positioned to transmit light to the liquid contained in the at least one vessel, and
a photodetector positioned to sense the transmitted light from the liquid contained in the at least one vessel, wherein the holder and optical system are movable relative to each other to adjust the position of the at least one vessel in relation to the light source and the photodetector; and
a control system coupled to the shearing mechanism and the optical system,
wherein the control system directs the shearing mechanism to alter the shearing energy applied to the liquid in response to the transmitted light and directs the shearing mechanism to stop applying shearing energy when the emulsion comprises substantially monodisperse droplets, and
wherein the control system directs the shearing mechanism to stop applying shearing energy in response to the photodetector sensing the transmitted light from the liquid contained in the at least one vessel within pre-defined maximum and minimum intensities of the sensed transmitted light.
2 . The device of claim 1 , wherein the shearing mechanism is selected from the group consisting of an agitator, piezoelectric motor, pipettor, shaker, sonicator, and vortexer.
3 . The device of claim 2 , wherein the shearing mechanism is a vortexer.
4 . The device of claim 1 , wherein the holder comprises a clamp.
5 . The device of claim 1 , wherein the light source is selected from the group consisting of a laser and a light emitting diode (LED).
6 . The device of claim 1 , wherein the photodetector is selected from the group consisting of a camera, charge-coupled device (CCD), complementary metal-oxide-semiconductor (CMOS) sensor, diode array, gaseous ionization detector, photodiode, photomultiplier tube, photoresistor, phototransistor, phototube, photovoltaic cell, pinned photodiode, quantum dot photoconductor, and quantum dot photodiode.
7 . The device of claim 1 , further comprising a user interface coupled to the optical system and the shearing mechanism, the user interface comprising:
at least one input sensor that receives input from a user; and
a display that displays to the user a readout from the optical system.
8 . The device of claim 1 , further comprising an adaptor configured to secure the at least one vessel to the holder.
9 . The device of claim 1 , further comprising a temperature regulator that regulates temperature of the liquid.
10 . The device of claim 1 , further comprising the at least one vessel.
11 . The device of claim 10 , wherein the device comprises a plurality of vessels.
12 . The device of claim 1 , wherein:
the at least one vessel comprises a plurality of wells that contain the liquid; and
the optical system comprises:
a plurality of light sources, each light source positioned to transmit light to a liquid contained in one of the plurality of wells, and
a plurality of photodetectors, each photodetector positioned to sense the transmitted light from the liquid contained in one of the plurality of wells.
13 . The device of claim 1 , wherein the holder is movable in at least one dimension to adjust the position of the at least one vessel in relation to the light source and the photodetector; the light source and the photodetector are movable in at least one dimension to adjust the position of the at least one vessel in relation to the light source and the photodetector; or both.
14 . A method for generating an emulsion comprising substantially monodisperse droplets, the method comprising:
contacting at least one vessel containing a liquid with a device comprising:
a shearing mechanism,
a holder configured to secure the at least one vessel and coupled to the shearing mechanism, and
an optical system comprising a light source and a photodetector, wherein the holder and optical system are movable relative to each other to adjust the position of the at least one vessel in relation to the light source and the photodetector;
applying shearing energy from the shearing mechanism to the liquid, thereby generating an emulsion comprising substantially monodisperse droplets;
adjusting the position of the holder relative to the optical system;
transmitting light from the light source to the liquid in the at least one vessel;
sensing, with the photodetector, the transmitted light from the liquid in the at least one vessel; and
directing the shearing mechanism to alter the shearing energy applied to the liquid in response to the photodetector sensing the transmitted light from the liquid contained in the at least one vessel within pre-defined maximum and minimum intensities of the sensed transmitted light.
15 . The method of claim 14 , wherein the directing step comprises directing the shearing mechanism to stop applying shearing energy to the liquid when the liquid comprises an emulsion comprising substantially monodisperse droplets.
16 . The method of claim 14 , further comprising:
comparing the transmitted light from the liquid in the at least one vessel to a reference.
17 . The method of claim 14 , wherein the holder is movable in at least one dimension to adjust the position of the at least one vessel in relation to the light source and the photodetector; the light source and the photodetector are movable in at least one dimension to adjust the position of the at least one vessel in relation to the light source and the photodetector; or both.