David F Weitz

US Patent:

20040010060, Jan 15, 2004

Filed:

Mar 19, 2003

Appl. No.:

10/392123

Inventors:

Mathieu Joanicot - Chatenay-Malabry, FR
Ani Nikova - San Diego CA, US
Maria Talingting - Burlington NJ, US
David Weitz - Bolton MA, US

International Classification:

C08F002/00

US Classification:

523/201000

Abstract:

The invention relates to new vesicles structures, and their use for delivering actives. The vesicles according to the invention are obtained from di-block copolymers. The vesicles comprise an external shell of a di-block copolymer comprising a hydrophilic block and a hydrophobic block, and at least one internal shell of the same or another di-block copolymer comprising a hydrophilic block and a hydrophobic block, the hydrophobic block of the external shell facing the hydrophobic block of the internal shell(s), and further comprise a hydrophobic compound between the shells.

US Patent:

20070195127, Aug 23, 2007

Filed:

Jan 24, 2007

Appl. No.:

11/698298

Inventors:

Keunho Ahn - San Diego CA, US
Henry Chong - Cambridge MA, US
Jeremy Agresti - Cambridge MA, US
David Weitz - Bolton MA, US
Darren Link - Guilford CT, US

Assignee:

President and Fellows of Harvard College - Cambridge MA

International Classification:

B41J 2/06

US Classification:

347055000

Abstract:

The present invention generally relates to systems and methods for the control of fluidic species and, in particular, to the coalescence of fluidic droplets. In certain instances, the systems and methods are microfluidic. In one aspect, the invention relates to systems and methods for causing two or more fluidic droplets within a channel to coalescence. The fluidic droplets may be of unequal size in certain cases. In some embodiments, a first fluidic droplet may be caused to move at a first velocity, and a second fluidic droplet may be caused to move at a second velocity different from the first velocity, for instance, substantially greater than the first velocity. The droplets may then coalesce, for example, upon application of an electric field. In the absence of an electric field, in some cases, the droplets may be unable to coalesce. In some cases, two series of fluidic droplets may coalesce, one or both series being substantially uniform. For instance, one series of droplets may have a distribution of diameters such that no more than about 5% of the droplets have a diameter greater than about 10% of the average diameter. In certain cases, one or more series of droplets may each consist essentially of a substantially uniform number of entities of a species therein (i.e., molecules, cells, particles, etc.). The fluidic droplets may be coalesced to start a reaction, and/or to stop a reaction, in some cases. For instance, a reaction may be initiated when a species in a first droplet contacts a species in a second droplet after the droplets coalesce, or a first droplet may contain an ongoing reaction and a second droplet may contain a species that inhibits the reaction. Other embodiments of the invention are directed to kits or methods for promoting the coalescence of fluidic droplets.

US Patent:

20120167410, Jul 5, 2012

Filed:

Dec 20, 2011

Appl. No.:

13/330793

Inventors:

Adam R. Abate - San Francisco CA, US
Julian W.P. Thiele - Schwarzenbek, DE
David A. Weitz - Bolton MA, US
Christian Holtze - Frankfurt, DE
Maike Windbergs - Saarbruecken, DE

Assignee:

BASF SE - Ludwigshafen
President and Fellows of Harvard College - Cambridge MA

International Classification:

F26B 21/00
F26B 3/02

US Classification:

34443, 34523, 34282

Abstract:

The present invention generally relates to microfluidics, and to spray drying and other drying techniques. In some aspects, an article containing one or more channels or microfluidic channels is used to mix one or more fluids prior to spray drying. The mixing may occur immediately before the fluids are expelled through a nozzle or other opening into a drying region of the spray dryer. In one set of embodiments, for example, a first fluid is exposed to a second fluid, then the fluids are exposed to air or other gases before being expelled through a nozzle. In certain instances, the first fluid may contain a dissolved species that may precipitate upon exposure to the second fluid; such precipitation may occur immediately before expulsion through a nozzle or other opening, thereby resulting in controlled precipitation as part of the spray drying process.

US Patent:

20140026968, Jan 30, 2014

Filed:

Feb 6, 2012

Appl. No.:

13/979984

Inventors:

Adam R. Abate - San Francisco CA, US
David A. Weitz - Bolton MA, US

International Classification:

B01L 3/00

US Classification:

137 1, 137561 A

Abstract:

The present invention generally relates to fluidics and microfluidics and, in particular, to creating droplets in a fluidic system. In some aspects, the present invention is generally directed to systems and methods for splitting a parent droplet into two or more droplets, e.g., by urging the parent droplet towards an obstacle to split the parent droplet. In some cases, the parent droplet is split into at least first and second droplets which each are directed to separate channels. In some cases, the channels may be constructed and arranged such that the droplet velocities of the first and second droplets are substantially the same as the velocity of the parent droplet. In some cases, such droplets may be repeatedly split, e.g., a parent droplet is divided into 2 daughter droplets, then each droplet split again, etc., for example, such that one parent droplet may eventually be split into 2, 2, 2, 2, 2, etc. daughter droplets. In some cases, the daughter droplets may be substantially monodisperse.

US Patent:

20150360186, Dec 17, 2015

Filed:

May 12, 2015

Appl. No.:

14/710223

Inventors:

- Cambridge MA, US
Adam R. Abate - San Francisco CA, US
David A. Weitz - Bolton MA, US

International Classification:

B01F 13/00
B01L 3/00
B01F 3/08

Abstract:

Parallel uses of microfluidic methods and devices for focusing and/or forming discontinuous sections of similar or dissimilar size in a fluid are described. In some aspects, the present invention relates generally to flow-focusing-type technology, and also to microfluidics, and more particularly parallel use of microfluidic systems arranged to control a dispersed phase within a dispersant, and the size, and size distribution, of a dispersed phase in a multi-phase fluid system, and systems for delivery of fluid components to multiple such devices.

US Patent:

20140338753, Nov 20, 2014

Filed:

Sep 27, 2012

Appl. No.:

14/348113

Inventors:

- Cambridge MA, US
Adam R. Abate - San Francisco CA, US
David A. Weitz - Bolton MA, US

International Classification:

B01L 3/00

US Classification:

137 13, 137814, 422502

Abstract:

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.