Fluid triggerable valves

Patent metadata

Field	Value
Publication number	US-9429249-B2
Application number	US-201414465345-A
Country	US
Kind code	B2
Filing date	Aug 21, 2014
Priority date	Aug 8, 2013
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

The present invention relates to a fluid triggerable passive valve for controlling flow of one or more fluids comprising:
a volume comprising at least two capillary pressure barriers for respectively pinning a first and second fluid-fluid meniscus, the two capillary pressure barriers dividing the volume in at least three sub volumes, whereby two sub volumes being positioned upstream and one sub volume being positioned downstream with respect to the advancement direction of each respective fluid-fluid meniscus;

wherein the capillary pressure barriers are spaced apart such that upon pinning of a first fluid-fluid meniscus on a first capillary pressure barrier and arrival or pinning of a second fluid-fluid meniscus on or at a second capillary pressure barrier, the two menisci touch and thereby coalesce into one fluid-fluid meniscus.

First claim

The invention claimed is:

1. A fluid triggerable passive valve for controlling flow of one or more fluids comprising:
a volume comprising at least two capillary pressure barriers for respectively pinning a first and second fluid-fluid meniscus,
the two capillary pressure barriers dividing the volume in at least three sub volumes, whereby two sub volumes being positioned upstream and one sub volume being positioned downstream with respect to the advancement direction of each respective fluid-fluid meniscus;
wherein the capillary pressure barriers are spaced apart such that upon pinning of a first fluid-fluid meniscus on a first capillary pressure barrier and arrival or pinning of a second fluid-fluid meniscus on or at a second capillary pressure barrier, the two menisci touch and thereby coalesce into one fluid-fluid meniscus.

2. A valve according to claim 1 , where upon coalescence of the two fluid-fluid menisci, the pressure required for breaching the pinned state of the resulting fluid-fluid meniscus is lower than the pressure required for breaching the pinned state of one or more fluid-fluid meniscus before coalescence.

3. A valve according to claim 1 , wherein upon coalescence of the two fluid-fluid menisci the pinning of the resulting fluid-fluid meniscus is relieved and the meniscus is permitted to advances in downstream direction.

4. A valve according to claim 1 , whereby at least one of each sub-volumes comprises or is a microfluidic channel.

5. A valve according to claim 1 , where at least one capillary pressure barrier is stabilized by
(a) subtending at both ends an angle with a wall of the volume that on the downstream side of the capillary pressure barrier is greater than 90°,
and/or
(b) wherein the capillary pressure is stabilized by providing a stretching barrier at a distance less than the maximum stretching distance of the fluid-fluid meniscus upon alignment along the capillary pressure barrier in the absence of the stretching barrier, the stretching barrier being shaped such that at least one directional component is orthogonal to the capillary pressure barrier and/or
(c) the capillary pressure barrier is stabilized by subtending at one end an angle with a wall of the volume that on the downstream side of the capillary pressure barrier is greater than 90°, and at the other end is stabilized by providing a stretching barrier at a distance less than the maximum stretching distance of the fluid-fluid meniscus upon alignment along the capillary pressure barrier in the absence of the stretching barrier, the stretching barrier being shaped such that at least one directional component is orthogonal to the capillary pressure barrier.

6. A valve according to claim 5 , wherein the stretching barrier is defined or includes one or more of:
iv) a recess or groove defined in the material of a wall of the volume;
v) a protuberance from a wall of the volume into the volume;
vi) a bend or recess opening into a further channel or reservoir;
vii) a line defined in or on the material of a wall of the volume that is of lower wettability than the material of the said wall adjacent the line.

7. A valve according claim 5 , wherein the two capillary pressure barriers are stabilized by at least one common stretching barrier.

8. A valve according to claim 7 , whereby coalescence of the two menisci results in breaching the at least one common stretching barrier.

9. A valve according to claim 1 , wherein the capillary pressure barrier is defined by or includes one or more of:
i) a recess or groove defined in the material of a wall of the volume;
ii) a protuberance from a wall of the volume into the volume; and/or
iii) a line defined in or on the material of a wall of the volume that is of lower wettability than the material of the said wall adjacent the line.

10. A valve according to claim 1 , wherein the distance that the two capillary pressure barriers are spaced apart is less than twice the maximum stretching distance of each fluid-fluid meniscus that is pinned on one said capillary pressure barrier in the absence of the second fluid-fluid meniscus.

11. A valve according to claim 10 , wherein the maximum stretching distance, d s , is defined by formula I:

d
s

=

g
⁡

(

cos
⁢

⁢

θ
2

-

sin
⁢

⁢

θ
1

cos
⁢

⁢

θ
1

-

sin
⁢

⁢

θ
2

)

,

(
I
)

wherein g represents the distance between the first substrate on which the first capillary pressure barrier is provided and the second substrate facing the substrate on which the first capillary pressure barrier is provided;
wherein θ 1 represents the contact angle of the fluid with the material of the substrate facing the first capillary pressure barrier; and wherein θ 2 represents the contact angle of the fluid with the capillary pressure barrier material.

12. A valve according to claim 1 , wherein the volume comprises two capillary pressure barriers for holding two fluid-fluid menisci and an intermediate volume defined by the two capillary pressure barriers and the menisci once pinned, wherein the two capillary pressure barriers converge at a minimal distance at le

Assignees

• Univ Leiden

Inventors

• Vulto Paul
• Trietsch Sebastiaan Johannes
• Yildirim Ender

Classifications

• B01L2400/0688

  surface tension valves, capillary stop, capillary break · CPC title

• F16K2099/0084

  Chemistry or biology, e.g. "lab-on-a-chip" technology · CPC title

• B01L3/502738 Primary

  characterised by integrated valves (throttle valves in microfluidic sample containers B01L3/502746) · CPC title

• B01L3/502746

  characterised by the means for controlling flow resistance, e.g. flow controllers, baffles or throttle valves · CPC title

• B01L2400/0406

  capillary forces · CPC title