Droplet-generating microfluidic chips and related methods

Inventors

Johnson, Ross

Assignees

Pattern Bioscience Inc

Abstract

A microfluidic chip that can have a body defining a microfluidic network including a test volume, one or more ports, and one or more channels in fluid communication between the port(s) and the test volume. Gas can be removed from the test volume before a sample liquid is introduced therein by reducing pressure at a first one of the port(s), optionally while the liquid is disposed in the port. Liquid in the first port can be introduced into the test volume by increasing pressure at the first port. The microfluidic network can define one or more droplet-generating regions in which at least one of the channel(s) defines a constriction and/or two or more of the channels connect at a junction. Liquid flowing from the first port can pass through at least one of the droplet-generating region(s) and to the test volume.

Core Innovation

The document describes a microfluidic chip that cooperates first and second pieces to define a microfluidic circuit having an inlet port and a droplet-generating region that delivers droplets to a test volume. The droplet-generating region includes a constriction section configured to receive liquid from the inlet port, and the constriction section transitions into an expansion region having a constant portion extending from the constriction section and having a substantially constant transverse dimension larger than the transverse dimension of the constriction section.

The expansion region further includes an expanding portion defining a ramp that extends from the constant portion. The ramp is defined by a surface inclined relative to the length of the constant portion or by at least three steps, and it has a slope of between 10 and 80 degrees. The expanding portion has an increasing transverse dimension along its length, increasing from the transverse dimension of the constant portion to a value larger than the transverse dimension of the constant portion.

The chip is further defined by mating surfaces across the first and second pieces, where the first piece defines a first surface of the constriction section and a first surface of the constant portion that is coplanar with the first surface of the constriction section, and the second piece defines a second surface of the constriction section opposite to the first surface and a second surface of the constant portion opposite to the first surface. The second surface of the constant portion is parallel to and offset from the second surface of the constriction section.

Claims Coverage

The document includes two independent claims. The coverage centers on a droplet-generating region geometry with a constriction section transitioning into an expansion region having a constant portion and an expanding ramp defined either by an inclined surface or at least three steps, with specified ramp slope and an increasing transverse dimension from the constant portion to a larger value.

The independent claims define a consistent droplet-generating region architecture with a constriction section followed by an expansion region having a constant portion and a ramp that increases transverse dimension, and they distinguish a chip structure claim from a loading method claim that forms aqueous droplets in the presence of a non-aqueous liquid and directs droplets to a test volume.

Stated Advantages

Documented Applications