BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] The invention relates to microfluidics technology, and more particularly to a microfluidic
pump for control of fluid flow through microchannels.
BACKGROUND INFORMATION
[0002] Microfluidics systems are of significant value for acquiring and analyzing chemical
and biological information using very small volumes of liquid. Use of microfluidic
systems can increase the response time of reactions, minimize sample volume, and lower
reagent and consumables consumption. When volatile or hazardous materials are used
or generated, performing reactions in microfluidic volumes also enhances safety and
reduces disposal quantities.
[0003] Microfluidic devices have becoming increasingly important in a wide variety of fields
from medical diagnostics and analytical chemistry to genomic and proteomic analysis.
They may also be useful in therapeutic contexts, such as low flow rate drug delivery.
[0004] The microcomponents required for these ends are often complex and costly to produce.
For example, a micropump may be used to mix reagents and transport fluids between
a disposable analysis platform component of the system and an analysis instrument
(
e.g., an analyte reader with display functions). Yet controlling the direction and rate
of fluid flow within the confines of a microfluidic device, or achieving complex fluid
flow patterns inside microfluidic channels is difficult.
[0005] Document
US 2006/0166357 A1 discloses a microfluidic device having a channel in a substrate of elastomeric material,
on top of which is an elastomeric cover with a tactile device having an actuator extendable
downwardly by application of an actuating signal through wires.
SUMMARY OF THE INVENTION
[0006] A microfluidic pump has been developed in order to provide low cost, high accuracy
means for onboard sample handling in disposable assay devices. Devices utilizing the
microfluidic pump, as well as methods for manufacture and performing a microfluidic
process are also provided.
[0007] In a first aspect, the invention provides a microfluidic pump, comprising: a microchannel
defined by (a) a groove in a first surface of a first substrate, and (b) a second
surface of a second substrate; and an actuator configured to compress a portion of
the second substrate into the groove of the first substrate without substantially
deforming the groove, characterized in that the actuator is configured to translate
along an axis of the groove.
[0008] In an embodiment, the groove has a height and the height is at least about 10 microns,
at least about 20 microns, at least about 30 microns, or at least about 50 microns
and/or wherein the groove has a height and the height is about 1000 microns or less,
about 500 microns or less, about 250 microns or less, about 125 microns or less, about
100 microns or less, about 75 microns or less.
[0009] In an embodiment, the first and second substrates are substantially planar.
[0010] In an embodiment, the channel has an inlet and an outlet and a distance between the
inlet and the outlet is at least about 1 mm, at least about 2.5 mm, at least about
5 mm, at least about 10 mm, at least about 25 mm and/or wherein the channel has an
inlet and an outlet and a distance between the inlet and the outlet is about 250 mm
or less, 100 mm or less, about 75 mm or less, about 50 mm or less, about 25 mm or
less.
[0011] In an embodiment, the pump is disposed in fluidic communication with a microfluidic
device. In an embodiment, the pump comprises at least one microchannel configured
to receive a liquid sample suspected of containing at least one target and the microchannel
comprises at least one reagent for use in determining the presence of the at least
one target. In an embodiment, the pump is configured to produce a gas pressure acting
upon a distal gas-liquid interface of the liquid sample when the distal gas-liquid
interface of the liquid sample is disposed within the microchannel of the microfluidic
device. A proximal gas-liquid interface of the liquid sample may be exposed to an
ambient atmosphere. The gas pressure acting upon the distal gas-liquid interface of
the liquid sample may be less than an ambient gas pressure. The first and second substrates
may be disposed within the microfluidic device. In an embodiment, the microchannel
of the microfluidic device comprises the liquid sample disposed therein, optionally
wherein the liquid sample comprises urine or at least one liquid component of blood.
In an embodiment, the actuator is configured to provide a rate of flow of the liquid
sample within the microchannel of the microfluidic device of at least about 1 nl/s,
at least about 5 nl/s, at least about 10 nl/s, at least about 25 nl/s, at least about
50 nl/s, at least about 100 nl/s, at least about 250 nl/s, at least about 500 nl/s
at least about 1000 nl/s and/or wherein the actuator is configured to provide a rate
of flow of the liquid sample within the microchannel of the microfluidic device of
about 10,000 nl/s or less, about 5,000 nl/s or less, about 2,500 nl/s or less, at
least about 1000 nl/s or less. In an embodiment, a total volume of liquid sample within
the microchannel is about 100 microliters or less, about 50 microliters or less, about
25 microliters or less, about 20 microliters or less.
[0012] In an embodiment, the channel has an uncompressed area and, when compressed by the
actuator, the compressed portion of the second substrate occludes at least about 50%,
at least about 75%, at least about 90%, at least about 95%, at least about 97.5%,
at least about 99%, or essentially all of the uncompressed area of the channel.
[0013] In an embodiment, in the uncompressed state, the groove has a width and the width
is at least about 50 microns, at least about 100 microns, at least about 200 microns,
at least about 500 microns, optionally wherein, in the compressed state, the width
of the groove is at least about 75%, at least about 90%, at least about 95%, at least
about 97.5%, at least about 99%, or essentially the same as in the uncompressed state.
[0014] In an embodiment, in the compressed state, the groove has a width and the width is
about 2000 microns or less, about 1500 microns or less, about 1000 microns or less,
about 750 microns or less about 600 microns or less, optionally wherein, in the compressed
state, the height of the groove is at least about 75%, at least about 90%, at least
about 95%, at least about 97.5%, at least about 99%, or essentially the same as in
the uncompressed state.
[0015] In an embodiment, in the uncompressed state, the second substrate has a first thickness
overlying the groove and a second thickness spaced apart laterally a first distance
from the groove and wherein the second thickness is at least about 110%, at least
about 125%, at least about 150%, at least about 175%, or at least about 200% greater
than the first thickness, optionally wherein the first distance is at about 50% greater
than a width of the groove, about 75% greater than a width of the groove, about 100%
greater than a width of the groove, about 200% greater than a width of the groove.
[0016] Also disclosed is a microfluidic pump module. The microfluidic pump module may include
a first plate element and a second plate element, the first plate element being elastomeric
and the second plate element being non-elastomeric. The second plate element includes
a microchannel formed on a surface of the second plate element, and the first and
second plate elements are coupled to form a fluid tight seal along the boundary of
the microchannel defining a fluid flow path.
[0017] Also disclosed is a microfluidic device utilizing the microfluidic pump module described
herein. The microfluidic device includes (a) a rigid substrate having a microchannel
formed on a surface thereof; and (b) a flexible layer coupled to and overlying the
rigid substrate thereby enclosing the microchannel, wherein the flexible layer comprises
a raised element disposed over a portion or all of the microchannel. The device further
includes a fluid tight seal formed between the rigid substrate and the flexible layers
along a periphery of the microchannel forming an enclosed capillary.
[0018] Also disclosed is a microfluidic device utilizing the microfluidic pump module described
herein. The microfluidic device includes (a) a rigid substrate having a microchannel
formed on a surface thereof; and (b) a flexible layer coupled to and overlying the
rigid substrate thereby enclosing the microchannel, wherein the flexible layer has
a flat surface disposed over a portion or all of the microchannel. The device further
includes a fluid tight seal formed between the rigid substrate and the flexible layers
along a periphery of the microchannel forming an enclosed capillary.
[0019] Also disclosed is a microfluidic device utilizing the microfluidic pump module described
herein, wherein the pump module comprises at least two independent microchannels arranged
in a substantially parallel manner. One or more actuators are provided which act upon
the two or more microchannels simultaneously, thereby providing means to pump two
fluids separate from one another. The microchannels may have identical cross sectional
areas, such that the volume of fluid transported per unit distance of the microchannel
is substantially the same. The at least two microchannels may have different cross
sectional areas, in which instance the volume of fluid transported per unit distance
of the microchannel is different.
[0020] Also disclosed is a microfluidic device utilizing the microfluidic pump module described
herein, wherein the pump module comprises at least two independent microchannels arranged
concentrically about a point upon which at least one actuator rotates. Where the at
least two microchannels have identical cross sectional area, per revolution of the
at least one actuator, a greater volume of fluid will be transported in the outermost
channel according to the equation Q = rωA, where Q is the volume flow rate, r is the
radius of the microchannel, ω is the angular velocity and A is the cross sectional
area of the microchannel. Thus if the outermost channel has a radius r2, which is
three times the radius of the inner most channel r1, then three times the volume of
fluid will be transported in the outermost channel compared with the innermost channel
per revolution of the actuator. The skilled person will thus readily recognize that
by altering the relative ratio of cross sectional area of the respective concentric
microchannels, different volumes of fluid may be transported per revolution in each
respective channel.
[0021] Also disclosed is a method for performing a microfluidic process. The method includes
(a) applying a voltage to a microfluidic pump module as described herein. The applied
voltage activates a motor which advances an actuator element, such as one or more
rollers, which is rotatably engaged with the second substrate, causing deformation
of the second substrate into the microchannel formed on the surface of the first substrate.
Deformation of the elastomeric second substrate into the microchannel forces fluid
within the microchannel along the microchannel resulting in a fluid flow. The first
substrate is formed from a material having a Shore D hardness of between about 75
and about 90. Such materials include, but are not limited to, polystyrene, polypropylene,
polymethylmethacrylate, polycarbonate and the like. The microchannel or groove formed
in the surface of the first substrate is dimensionally stable, by which is meant that
when the second substrate is deformed into the groove in the first substrate, the
width of the groove is at least about 75%, at least about 90%, at least about 95%,
at least about 97.5%, at least about 99%, or essentially the same as in the uncompressed
state and height the groove is at least about 75%, at least about 90%, at least about
95%, at least about 97.5%, at least about 99%, or essentially the same as in the uncompressed
state. The dimensions of the groove are thus considered to be essentially unchanged
as a consequence of the deformation of the second substrate into the first substrate,
The second substrate is formed from a material having a Shore A hardness of between
about 15 and 90. Such materials include, but are not thermoplastic elastomer (TPE),
polydimethylsiloxane (PDMS), silicone rubber, fluoroelastomer and the like. Such materials
are considered to be dimensionally unstable, by which is meant that when a compressive
force or a stretching force is applied to such polymeric materials the material deforms,
either through elongation in one or more directions, or the material compresses in
one or more dimensions.
[0022] Also disclosed is a method of manufacturing a microfluidic device. The method includes
coupling a rigid substrate having a microchannel formed on a surface thereof, to a
flexible layer overlying the rigid substrate and enclosing the microchannel. A fluid
tight seal is formed between the rigid substrate and the flexible layers along a periphery
of the microchannel forming an enclosed capillary. The rigid substrate and the flexible
layer are coupled via a laser welding process. The process includes:
- (a) exposing one of the rigid substrate or the flexible layer to ultra violet laser
energy around the periphery of the microchannel so as to carbonize the surface of
the rigid substrate or the flexible layer;
- (b) applying a compressive force between the rigid substrate and the flexible layer;
and
- (c) exposing the compressed rigid substrate and the flexible layer to infra red laser
energy to cause localized heating and melting in the proximity of the carbonized surface
of (a) so as to seal the rigid substrate and the flexible layer, thereby forming a
fluid tight seal along the boundary of the microchannel.
[0023] Also disclosed is a method of manufacturing a microfluidic device. The method includes
coupling a rigid substrate having a microchannel formed on a surface thereof, to a
flexible layer overlying the rigid substrate and enclosing the microchannel. A fluid
tight seal is formed between the rigid substrate and the flexible layers along a periphery
of the microchannel forming an enclosed capillary. The rigid substrate and the flexible
layer are coupled via a process of over-molding. The process includes:
- (a) injecting a first polymer composition into an injection mold cavity to form the
rigid substrate;
- (b) injecting a second polymer composition into an injection mold cavity to form the
flexible layer; and
- (c) causing the molten second polymeric material to fuse with the first polymeric
material introduced in (a) so as to seal the rigid substrate and the flexible layer,
thereby forming a fluid tight seal along the boundary of the microchannel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
Figure 1 is a series of schematics illustrating movement of various components during
operation of a microfluidic device in embodiments of the invention.
Figure 1A is a cross-sectional view of a portion of a microfluidic device in embodiments
of the invention.
Figure 1B is a cross-sectional view of a portion of a microfluidic device in embodiments
of the invention.
Figure 2 is a cross-sectional view of a portion of a microfluidic device in embodiments
of the invention.
Figure 3 is a perspective view of a portion of a microfluidic device in an embodiment
of the invention.
Figure 4 is a top view of a portion of a microfluidic device in an embodiment of the
invention.
Figure 5 is a perspective view of a microfluidic device in an embodiment of the invention.
Figure 6 is a series of schematics illustrating a microfluidic device in embodiments
of the invention.
Figure 6A is a top view of a microfluidic device in an embodiment of the invention.
Figure 6B is a top view of a microfluidic device in an embodiment of the invention.
Figure 6C is a top view of a microfluidic device in an embodiment of the invention.
Figure 7 is a graphical representation depicting data generated with a microfluidic
device in an embodiment of the invention.
Figure 8 is a graphical representation depicting data generated with a microfluidic
device in an embodiment of the invention.
Figure 9 is a graphical representation depicting data generated with a microfluidic
device in an embodiment of the invention.
Figure 10 is a top view of a portion of a microfluidic device in an embodiment of
the invention.
Figure 11 is a cross-sectional schematic of a drive for use in one embodiment of the
invention.
Figure 12 is a cross-sectional schematic of a drive for use in one embodiment of the
invention.
Figure 13 is a top view schematic of a microfluidic device in an embodiment of the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] A microfluidic pump and device containing the pump have been developed in order to
provide, in embodiments, low cost, high accuracy and low flow rate means for onboard
sample handling for disposable assay devices. Advantageously, the rate of fluid flow
within the pump is essentially constant even at very low flow rates.
[0026] The pump comprises a first substrate and a second substrate secured with respect
to one another to provide a structure having one or more microchannels which are sealed
along the boundaries of the microchannels thereby defining fluid flow paths.
[0027] With reference to Figures 1A and 1B, one or more microchannel structures (40),
e.g., grooves, are formed in a major surface of a first substrate (20) formed,
e.g., of a non-elastomeric or rigid material. A deformable second substrate (10) formed,
e.g., of an elastomer, is secured with respect to first substrate 20 to create enclosed
microchannels (40) having a fluid tight seal along their boundaries. When a force,
for example via a deformation element such as roller (50), is applied to the elastomer
material (10), at least of portion of the second substrate is compressed into the
microchannel (40) of the non-elastomeric (20) component thereby occluding at least
a portion of the microchannel (40) at the site of compression.
[0028] In the compressed state, the second substrate typically occludes a sufficient portion
of the microchannel (40) to displace a substantial portion of fluid from microchannel
(40) at the site of compression. For example, the second substrate may occlude a sufficient
portion of the microchannel (40) to separate fluid disposed within microchannel (40)
on one side of the site of compression from fluid disposed within microchannel (40)
on the other side of the site of compression. In embodiments, the second substrate
occludes, in the compressed state, at least about 50%, at least about 75%, at least
about 90%, at least about 95%, at least about 97.5%, at least about 99%, or essentially
all of the uncompressed cross-sectional area of the groove at the site of compression.
[0029] The compression may create a fluid-tight seal between the first and second substrates
within the groove at the site of compression. When a fluid-tight seal is formed, fluid,
e.g., a liquid, is prevented from passing along the groove from one side of the site of
compression to the other side of the site of compression.
[0030] The fluid-tight seal may be transient,
e.
g., the second substrate may fully or partially relax upon removal of the compression
thereby fully or partially reopening the groove.
[0031] The groove has a first cross-sectional area in an uncompressed state and a second
cross-sectional area in the compressed state. In embodiments, the portion of the elastomer
is compressed into the groove without substantially deforming the groove. For example,
a ratio of the cross-sectional area at the site of compression in the compressed state
to the cross-sectional area at the same site in the uncompressed state may be at least
about 0.75, at least about 0.85, at least about 0.925, at least about 0.975, or about
1. In embodiments, the height of the groove,
e.g., the maximum height of the groove at the site of compression, in the compressed state
may be at least about 75%, at least about 85%, at least about 90%, at least about
95%, or about 100% of the height of the groove at the same site in the uncompressed
state. In embodiments, the width of the groove,
e.g., the maximum width of the groove at the site of compression, in the compressed state
may be at least about 75%, at least about 85%, at least about 90%, at least about
95%, or about 100% of the width of the groove at the same site in the uncompressed
state.
[0032] Translation of the site of compression along the length of the microchannel (40)
creates an effective pumping action resulting in flow of fluid within the microchannel
(40) in the direction of the advancing deformation element (50). In some embodiments
a raised element (30), such as a bump, is present on the elastomer (10), which may
be placed over the microchannel region (40), thereby increasing the thickness of elastomeric
material which may aid sealing of the elastomer into the channel when compressed against
the non-elastic component (20). For example, in the uncompressed state, the elastomer
may have a first thickness overlying the groove and a second thickness spaced apart
laterally a first distance from the center of the groove. In embodiments, the second
thickness is at least about 110%, at least about 125%, at least about 150%, at least
about 175%, or at least about 200% greater than the first thickness. The second thickness
may be at least about 500% or less, about 400% or less, about 300% or less, or at
about 250% or less greater than the first thickness.
[0033] The first distance may be at least about 1 mm, at least about 2.5 mm, at least about
5 mm, or at least about 1 cm. The first distance may be about 2.5 cm or less, about
2 cm or less, about 1.5 cm or less, or about 1.25 cm or less. In embodiments, the
first distance is at about 1.5 times greater, about 1.75 times greater, about 2 times
greater, or about 4 times greater than a width,
e.g., a maximum width, of the groove. The first distance may be about 25 times greater
or less, about 20 times greater or less, about 15 times greater or less, or about
10 times greater or less than a width,
e.g., a maximum width, of the groove.
[0034] Also disclosed is a microfluidic pump module (100) utilizing the microfluidic structure
described herein. Again with reference to Figures 1A and 1B, the microfluidic pump
module (100) includes a first elastomeric plate element (10) and a second rigid plate
element (20). The second plate element (20) includes a microchannel (40) formed on
a surface of the second plate element (20), and the first and second plate elements
are coupled to form a fluid tight seal along the boundary of the microchannel (40)
defining a fluid flow path.
[0035] Also disclosed is a microfluidic device (100) utilizing the microfluidic pump module
described herein. Again with reference to Figures 1A and 1B, the microfluidic device
(100) includes a rigid substrate (20) having a microchannel (40) formed on a surface
thereof and a flexible layer (10) coupled to and overlying the rigid substrate (20)
thereby enclosing the microchannel (40).
[0036] Also disclosed is a microfluidic device (100), which again with reference to Figures
1A and 1B, the reverse orientation is provided. In this instance microchannel (40)
is formed in flexible layer (10); and rigid substrate (20) is provided with a flat
surface profile, such that when flexible layer (10) is coupled to and overlying rigid
substrate (20) a microchannel (40) is formed therebetween.
[0037] In various embodiments, the flexible layer (10) comprises a raised element (30) disposed
over a portion or all of the microchannel (40). The raised element (30) provides an
increased cross-section thickness in the area which coincides with the microchannel
(40). This assists in creating a water tight seal between the deformed elastomeric
material (60) advanced into the microchannel (40) with the surface of the microchannel.
One skilled in the art would understand that the raised element (30) may be one of
a number of suitable shapes such as a bump. In other embodiments, the flexible layer
(10) has no raised element (30), in which case microchannel (40) is covered entirely
by flexible layer (10) which has a flat upper surface profile, which surface is not
in contact with rigid substrate (20).
[0038] One or more microchannels (40) may be formed on a surface of the rigid substrate
(20) by any number of suitable techniques known in the art. For example, microchannels
may be formed by deposition of materials through a mask, chemical etching, laser etching,
molding of a plastic substrate, and the like. A fluid tight seal is also formed between
the rigid substrate (20) and the flexible layer (10) along a periphery of the microchannel
(40) forming an enclosed capillary having a defined fluid flow path.
[0039] Microchannels may be dimensioned to define the volume within the microchannel and
resultant flow rate for a given rate at which the elastomer is progressively deformed
into the microchannel. The high quality and precision of the so formed microchannel
results in a microfluidic pump element that can achieve very slow and consistent flow
rates, which may not otherwise be achieved if alternate processes of manufacture were
employed. A microchannel may be dimensioned such that it has a constant width dimension
and a constant depth dimension along all or a portion of its length. In one embodiment,
a microchannel will have a constant width dimension and a constant depth dimension
along a length of the microchannel which engages a deformation element. In general,
a microchannel has a width dimension of between 500 to 900 microns and a depth dimension
of between 40 to 100 microns. As such, the device may be adapted for a flow rate within
the microchannel of between 0.001 µl/s to 5.0 µl/s.
[0040] Microchannels having a variety of cross-sectional geometries may be utilized. Figures
1A and 1B depict a microchannel (40) in which the bottom surface of the microchannel
is arced and defines a concave circular geometry. However, it will be understood that
the microchannel (40) may have a rounded, elliptical or generally U shaped bottom.
In one embodiment, the microchannel has an arced shaped bottom having a radius of
curvature of between 0.7 and 0.9 mm. Figure 2 is a cross-sectional view of a portion
of a microfluidic device in one embodiment of the invention in which specific dimensions
(shown in mm) are described for various features.
[0041] One skilled in the art would appreciate that the surfaces of microchannels (40) may
be modified, for example by varying hydrophobicity. For instance, hydrophobicity may
be modified by application of hydrophilic materials such as surface active agents,
application of hydrophobic materials, construction from materials having the desired
hydrophobicity, ionizing surfaces with energetic beams, and/or the like.
[0042] As discussed herein, a device of the present invention may include a plurality of
microchannels (40), each having various geometries and disposed on the rigid substrate
(20) (or in the alternate on the flexible layer (10)) in a variety of patterns. For
example, microchannels (40) may be linear or extend arcuately along the surface of
the rigid substrate (20). Figures 3 and 4 illustrate microchannels (40) being disposed
as generally circular or spiral geometries. Figure 3 is a perspective view of a device
in which microchannels (40) are disposed as spirals, a smaller volume microchannel
disposed within a microchannel having a larger volume. Figure 4 is a top view of a
device in which the microchannel (40) is disposed in a spiral manner having ports
(100) and (110) which may be in fluid communication with one or more additional microchannels
or structures. In one embodiment, the circular or spiral portion of the microchannel
has a length of between 20 to 100 mm.
[0043] A spiral or generally circular shaped microchannel allows for fluid to be advanced
through the microchannel of the pump module or device by a deformation element (50)
that is radially coupled to the device. Figure 5 is an illustration depicting a pump
module and device of the present invention in which multiple deformation elements
(50) are radially coupled and configured to engage a microchannel having a circular
or spiral geometry. The deformation elements (50) are provided in a housing (80) configured
to radially traverse one or more microchannels provided on the microfluidic laminate
structure (110) when the structure is placed in contact with the deformation elements
(50) (spiral microchannel is disposed on the opposite side of laminate structure (110)
shown). As will be appreciated by those of skill in the art, the rotational direction
of the deformation elements (50) with relation to the micro fluidic laminate structure
(110) dictates the direction of flow within the microchannel. As such, one skilled
in the art would appreciate that, advantageously, fluid flow through the pump may
be bidirectional.
[0044] Housing (80) may be rotated by applying a voltage to a motor controlling movement
thereof. As such, also disclosed is a method for performing a microfluidic process
which includes applying a voltage to a device as described herein. The applied voltage
activates a motor which advances at least one deformation element (50), such as one
or more rollers, which are rotatably engaged with the elastomeric first plate element
(10), causing deformation of a raised element (30) on the flexible layer (10) into
the microchannel (40) formed on the surface of the rigid substrate (20).
[0045] A wide range of pulses per second may be applied to the electrical motor thereby
effectuating a wide range of flow rates within microchannels. The fluid flow is essentially
constant, with little or no shear force being imposed on the fluid, even at very low
flow rates. These characteristics of the pump enhance the accuracy of analyses performed
with it (
e.g., analyte integrity is preserved by minimizing exposure of sample components to shear
and degradation), while low flow rates provide sufficient time for chemical reactions
to occur. A low, constant pumped flow rate can also be very useful in drug delivery,
to ensure dosing accuracy.
[0046] In one embodiment, between 100 and 10,000 pulses per second may be applied resulting
in a flow rate of between 0.001 µl/s to 5.0 µl/s through microchannels. The design
of the present invention allows forces within microchannels of the present invention
to remain fairly constant over a wide range of applied pulses.
[0047] For example, Figures 7-9 are graphs plotting forces generated within microchannels
as a function of the number of pulses per second. As depicted in the graphs of Figures
7-9, forces generated within the microchannels are relatively constant over a wide
range of pulses per second indicating substantially constant flow with minimal shear.
[0048] Figures 6A-6C illustrate various configurations in different embodiments of the invention
in which at least one spiral or circular microchannel is provided. Circular or spiral
microchannels (40) may be disposed such that they are in fluid communication with
one or more additional microchannels (140) through ports (100) and (110). Additional
microchannels (140) may be provided with various reagents, immobilized therein or
otherwise provided such that a biological assay may be performed on a fluid sample.
[0049] With reference to Figure 1, as discussed herein, a fluid tight seal is formed between
the rigid substrate (20) and the flexible layer (10) along a periphery of the microchannel
(40) forming an enclosed capillary having a defined fluid flow path. Figure 10, illustrates
a portion of a device having a generally spiral microchannel in which a fluid tight
seal (140) is shown along the periphery of the microchannel (40).
[0050] A variety of methods may be utilized to couple rigid substrate (20) to the elastomer
that forms flexible layer (10). The parts may be joined together using UV curable
adhesive or other adhesive that permits for movement of the two parts relative one
another prior to curing of the adhesive/creation of bond. Suitable adhesives include
a UV curable adhesive, a heat cured adhesive, a pressure sensitive adhesive, an oxygen
sensitive adhesive, and a double-sided tape adhesive.
[0051] Alternatively, the parts may be coupled utilizing a welding process. Such processes
including an ultrasonic welding process, a thermal welding process, and a torsional
welding process.
[0052] In a further alternative, the parts may be joined using a process of two-shot molding
or overmolding, in which case first one polymer and then the other is injected into
a mold tool. One of skill in the art will readily appreciate that elastomeric and
non-elastomeric polymers can be joined in this way to achieve fluid tight seals between
the parts.
[0053] A process of laser welding may be utilized. The process includes:
- (a) exposing one of the first or second plate elements to ultra violet laser energy
around the periphery of the microchannel so as to carbonize the surface of the first
or second plate element;
- (b) applying a compressive force between the first and second plate elements; and
- (c) exposing the compressed first and second plate elements to infra red laser energy
to cause localized heating and melting in the proximity of the carbonized surface
of (a) so as to seal the first and second plate elements, thereby forming a fluid
tight seal along the boundary of the microchannel.
[0054] The benefits of such approaches mean that (i) the parts may be manipulated (slid
against one another) during manufacture to achieve desired alignments, (ii) intricate
forms can be achieved in the non-elastomer - linear or arcuate channels (or combinations
thereof) with a plurality of channel geometries, (iii) connections with the device
may be made via the non-elastomeric material, which is dimensionally stable.
[0055] In various embodiments, additional microchannels and structures may be provided to
allow the device to perform a number of different types of biological assays or reactions.
For example, additional fluid or reagent reservoirs may be provided, one or more of
which act as a reaction chamber for example. Additional structure and depicted in
the following example which is intended to illustrate but not limit the invention.
[0056] The following embodiment describes the use of a planar circular or spiral peristaltic
pump of the present invention for use in low cost diagnostic products consisting of
an instrument and consumable, where the consumable requires sealing due to a potential
high risk of contamination.
[0057] Two aspects are described. First, a very low cost method to perform pumping a liquid
sample to stored dry chemicals which are deposited at a location internal to the consumable,
followed by mixing of the liquid sample with the stored chemicals. Second, dilution
of chemicals using the same active pumping system where the dilution step occurs part
way through the diagnostic process.
[0058] The two aspects may be used together or individually. They shall now be described
separately with reference to Figures 11-13. Reference numerals for features of Figures
11-13 as used in this Example are specific for each Figure and may be represented
by another numeral in Figures 1-10 of this application.
[0059] With reference to Figure 11, the method to perform pumping sample fluids to deposited
chemicals followed by mixing of sample fluid with deposited chemicals in a low cost
manner involves using only one actuator, for example a DC or stepper motor (1) incorporated
into the instrument. The peristaltic pump consists of a planar circular or spiral
annular microchannel (2) as a feature of a substrate (3) of the consumable (4) and
the deforming membrane of the pump is provided by an elastomeric layer (5) which is
deformed by the pump rollers (6). Concentric to the annular pump channels is the mixing
chamber (7) which contains a magnetic or magnetized puck (8). Concentric to the pump
rollers of the instrument is a structure comprising a mixing head (9) which is magnetic
or magnetized and is magnetically coupled to the puck.
[0060] By providing inlet and outlet ports to the mixing chamber from the pump microchannels,
the pump and mixing chamber are fluidically connected, thus fluid can be pumped from
the pump microchannels into the mixing chamber as the motor rotates in a predetermined
direction. The instrument component of the pump comprises a suitable mechanism to
provide pumping and mixing functionality when the motor is rotated in a certain direction,
but only mixing functionality when the motor is rotated in the opposite direction,
for example a ratchet system implemented by a pawl (10) and a compression spring (11)
whereby the mixing head rotates with the pump rollers in one rotational direction
of the motor and whereby the pump rollers disengage from the motor when the motor
rotates in the other direction, thus providing rotation of the mixing head only. The
compression spring may also provide the necessary contact force on the pump channels
to facilitate effective pumping. A sequence of events is provided in Table 1 below.
Table 1.
| Motor Operation |
Effect on fluid |
| Motor rotates clockwise |
Pump rotor is engaged and sample fluid is transported from one location on the consumable
into the mixing chamber. Magnetic force to the puck is also provided. |
| Motor stops |
Transportation of sample fluid is stopped. |
| Motor rotates counter clockwise |
Pump rotor is disengaged and sample fluid remains in mixing chamber. Only the puck
moves due to magnetic force and sample is mixed with deposited chemicals. |
| Motor rotates clockwise |
Pump rotor is engaged and chemicals mixed with sample fluid are transported from the
mixing chamber to another location on the consumable. |
[0061] Another embodiment provides an annular mixing chamber internal or external to the
pump channels. This embodiment could feasibly be produced at a lower cost than the
first embodiment and is described with reference to Figure 12. The spiral or circular
pump channel (1) as a feature in a substrate (2) is overlaid with an elastomeric membrane
(3) and deformed by pump rollers (4) in a similar manner to that described in Figure
11. However, in this particular embodiment the mixing chamber is an annular channel
(4) as a concentric feature to the pump channel but located on the reverse face of
the pump channel substrate.
[0062] Located within this annular channel is one or many bearing balls (5) which are magnetically
coupled to a magnetic or magnetized element on the rotor (6) such that as the rotor
rotates the bearing balls also rotate in the annular channel, thus providing mixing
of chemicals initially deposited inside the annular channel. The drive mechanism to
achieve mixing and pumping in one rotational direction of the motor and just mixing
in the other rotational direction of the motor is envisaged to be similar to that
described with reference to Figure 11.
[0063] With reference to Figure 13 and including features of the motor drive system described
in the sections above, the method to perform a dilution step during the diagnostic
test using the circular or spiral peristaltic pump is described: Two concentric circular
or spiral pump channels, are included in the consumable each having their own fluid
path, for example, the inner microchannel (1) provides fluidic pumping of the sample
fluid (2) and the outer microchannel (3) provides fluidic pumping for a dilution fluid
(4). Each microchannel shares the same pump rollers (5), such that rotation of the
drive shaft by the low cost motor causes both sample fluid and buffer fluid to be
pumped.
[0064] Should more fluids be required to be pumped in separate channels, this peristaltic
pump can be designed to accommodate multiple fluidic channels on different radii if
desired. In this embodiment the sample that is transported is first required to be
mixed with stored deposited chemicals (6) located within the mixing chamber (7), followed
by a dilution step using a dilution fluid.
[0065] It is preferable to store the dilution fluid away from the stored chemicals so the
stored chemicals do not become affected by the dilution fluid. When the motor rotates
in a certain direction the pump rollers engage with the pumping membrane to transport
both sample fluid and dilution fluid into the consumable, as the mixing chamber fills
with sample fluid, the dilution fluid fills a secondary chamber (8) which is sized
according to the amount of dilution fluid required and the geometry of the dilution
fluid pumping channels and the mixing chamber volume. When the motor stops both dilution
fluid and sample fluid remain in their respective chambers.
[0066] If mixing is required, an equivalent mechanism as described above could be implemented
which rotates the motor in the opposite direction to only provide mixing. When the
sample fluid and dilution fluid are required to be combined, the motor rotates to
engage the pump rollers which transport the sample and dilution fluid to a location
inside the consumable which combines the two fluids (9). To assist combining the two
fluids, passive mixing features (10) may be included at the fluid combining region.
As the motor continues to rotate to pump the two fluids, the diluted sample can be
transported to another location on the consumable, for example a location to carry
out detection of an analyte (11).
[0067] Several advantages are provided by the invention. First, manufacturing costs are
lowered due to the function and form of the circular or spiral peristaltic pump design.
Aspects of the pump design which make this possible are circular or spiral geometry
allows for the use of only one actuator; in this embodiment it is an electric motor,
such that rotating the motor in one direction performs a different function to rotating
the motor in the opposite direction. An additional feature of the pump design is the
ability for the consumable part of the pump to include multiple pump channels such
that multiple fluids may be transported using the same motor drive mechanism.
[0068] If a chemical reaction, such as an amplification reaction, is performed which could
result in contamination, or if the potential for contamination is to be removed for
other reasons, then the pump design allows the pump to be sealed to the environment.
[0069] A wide range of pulses per second may be applied to the electrical motor thereby
effectuating a wide range of flow rates within microchannels, including very low flow
rates. The fluid flow is essentially constant, with little or no shear force being
imposed on the fluid, even at very low flow rates. These characteristics of the pump
enhance the accuracy of analyses performed with it (
e.g., analyte integrity is preserved by minimizing exposure of sample components to shear
and degradation), while low flow rates provide sufficient time for chemical reactions
to occur. A low, constant pumped flow rate can also be very useful in drug delivery,
to ensure dosing accuracy.
[0070] Although the invention has been described it will be understood that modifications
and variations are encompassed within the scope of the invention. Accordingly, the
invention is limited only by the following claims.
1. A microfluidic pump, comprising:
a microchannel (40) defined by (a) a groove (1, 40) in a first surface of a first
substrate (20), and (b) a second surface of a second substrate (10); and
an actuator (50) configured to compress a portion of the second substrate (10) into
the groove of the first substrate (20) without substantially deforming the groove
(1, 40), characterised in that the actuator (50) is configured to translate along an axis of the groove (1, 40).
2. The pump of claim 1, wherein the groove (1, 40) has a height and the height is at
least about 10 microns, at least about 20 microns, at least about 30 microns, or at
least about 50 microns and/or wherein the groove (1, 40) has a height and the height
is about 1000 microns or less, about 500 microns or less, about 250 microns or less,
about 125 microns or less, about 100 microns or less, about 75 microns or less.
3. The pump of any of the foregoing claims, wherein the first and second substrates (20,
10) are substantially planar.
4. The pump of any of the foregoing claims, wherein the channel has an inlet and an outlet
and a distance between the inlet and the outlet is at least about 1 mm, at least about
2.5 mm, at least about 5 mm, at least about 10 mm, at least about 25 mm and/or wherein
the channel has an inlet and an outlet and a distance between the inlet and the outlet
is about 250 mm or less, 100 mm or less, about 75 mm or less, about 50 mm or less,
about 25 mm or less.
5. The pump of any of the foregoing claims, wherein the pump is disposed in fluidic communication
with a microfluidic device
6. The pump of claim 5, wherein the pump comprises at least one microchannel (1, 40)
configured to receive a liquid sample suspected of containing at least one target
and the microchannel (1, 40) comprises at least one reagent for use in determining
the presence of the at least one target.
7. The pump of claim 6, wherein the pump is configured to produce a gas pressure acting
upon a distal gas-liquid interface of the liquid sample when the distal gas-liquid
interface of the liquid sample is disposed within the microchannel (1, 40) of the
microfluidic device.
8. The pump of claim 7, wherein a proximal gas-liquid interface of the liquid sample
is exposed to an ambient atmosphere.
9. The pump of claim 7 or claim 8, wherein the gas pressure acting upon the distal gas-liquid
interface of the liquid sample is less than an ambient gas pressure.
10. The pump of any of claims 5-9, wherein the first and second substrates (20, 10) are
disposed within the microfluidic device.
11. The pump of any of claims 5-10, wherein the microchannel (1, 40) of the microfluidic
device comprises the liquid sample disposed therein, optionally wherein the liquid
sample comprises urine or at least one liquid component of blood.
12. The pump of any of claims 5-11, wherein the actuator (50) is configured to provide
a rate of flow of the liquid sample within the microchannel (1, 40) of the microfluidic
device of at least about 1 nl/s, at least about 5 nl/s, at least about 10 nl/s, at
least about 25 nl/s, at least about 50 nl/s, at least about 100 nl/s, at least about
250 nl/s, at least about 500 nl/s at least about 1000 nl/s and/or wherein the actuator
(50) is configured to provide a rate of flow of the liquid sample within the microchannel
(1, 40) of the microfluidic device of about 10,000 nl/s or less, about 5,000 nl/s
or less, about 2,500 nl/s or less, at least about 1000 nl/s or less.
13. The pump of any of claims 5-12, wherein a total volume of liquid sample within the
microchannel (1, 40) is about 100 microliters or less, about 50 microliters or less,
about 25 microliters or less, about 20 microliters or less.
14. The pump of any of the foregoing claims, wherein the channel has an uncompressed area
and, when compressed by the actuator (50), the compressed portion of the second substrate
(10) occludes at least about 50%, at least about 75%, at least about 90%, at least
about 95%, at least about 97.5%, at least about 99%, or essentially all of the uncompressed
area of the channel.
15. The pump of any of the foregoing claims, wherein in the uncompressed state, the groove
(1, 40) has a width and the width is at least about 50 microns, at least about 100
microns, at least about 200 microns, at least about 500 microns, optionally wherein,
in the compressed state, the width of the groove (1, 40) is at least about 75%, at
least about 90%, at least about 95%, at least about 97.5%, at least about 99%, or
essentially the same as in the uncompressed state.
16. The pump of any of the foregoing claims, wherein, in the compressed state, the groove
(1, 40) has a width and the width is about 2000 microns or less, about 1500 microns
or less, about 1000 microns or less, about 750 microns or less about 600 microns or
less, optionally wherein, in the compressed state, the height of the groove (1, 40)
is at least about 75%, at least about 90%, at least about 95%, at least about 97.5%,
at least about 99%, or essentially the same as in the uncompressed state.
17. The pump of any of the foregoing claims, wherein, in the uncompressed state, the second
substrate (10) has a first thickness overlying the groove (1, 40) and a second thickness
spaced apart laterally a first distance from the groove (1, 40) and wherein the second
thickness is at least about 110%, at least about 125%, at least about 150%, at least
about 175%, or at least about 200% greater than the first thickness, optionally wherein
the first distance is at about 50% greater than a width of the groove (1, 40), about
75% greater than a width of the groove (1, 40), about 100% greater than a width of
the groove(1, 40), about 200% greater than a width of the groove (1, 40).
1. Mikrofluidische Pumpe, die Folgendes umfasst:
einen Mikrokanal (40), definiert durch (a) eine Nut (1, 40) in einer ersten Oberfläche
eines ersten Substrats (20), und (b) eine zweite Oberfläche eines zweiten Substrats
(10); und
einen Aktuator (50), ausgelegt zum Eindrücken eines Teils des zweiten Substrats (10)
in die Nut des ersten Substrats (20), ohne die Nut (1, 40) wesentlich zu verformen,
dadurch gekennzeichnet, dass
der Aktuator (50) dazu ausgelegt ist, sich entlang einer Achse der Nut (1, 40) zu
verschieben.
2. Pumpe nach Anspruch 1, wobei die Nut (1, 40) eine Höhe hat und die Höhe mindestens
etwa 10 Mikrometer, mindestens etwa 20 Mikrometer, mindestens etwa 30 Mikrometer oder
mindestens etwa 50 Mikrometer ist und/oder wobei die Nut (1, 40) eine Höhe hat und
die Höhe etwa 1000 Mikrometer oder weniger, etwa 500 Mikrometer oder weniger, etwa
250 Mikrometer oder weniger, etwa 125 Mikrometer oder weniger, etwa 100 Mikrometer
oder weniger, etwa 75 Mikrometer oder weniger ist.
3. Die Pumpe nach einem der vorhergehenden Ansprüche, wobei das erste und das zweite
Substrat (20, 10) im Wesentlichen eben sind.
4. Pumpe nach einem der vorhergehenden Ansprüche, wobei der Kanal einen Einlass und einen
Auslass aufweist und ein Abstand zwischen dem Einlass und dem Auslass mindestens etwa
1 mm, mindestens etwa 2,5 mm, mindestens etwa 5 mm, mindestens etwa 10 mm, mindestens
etwa 25 mm ist und/oder wobei der Kanal einen Einlass und einen Auslass aufweist und
ein Abstand zwischen dem Einlass und dem Auslass etwa 250 mm oder weniger, 100 mm
oder weniger, etwa 75 mm oder weniger, etwa 50 mm oder weniger, etwa 25 mm oder weniger
ist.
5. Pumpe nach einem der vorhergehenden Ansprüche, wobei die Pumpe in Fluidverbindung
mit einer mikrofluidischen Vorrichtung angeordnet ist.
6. Pumpe nach Anspruch 5, wobei die Pumpe mindestens einen Mikrokanal (1, 40) umfasst,
der dazu ausgelegt ist, eine Flüssigkeitsprobe aufzunehmen, von der vermutet wird,
dass sie zumindest ein Ziel enthält, und wobei der Mikrokanal (1, 40) zumindest ein
Reagens zur Verwendung beim Bestimmen der Anwesenheit des zumindest einen Ziels umfasst.
7. Pumpe nach Anspruch 6, wobei die Pumpe dazu ausgelegt ist, einen Gasdruck zu erzeugen,
der auf eine distale Gas-Flüssigkeit-Schnittstelle der Flüssigkeitsprobe wirkt, wenn
die distale Gas-Flüssigkeit-Schnittstelle der Flüssigkeitsprobe innerhalb des Mikrokanals
(1, 40) der mikrofluidischen Vorrichtung angeordnet ist.
8. Pumpe nach Anspruch 7, wobei eine proximale Gas-Flüssigkeit-Schnittstelle der Flüssigkeitsprobe
einer umgebenden Atmosphäre ausgesetzt ist.
9. Pumpe nach Anspruch 7 oder Anspruch 8, wobei der Gasdruck, der auf die distale Gas-Flüssigkeit-Schnittstelle
der Flüssigkeitsprobe wirkt, kleiner als ein umgebender Gasdruck ist.
10. Pumpe nach einem der Ansprüche 5-9, wobei das erste und das zweite Substrat (20, 10)
innerhalb der mikrofluidischen Vorrichtung angeordnet sind.
11. Pumpe nach einem der Ansprüche 5-10, wobei der Mikrokanal (1, 40) der mikrofluidischen
Vorrichtung die darin angeordnete Flüssigkeitsprobe umfasst, wobei optional die Flüssigkeitsprobe
Urin oder zumindest eine flüssige Komponente von Blut umfasst.
12. Pumpe nach einem der Ansprüche 5-11, wobei der Aktuator (50) dazu ausgelegt ist, eine
Durchflussrate der Flüssigkeitsprobe innerhalb des Mikrokanals (1, 40) der mikrofluidischen
Vorrichtung von mindestens etwa 1 nl/s, mindestens etwa 5 nl/s, mindestens etwa 10
nl/s, mindestens etwa 25 nl/s, mindestens etwa 50 nl/s, mindestens etwa 100 nl/s,
mindestens etwa 250 nl/s, mindestens etwa 500 nl/s, mindestens etwa 1000 nl/s bereitzustellen
und/oder wobei der Aktuator (50) dazu ausgelegt ist, eine Durchflussrate der Flüssigkeitsprobe
innerhalb des Mikrokanals (1, 40) der mikrofluidischen Vorrichtung von etwa 10.000
nl/s oder weniger, etwa 5.000 nl/s oder weniger, etwa 2.500 nl/s oder weniger, zumindest
etwa 1000 nl/s oder weniger bereitzustellen.
13. Pumpe nach einem der Ansprüche 5-12, wobei ein Gesamtvolumen der Flüssigkeitsprobe
innerhalb des Mikrokanals (1, 40) etwa 100 Mikroliter oder weniger, etwa 50 Mikroliter
oder weniger, etwa 25 Mikroliter oder weniger, etwa 20 Mikroliter oder weniger ist.
14. Pumpe nach einem der vorhergehenden Ansprüche, wobei der Kanal einen nicht eingedrückten
Bereich umfasst und wobei, wenn durch den Aktuator (50) eingedrückt, der eingedrückte
Teil des zweiten Substrats (10) mindestens etwa 50 %, mindestens etwa 75 %, mindestens
etwa 90 %, mindestens etwa 95 %, mindestens etwa 97,5 %, mindestens etwa 99 % oder
im Wesentlichen den gesamten nicht eingedrückten Bereich des Kanals bedeckt.
15. Pumpe nach einem der vorhergehenden Ansprüche, wobei, im nicht eingedrückten Zustand,
die Nut (1, 40) eine Breite hat, und wobei die Breite mindestens etwa 50 Mikrometer,
mindestens etwa 100 Mikrometer, mindestens etwa 200 Mikrometer, mindestens etwa 500
Mikrometer ist, wobei optional, im eingedrückten Zustand die Breite der Nut (1, 40)
mindestens etwa 75 %, mindestens etwa 90 %, mindestens etwa 95 %, mindestens etwa
97,5 %, mindestens etwa 99 % oder im Wesentlichen die gleiche wie im nicht eingedrückten
Zustand ist.
16. Pumpe nach einem der vorhergehenden Ansprüche, wobei, im eingedrückten Zustand, die
Nut (1, 40) eine Breite hat, und wobei die Breite etwa 2000 Mikrometer oder weniger,
etwa 1500 Mikrometer oder weniger, etwa 1000 Mikrometer oder weniger, etwa 750 Mikrometer
oder weniger, etwa 600 Mikrometer oder weniger ist, wobei optional, im eingedrückten
Zustand die Höhe der Nut (1, 40) mindestens etwa 75 %, mindestens etwa 90 %, mindestens
etwa 95 %, mindestens etwa 97,5 %, mindestens etwa 99 % oder im Wesentlichen die gleiche
wie im nicht eingedrückten Zustand ist.
17. Pumpe nach einem der vorhergehenden Ansprüche, wobei, im nicht eingedrückten Zustand,
das zweite Substrat (10) eine erste Dicke hat, die über der Nut (1, 40) liegt, und
eine zweite Dicke hat, die lateral um einen ersten Abstand von der Nut (1, 40) beabstandet
ist und wobei die zweite Dicke mindestens etwa 110 %, mindestens etwa 125 %, mindestens
etwa 150 %, mindestens etwa 175 % oder mindestens etwa 200 % größer als die erste
Dicke ist, wobei optional der erste Abstand etwa 50 % größer als eine Breite der Nut
(1, 40), etwa 75 % größer als eine Breite der Nut (1, 40), etwa 100 % größer als eine
Breite der Nut (1, 40), etwa 200 % größer als eine Breite der Nut (1, 40) ist.
1. Pompe fluidique, comprenant :
un microcanal (40) défini par (a) une rainure (1, 40) dans une première surface d'un
premier substrat (20), et (b) une seconde surface d'un second substrat (10) ; et
un actionneur (50) configuré pour comprimer une partie du second substrat (10) dans
la rainure du premier substrat (20) sans déformer sensiblement la rainure (1, 40),
caractérisée en ce que l'actionneur (50) est configuré pour effectuer une translation le long d'un axe de
la rainure (1, 40).
2. Pompe selon la revendication 1, dans laquelle la rainure (1, 40) a une hauteur et
la hauteur est d'au moins environ 10 microns, d'au moins environ 20 microns, d'au
moins environ 30 microns, ou d'au moins environ 50 microns et/ou dans laquelle la
rainure (1, 40) a une hauteur et la hauteur est d'environ 1000 microns ou moins, d'environ
500 microns ou moins, d'environ 250 microns ou moins, d'environ 125 microns ou moins,
d'environ 100 microns ou moins, d'environ 75 microns ou moins.
3. Pompe selon l'une quelconque des revendications précédentes, dans laquelle les premier
et second substrats (20, 10) sont sensiblement plans.
4. Pompe selon l'une quelconque des revendications précédentes, dans laquelle le canal
a une entrée et une sortie et une distance entre l'entrée et la sortie est d'au moins
environ 1 mm, d'au moins environ 2,5 mm, d'au moins environ 5 mm, d'au moins environ
10 mm, d'au moins environ 25 mm et/ou dans laquelle le canal a une entrée et une sortie
et une distance entre l'entrée et la sortie est d'environ 250 mm ou moins, de 100
mm ou moins, d'environ 75 mm ou moins, d'environ 50 mm ou moins, d'environ 25 mm ou
moins.
5. Pompe selon l'une quelconque des revendications précédentes, la pompe étant disposée
en communication fluidique avec un dispositif microfluidique.
6. Pompe selon la revendication 5, la pompe comprenant au moins un microcanal (1, 40)
configuré pour recevoir un échantillon liquide suspecté de contenir au moins une cible
et le microcanal (1, 40) comprenant au moins un réactif à utiliser pour déterminer
la présence de l'au moins une cible.
7. Pompe selon la revendication 6, la pompe étant configurée pour produire une pression
de gaz agissant sur une interface gaz-liquide distale de l'échantillon liquide lorsque
l'interface gaz-liquide distale de l'échantillon liquide est disposée dans le microcanal
(1, 40) du dispositif microfluidique.
8. Pompe selon la revendication 7, dans laquelle une interface gaz-liquide proximale
de l'échantillon liquide est exposée à une atmosphère ambiante.
9. Pompe selon la revendication 7 ou la revendication 8, dans laquelle la pression de
gaz agissant sur l'interface gaz-liquide distale de l'échantillon liquide est inférieure
à une pression de gaz ambiant.
10. Pompe selon l'une quelconque des revendications 5 à 9, dans laquelle les premier et
second substrats (20, 10) sont disposés à l'intérieur du dispositif microfluidique.
11. Pompe selon l'une quelconque des revendications 5 à 10, dans laquelle le microcanal
(1, 40) du dispositif microfluidique comprend l'échantillon liquide disposé dans celui-ci,
éventuellement dans laquelle l'échantillon liquide comprend de l'urine ou au moins
un composant liquide du sang.
12. Pompe selon l'une quelconque des revendications 5 à 11, dans laquelle l'actionneur
(50) est configuré pour fournir un débit de l'échantillon liquide dans le microcanal
(1, 40) du dispositif microfluidique d'au moins environ 1 nl/s, d'au moins environ
5 nl/s, d'au moins environ 10 nl/s, d'au moins environ 25 nl/s, d'au moins environ
50 nl/s, d'au moins environ 100 nl/s, d'au moins environ 250 nl/s, d'au moins environ
500 nl/s, d'au moins environ 1000 nl/s et/ou dans laquelle l'actionneur (50) est configuré
pour fournir un débit de l'échantillon liquide dans le microcanal (1, 40) du dispositif
microfluidique d'environ 10 000 nl/s ou moins, d'environ 5000 nl/s ou moins, d'environ
2500 nl/s ou moins, d'au moins environ 1000 nl/s ou moins.
13. Pompe selon l'une quelconque des revendications 5 à 12, dans laquelle un volume total
d'échantillon liquide dans le microcanal (1, 40) est d'environ 100 microlitres ou
moins, d'environ 50 microlitres ou moins, d'environ 25 microlitres ou moins, d'environ
20 microlitres ou moins.
14. Pompe selon l'une quelconque des revendications précédentes, dans laquelle le canal
présente une zone non comprimée et, lorsqu'elle est comprimée par l'actionneur (50),
la partie comprimée du second substrat (10) occulte au moins environ 50 %, au moins
environ 75 %, au moins environ 90 %, au moins environ 95 %, au moins environ 97,5
%, au moins environ 99 %, ou essentiellement toute la zone non comprimée du canal.
15. Pompe selon l'une quelconque des revendications précédentes, dans laquelle, à l'état
non comprimé, la rainure (1, 40) a une largeur et la largeur est d'au moins environ
50 microns, d'au moins environ 100 microns, d'au moins environ 200 microns, d'au moins
environ 500 microns, éventuellement dans laquelle, à l'état comprimé, la largeur de
la rainure (1, 40) est d'au moins environ 75 %, d'au moins environ 90 %, d'au moins
environ 95 %, d'au moins environ 97,5 %, d'au moins environ 99 %, ou essentiellement
la même qu'à l'état non comprimé.
16. Pompe selon l'une quelconque des revendications précédentes, dans laquelle, à l'état
comprimé, la rainure (1, 40) a une largeur et la largeur est d'environ 2000 microns
ou moins, d'environ 1500 microns ou moins, d'environ 1000 microns ou moins, d'environ
750 microns ou moins, d'environ 600 microns ou moins, éventuellement dans laquelle,
à l'état comprimé, la hauteur de la rainure (1, 40) est d'au moins environ 75 %, d'au
moins environ 90 %, d'au moins environ 95 %, d'au moins environ 97,5 %, d'au moins
environ 99 %, ou essentiellement la même qu'à l'état non comprimé.
17. Pompe selon l'une quelconque des revendications précédentes, dans laquelle, à l'état
non comprimé, le second substrat (10) a une première épaisseur recouvrant la rainure
(1, 40) et une seconde épaisseur espacée latéralement d'une première distance de la
rainure (1, 40) et dans laquelle la seconde épaisseur est d'au moins environ 110 %,
d'au moins environ 125 %, d'au moins environ 150 %, d'au moins environ 175 %, ou d'au
moins environ 200 % plus grande que la première épaisseur, éventuellement dans laquelle
la première distance est environ 50 % plus grande qu'une largeur de la rainure (1,
40), environ 75 % plus grande qu'une largeur de la rainure (1, 40), environ 100 %
plus grande qu'une largeur de la rainure (1, 40), environ 200 % plus grande qu'une
largeur de la rainure (1, 40).