Microfluidic devices

Abstract

The separation assembly comprises a microfluidic separation element having a substrate layer. The microfluidic separation element defines an element inlet, a first element outlet, and a second element outlet. The first element outlet is defined by the substrate layer. The permeate discharge layer abuts the substrate layer. The permeate discharge layer is located downstream of the first element outlet.

Description

Technical Field

[0001] Priority This application claims priority to U.S. Provisional Application No. 63 / 455,886, filed Mar. 30, 2023, the disclosure of which is hereby incorporated by reference in its entirety.

[0002] The present disclosure generally relates to microfluidic devices. More specifically, the present disclosure relates to microfluidic devices as particle separators.

Summary of the Invention

Means for Solving the Problems

[0003] Some embodiments of the technology disclosed herein relate to a separation assembly having a microfluidic separation element with a substrate layer. The microfluidic separation element defines an element inlet, a plurality of first element outlets, and a second element outlet. The plurality of first element outlets are defined by the substrate layer. A permeate discharge layer abuts the substrate layer. The permeate discharge layer is located downstream of the plurality of first element outlets.

[0004] In some such embodiments, the permeate discharge layer extends laterally across the substrate layer. Further, or alternatively, the separation assembly is a component of a cell retention device of a perfusion bioreactor. Further, or alternatively, the microfluidic separation element is a hydrodynamic separator element. Further, or alternatively, the permeate discharge layer is defined by a mesh material. Further, or alternatively, the permeate discharge layer is a material layer that defines a microchannel downstream of the plurality of first layer outlets. Further, or alternatively, the separation assembly further has a first microfluidic channel that defines a channel inlet downstream of the element inlet and a channel outlet having a first channel outlet upstream of a first one of the plurality of first element outlets and a second channel outlet upstream of the second element outlet. Further, or alternatively, the first microfluidic channel is curved.

[0005] Furthermore, or alternatively, the separation assembly has a plurality of microfluidic channels, each having a first microfluidic channel. Each microfluidic channel defines a channel inlet downstream of an element inlet, a first channel outlet upstream of a first element outlet among a plurality of first element outlets, and a second channel outlet upstream of a second element outlet. Furthermore, or alternatively, each of the plurality of microfluidic channels is nested with adjacent microfluidic channels. Furthermore, or alternatively, the plurality of microfluidic channels has at least six microfluidic channels. Furthermore, or alternatively, each microfluidic channel is within 12 mm, 10 mm, 5 mm, or 3 mm of an adjacent microfluidic channel. Furthermore, or alternatively, each microfluidic channel is curved. Furthermore, or alternatively, each microfluidic channel defines two curves in opposite directions. Furthermore, or alternatively, each microfluidic channel has an inner wall and an outer wall, and each microfluidic channel is configured to concentrate particles in the liquid stream toward the inner wall. Furthermore, or alternatively, the length of each of the multiple microfluidic channels defines an arc of 270° or less.

[0006] Some embodiments of this technology relate to a system having multiple isolation assemblies consistent with those described above, where the isolation assemblies are arranged in a stack configuration. The system inlet is in direct fluid communication with each element inlet. The isolation assemblies are arranged to operate in parallel.

[0007] Furthermore, or alternatively, the length of each of the multiple microfluidic channels defines an arc of 200° or less. Furthermore, or alternatively, the microfluidic separation element is configured to separate particles in the range of 10–20 microns from the liquid stream. Furthermore, or alternatively, the microfluidic separation element is configured to separate one or both fish cells and bird cells in the liquid stream. Furthermore, or alternatively, the microfluidic separation element is configured to separate one or both mammalian cells and insect cells in the liquid stream.

[0008] Some embodiments of the technology disclosed herein relate to a hydrodynamic separator element having a substrate layer defining a layer inlet, a plurality of first and second layer outlets, an outlet channel upstream of the second layer outlet, and a plurality of curved microfluidic channels arranged to operate in parallel. Each microfluidic channel defines a channel inlet downstream of the layer inlet, a first channel outlet upstream of the first of the plurality of first layer outlets, and a second channel outlet upstream of the outlet channel. The substrate layer is impermeable. Each of the plurality of microfluidic channels is nested with adjacent microfluidic channels.

[0009] In some such embodiments, the length of each of the multiple curved microfluidic channels defines an arc of 270° or less. Furthermore, or alternatively, the length of each of the multiple curved microfluidic channels defines an arc of 200° or less. Furthermore, or alternatively, each microfluidic channel defines two curves in opposite directions. Furthermore, or alternatively, the multiple curved microfluidic channels consist of at least six microfluidic channels. Furthermore, or alternatively, each microfluidic channel is within 10 mm, 5 mm, or 3 mm of an adjacent microfluidic channel. Furthermore, or alternatively, the hydrodynamic separator element further has a permeate discharge layer in contact with the substrate layer. The permeate discharge layer is located downstream of the first layer outlet.

[0010] Furthermore, or alternatively, the permeate discharge layer extends laterally across the substrate layer. Furthermore, or alternatively, the permeate discharge layer is defined by a mesh material. Furthermore, or alternatively, the permeate discharge layer is a material layer defining microchannels downstream of a plurality of first layer outlets. Furthermore, or alternatively, the hydrodynamic separator element is a component of the cell retention device of the perfusion bioreactor. Furthermore, or alternatively, each microfluidic channel has an inner wall and an outer wall, and each microfluidic channel is configured to concentrate particles in the liquid stream toward the inner wall. Furthermore, or alternatively, the hydrodynamic separator element is configured to separate particles in the range of 10-20 microns from the liquid stream. Furthermore, or alternatively, the hydrodynamic separator element is configured to separate one or both fish cells and bird cells in the liquid stream. Furthermore, or alternatively, the hydrodynamic separator element is configured to separate one or both mammalian cells and insect cells in the liquid stream.

[0011] Furthermore, or alternatively, the hydrodynamic separator element has multiple substrate layers in a stacked configuration. The system inlet is in direct fluid communication with each layer inlet, and the multiple substrate layers are arranged to operate in parallel. Furthermore, or alternatively, a permeate discharge layer abuts each substrate layer, and each permeate discharge layer is located downstream of the corresponding first layer outlet.

[0012] Some embodiments of the technology disclosed herein relate to a system having a hydrodynamic separator element, the hydrodynamic separator element having an element inlet, a plurality of first element outlets, a second element outlet, and a plurality of curved microfluidic channels between the element inlet and the first element outlets. Each curved microfluidic channel has an inner wall and an outer wall, and the hydrodynamic separator element is configured to concentrate particles along the inner wall. A tangential flow filter has a feed inlet downstream of the plurality of first element outlets, a retaining liquid outlet, a permeate outlet, and a filter medium positioned between the feed inlet and the permeate outlet.

[0013] In some such embodiments, the system further includes a cell culture tank positioned downstream of the tangential flow filter. Furthermore, or alternatively, the hydrodynamic separator element has a substrate layer defining a layer inlet, a plurality of first layer outlets, and a second layer outlet. The layer inlet is located downstream of the element inlet, each first layer outlet is located upstream of the first element outlet among the plurality of first element outlets, and the second layer outlet is located upstream of the second element outlet. Each of the plurality of curved microfluidic channels extends between the layer inlet and the first layer outlet among the plurality of first layer outlets. Furthermore, or alternatively, the system further includes a permeate discharge layer abutting the substrate layer. The permeate discharge layer is located downstream of the first layer outlets.

[0014] Furthermore, or alternatively, the permeate discharge layer extends laterally across the substrate layer. Furthermore, or alternatively, the hydrodynamic separator element has multiple substrate layers in a stacked configuration. Each substrate layer defines a layer inlet, a plurality of first layer outlets, a second layer outlet, and a curved microfluidic channel extending between the layer inlet and the first layer outlet of the plurality of first layer outlets. Each layer inlet is located downstream of the element inlet, each first layer outlet is located upstream of the first element outlet of the plurality of first element outlets, and each second layer outlet is located upstream of the second element outlet. Furthermore, or alternatively, the system further has a permeate discharge layer abutting each substrate layer. The permeate discharge layer is located downstream of the corresponding first layer outlet. Furthermore, or alternatively, each permeate discharge layer extends laterally across the corresponding substrate layer. Furthermore, or alternatively, the permeate discharge layer is a material layer defining a microchannel downstream of the plurality of first layer outlets. Furthermore, or alternatively, the permeate discharge layer is defined by a mesh material. Furthermore, or alternatively, each substrate layer defines multiple curved microfluidic channels, each extending between the layer inlet and one of the first layer outlets among a plurality of first layer outlets.

[0015] Furthermore, or alternatively, each of the multiple microfluidic channels is nested with an adjacent microfluidic channel. Furthermore, or alternatively, each substrate layer has at least six microfluidic channels. Furthermore, or alternatively, each microfluidic channel is within 12 mm, 10 mm, 5 mm, or 3 mm of an adjacent microfluidic channel within each substrate layer. Furthermore, or alternatively, each microfluidic channel defines two curves in opposite directions. Furthermore, or alternatively, the length of each of the multiple curved microfluidic channels defines an arc of 270° or less.

[0016] Furthermore, or alternatively, the length of each of the multiple curved microfluidic channels defines an arc of 200° or less. Furthermore, or alternatively, the hydrodynamic separator element is configured to separate particles with a diameter of 10-20 micrometers from the liquid stream. Furthermore, or alternatively, the hydrodynamic separator element is configured to separate one or both fish cells and bird cells in the liquid stream. Furthermore, or alternatively, the hydrodynamic separator element is configured to separate one or both mammalian cells and insect cells in the liquid stream.

[0017] The above summary is not intended to describe each or all embodiments. Rather, a more complete understanding of the exemplary embodiments will become clear and apparent by referring to the following detailed description of exemplary embodiments and claims, while referring to the accompanying drawings.

[0018] This technology will be more fully understood and recognized by considering the following detailed descriptions of various embodiments in relation to the attached drawings. [Brief explanation of the drawing]

[0019] [Figure 1] This is a schematic diagram of an exemplary microfluidic device that is consistent with the technology disclosed herein. [Figure 2] Figure 1 shows a perspective view of some exemplary microfluidic separator elements that can be used in the device. [Figure 3] It is a detailed view of FIG. 2. [Figure 4] It is a cross-sectional view of an exemplary flow channel that conforms to the technology disclosed in this specification. [Figure 5] It is a side view of a plurality of flow channels that conform to the technology disclosed in this specification. [Figure 6] It is a perspective cross-sectional view of a part of an exemplary microfluidic separator element of FIG. 2. [Figure 7] It is a side view of another example of a plurality of flow channels that conform to the technology disclosed in this specification. [Figure 8] It is a side view of yet another example of a plurality of flow channels that conform to the technology disclosed in this specification. [Figure 9] It is a side view of yet another example of a plurality of flow channels that conform to the technology disclosed in this specification. [Figure 10] It is a schematic cross-sectional view of an exemplary separator system that conforms to the technology disclosed in this specification. [Figure 11] It is a schematic view of an exemplary embodiment that conforms to the technology disclosed in this specification.

Best Mode for Carrying Out the Invention

[0020] The figures are mainly created for clarity and, as a result, are not necessarily drawn to scale. Further, various structural / components including, but not limited to, fasteners, electrical components (wiring, cables, etc.) may be shown schematically or omitted from some or all of the drawings to more clearly show the aspects of the illustrated embodiments or when such structural / components are not necessary to understand the various exemplary embodiments described in this specification. However, the absence of illustration / description of such structural / components in a particular figure should not be construed as limiting the scope of the various embodiments in any way.

[0021] Exemplary Microfluidic Device Some embodiments of the technology disclosed herein relate to a separation assembly 100, a schematic diagram thereof shown in Figure 1. The separation assembly 100 generally includes a microfluidic separator element 110 and a permeate discharge layer 130 that abuts the microfluidic separator element 110.

[0022] A microfluidic separator element 110 is generally configured to receive a liquid flow having dispersed particles and separate the liquid flow into two liquid streams. The microfluidic separator element 110 generally has a substrate layer 120, an element inlet 112, a plurality of first element outlets 114, and a second element outlet 118. The element inlet 112 is in direct fluid communication with the first element outlets 114 and the second element outlets 118. The element inlet 112 is generally configured to receive the flow of fluid to be separated, i.e., the "feed" liquid stream. Each first element outlet 114 defines a fluid channel for the first liquid stream of the separated fluid (e.g., the "permeate" liquid stream) to flow out of the separator element 110. The second element outlet 118 defines a fluid channel for the second liquid stream of the separated fluid (e.g., the "retain" liquid stream) to flow out of the separator element.

[0023] As used herein, the term “particles” refers to the discrete amount of substance dispersed in a fluid. Non-limiting examples of substances that may form particles include soil, metals, cells, bubbles, fats, and water droplets. In one particular example, water droplets may be dispersed in a hydrocarbon fluid such as gasoline or diesel fuel to form an emulsion. In another example, bubbles may be dispersed in a hydraulic fluid. In yet another example, cells may be dispersed in an aqueous fluid. Cells may include eukaryotic cells. Examples of eukaryotic cells include mammalian cells, insect cells, plant cells, fungal cells, and bacterial cells. Further examples of eukaryotic cells include fish cells, crustacean cells, mollusk cells, and bird cells. In yet another example, particles may be pulp in orange juice, fat in milk, or impurities in beer or wine.

[0024] The microfluidic separator element 110 is configured to concentrate suspended particles in a feed liquid stream, and each element outlet 114, 116 can accept, for example, a liquid stream with a relatively high particle concentration ("particle-containing" liquid stream) or a liquid stream with a relatively low particle concentration ("particle-deficient" liquid stream). The targeted particles may be within a specific size range or have a minimum size. For example, particles with cross-sectional dimensions (such as diameter) in the range of 5 to 30 μm, 6 to 25 μm, or 10 to 20 μm may be targeted in particular by the microfluidic separator element 110. For non-spherical particles, for the purposes of the calculations herein, the particle diameter is considered to be the diameter of a volume-equivalent sphere. In some other examples, particles with cross-sectional dimensions of at least 5 μm, at least 10 μm, at least 15 μm, or at least 20 μm may be targeted by the microfluidic separator element 110. In some embodiments, the first element outlet 114 is configured to receive a particle-containing liquid stream, and the second element outlet 118 is configured to receive a particle-deficient liquid stream. In some other embodiments, the second element outlet 118 is configured to receive a particle-containing liquid stream, and the first element outlet 114 is configured to receive a particle-deficient liquid stream.

[0025] The microfluidic separator element 110 is defined as any type of microfluidic device configured to separate a fluid containing suspended particles into a particle-containing liquid stream and a particle-deficient liquid stream by a liquid flowing through one or more flow channels defined by the microfluidic device. Each flow channel has a configuration that facilitates the separation of the dispersed particle-containing liquid flowing within it into a particle-containing liquid stream and a particle-deficient liquid stream. In some embodiments, the microfluidic separator element 110 has multiple flow channels. In some other embodiments, the microfluidic separator element 110 has a single flow channel. In various embodiments, each flow channel has a height and width in the range of 20 to 1000 μm. In some embodiments, each of the flow channels is a microchannel. In some embodiments, the microfluidic separator element 110 is a hydrodynamic separator element, which is defined as a microfluidic device configured to concentrate particles in a liquid stream relying solely on the force due to the internal liquid flow.

[0026] Microfluidic separator elements 110 consistent with the technology disclosed herein generally have a substrate layer 120. The substrate layer 120 defines flow channels within it. The substrate layer 120 may be composed of various different materials and combinations of materials. In various embodiments, the substrate layer 120 is composed of an impermeable material, meaning that the substrate layer 120 does not allow liquid flow to pass through except through openings / paths defined in the substrate layer 120, such as flow channels, inlets, and outlets. In some embodiments, the substrate layer 120 may be made of a polymer. In some examples, the substrate layer 120 is polydimethylsiloxane (PDMS). The substrate layer 120 may be composed of polymers such as acrylic, polypropylene, polycarbonate, polyethylene, cyclic olefin copolymer (COC), and combinations thereof. In some embodiments, the substrate layer 120 may include glass. In some embodiments, the substrate layer 120 may include a non-reactive metal. In some embodiments, the substrate layer 120 may include one or more adhesive layers, such as pressure-sensitive adhesives. In some embodiments, the substrate layer 120 is composed of two or more materials.

[0027] It should be noted that in some embodiments, portions of the substrate layer 120 defining pathways for accommodating fluid flow, such as flow channels, may have material coatings to restrict particle adhesion to such pathways. Such coatings may include polyethylene glycol (PEG) chains or nonionic surfactants, such as those sold by BASF Corporation under the trademark name PLURONIC. Such coatings may be configured to restrict cell adhesion, particularly through liquid channels.

[0028] In some embodiments, the element inlet 112 of the microfluidic separator element 110 is defined toward a first side edge 102 of the substrate layer 120, and the second element outlet 118 is defined toward a second side edge 104 of the substrate layer 120. In such embodiments, the microfluidic separator element 110 defines a laterally extending outlet channel 116 between the element inlet 112 and the second element outlet 118. In some embodiments, the microfluidic separator element 110 defines a single first element outlet 114, but in other embodiments consistent with Figure 1, the microfluidic separator element 110 defines multiple first element outlets 114. Each first element outlet 114 may be laterally positioned between the element inlet 112 and the second element outlet 118. The outlet channel 116 generally extends laterally between the element inlet 112 and each of the first element outlets 114. Flow channel configurations are described in detail below. In this example, the second element outlet 118 facilitates the liquid flow out of the assembly 100, and the first element outlet 114 facilitates the liquid flow to the permeate discharge layer 130. In various embodiments, each first element outlet 114 is an axially defined opening that penetrates the substrate layer 120 and leads to the permeate discharge layer 130.

[0029] Permeate drainage layer The permeate discharge layer 130 is configured to receive fluid from the first element outlet 114. Therefore, the permeate discharge layer 130 is located downstream of the first element outlet 114. The permeate discharge layer 130 is in direct fluid communication with the first element outlet 114. The permeate discharge layer 130 is generally in contact with the substrate layer 120. The permeate discharge layer 130 generally extends laterally across the substrate layer 120. In some embodiments, the permeate discharge layer 130 has the same extent as the substrate layer 120.

[0030] The permeate discharge layer 130 defines a fluid volume 132 configured to receive liquid. In some embodiments, the fluid volume 132 is defined between the substrate layer 120 and the housing 134 of the permeate discharge layer 130. In some other embodiments, the housing 134 of the permeate discharge layer 130 encloses the fluid volume 132, and the housing 134 defines one or more openings that facilitate direct fluid communication between each first element outlet 114 and the fluid volume 132. In some embodiments, the fluid volume 132 is a void volume, i.e., empty space. In some such embodiments, the housing 134 is a liquid-impermeable material layer, and the fluid volume 132 is a fluid flow channel defined by the material layer between the housing 134 and the substrate layer 120. The fluid flow channel extends laterally through the material layer and across each of the first element outlets 114. The fluid flow channel is located downstream of a plurality of first element outlets 114. In various embodiments, the fluid flow channels forming the fluid volume 132 are microchannels. In various embodiments, the length of the fluid flow channels can be greater than or equal to the length across each of the first element outlets 114.

[0031] In some other embodiments, the fluid volume 132 is a porous material configured to receive liquid. In some embodiments, one or more spacers can be placed within the fluid volume between the substrate layer 120 and the housing 134 to maintain the size and shape of the fluid volume 132. In some embodiments, the fluid volume 132 is defined by a mesh material placed within the housing 134 of the permeate discharge layer 130, which defines a volume configured to receive liquid.

[0032] The permeate discharge layer 130 generally has permeate outlets 136 configured to facilitate the liquid flow out of the assembly 100. In some embodiments, the permeate discharge layer 130 has a plurality of permeate outlets 136, each configured to facilitate the liquid flow from the fluid volume 132 out of the assembly 100.

[0033] In some exemplary embodiments, two or more separator assemblies consistent with Figure 1 and the corresponding descriptions can be arranged in parallel, for example, the element inlet 112 of another separator assembly that substantially corresponds to the separator assembly 100 described above can be in fluid communication with the element inlet 112 of other separator assemblies in the group. In some such exemplary embodiments, the separator assemblies can be arranged in a stack, with the permeate discharge layer 130 in contact with a subsequent microfluidic separator element 110. The element inlet 112 of the subsequent microfluidic separator element 110 receives the liquid flow in parallel with the element inlets of one or more other separator elements in the stack. In such a configuration, the particle concentration (either particle-containing or particle-deficient) can be refined independently through each separator assembly 100.

[0034] In some alternative embodiments, one or more separator elements can be arranged in series, thereby allowing the particle concentration (either particle-containing or particle-deficient) from either the first element outlet 114 or the second element outlet 118 to be iteratively refined through each subsequent separation assembly 100. In some such exemplary embodiments, the separation assemblies are arranged in a stack, with the permeate discharge layer 130 in contact with a subsequent microfluidic separator element 110, and the element inlet 112 of the subsequent microfluidic separator element 110 receiving the liquid flow from the permeate layer outlet 136 or the second element outlet 118. In such a configuration, the particle concentration (either particle-containing or particle-deficient) from the relevant outlets 136 / 118 can be iteratively refined through each subsequent separation assembly 100. In some such examples, the permeate layer outlet 136 is in fluid communication with the element inlet 112 of another separation assembly. In some such alternatives, the second element outlet 118 is fluidly connected to the element inlet 112 of another separation assembly that substantially matches the separation assembly 100.

[0035] Note that the second element outlet 118 shown in Figure 1 extends axially from the permeate discharge layer 130, but the second element outlet 118 can extend in any direction, and in at least one example, the second element outlet 118 extends axially past the permeate discharge layer 130, bypassing it.

[0036] Exemplary microfluidic separator element Figure 2 is a perspective view of a portion of an exemplary substrate layer 120 of an exemplary microfluidic separator element 110, consistent with Figure 1, and Figure 3 is a detail view of Figure 2. More specifically, Figure 2 is a perspective view of the substrate layer 120 that roughly defines the flow channel of the microfluidic separator element 110. In various examples, the microfluidic separator element 110 has a cover layer 122 (Figure 1) sealed to the substrate layer 120, which seals the axial end of the flow channel defined by the substrate layer 120. Referring particularly to Figure 2, the cover layer 122 in Figure 1 is configured to seal the top surface of the flow channel (with respect to Figure 2). In Figure 2, the cover layer 122 is omitted for the visualization of the flow channel.

[0037] The microfluidic separator element 110 has a first microfluidic channel 140 that defines a channel inlet 142 (Figure 3) downstream of the element inlet 112 (Figure 1) and channel outlets including a first channel outlet 141 and a second channel outlet 143. The first microfluidic channel 140 is generally configured to receive liquid flow. The first channel outlet 141 is located upstream of the first element outlet 114 (Figure 1), and the second channel outlet 143 is located upstream of the second element outlet 118 (Figure 1). As described above, particles within a certain size range suspended in the liquid may be concentrated in one of the two channel outlets 141, 143 as a result of the liquid flowing from the channel inlet to the channel outlets 141, 143.

[0038] The microfluidic channels 140 can be formed on the substrate layer 120 by, for example, molding, photolithography, and 3D printing. In some examples, the microfluidic channels 140 are formed on the substrate layer 120 by plastic injection molding or embossing. Other methods can also be used to form the microfluidic channels 140.

[0039] The first microfluidic channel 140 has a channel length L from the channel inlet 142 to the first channel outlet 141. D The length of the first microfluidic channel 140 is generally curved, defining an arc. Generally, the length of the first microfluidic channel 140 defines an arc of 270° or less, and in some embodiments, 200° or less. In various examples, such as those consistent with Figure 3, the length of the first microfluidic channel 140 defines an arc of approximately 180° around the central axis x. The length of the first microfluidic channel 140 defines an arc with an inner radius R around the central axis x. C It can be curved to define the axis. Therefore, the length of the first microfluidic channel 140 can extend circumferentially around the central axis x. In this example, the inner radius R C While is substantially constant along the entire length of the first microfluidic channel 140, in some other examples the inner radius R C This can change. In this example, the length of the first microfluidic channel 140 extends approximately 180° around the central axis x.

[0040] In this example, the first microfluidic channel 140 defines a single curve, but in some other examples, the microfluidic channel 140 may define two or more connected curves. For example, the first microfluidic channel 140 may define two curves in opposite directions. One example of the first microfluidic channel 140 defining two curves in opposite directions could be an "S-shape," in which the first part of the first microfluidic channel 140 curves in the first direction, and the second part curves in the second opposite direction. Examples of such configurations are described in detail below.

[0041] In this example, the first microfluidic channel 140 has a roughly rectangular cross-section along the channel length, as shown in Figure 4. The cross-section of the first microfluidic channel 140 is roughly perpendicular to the direction of the liquid flow through the first microfluidic channel 140. The first microfluidic channel 140 has a height (h) and a width (w), as shown in Figure 4. The first microfluidic channel 140 has an inner wall 144 and an outer wall 146, where the inner wall 144 is the wall defining the inner radius of curvature Rc and the outer wall 146 defines the outer radius. The width w of the first microfluidic channel 140 is the distance between the inner wall 144 and the outer wall 146. The first microfluidic channel 140 also has a hydraulic diameter (D H ) has. To calculate the hydraulic diameter of a microfluidic channel with a rectangular cross-section, the following formula is used:

number

[0042] The first microfluidic channel 140 is configured to receive a liquid having a Reynolds number (Re) within the liquid channel. The liquid flow in the curved channel is represented by two dimensionless numbers: the Reynolds number and the Dean number. The Reynolds number represents the ratio of inertial force to viscous force and is defined as follows:

number

[0043] Here, ρ is the fluid density, U is the mean fluid velocity, and μ is the fluid's kinematic viscosity. In a hydrodynamic separator, the Reynolds number is typically small (<1000), so the flow profile is laminar. In various embodiments, the system is configured so that the Dean number (De) is between 5 and 25. In various embodiments, the system is configured so that the Dean number is between 5 and 20. The Dean number describes the behavior of the fluid in a curved pipe and takes into account the inertial, centripetal, and viscous forces acting on the fluid. The Dean number is defined as follows:

number

[0044] The microfluidic separator element 110 is generally configured to concentrate particles in the first microfluidic channel 140. In various embodiments, the separator element 110 is configured to concentrate particles having a diameter greater than 8% of the hydraulic diameter of the first microfluidic channel 140. When the Dean number is in the range of 5 to 25, particles having a diameter greater than 8% of the channel hydraulic diameter are generally concentrated toward the inner wall. The hydrodynamic separator is generally configured to concentrate particles having a diameter that is 50% or less of the channel height. In various embodiments, the hydrodynamic separator consistent with the technology disclosed herein is configured to concentrate particles having a concentration up to three times greater than the liquid in the first microfluidic channel 140.

[0045] Exemplary microfluidic channels In various embodiments consistent with the technology disclosed herein, the microfluidic separator element 110 has a plurality of microfluidic channels 150, including a first microfluidic channel 140. Each microfluidic channel of the plurality of microfluidic channels 150 is consistent with the description of the first microfluidic channel 140 herein. Thus, each microfluidic channel of the plurality of microfluidic channels 150 defines a channel inlet 152 downstream of the element inlet 112 (Figure 1), a first channel outlet 151 upstream of the first element outlet 114, and a second channel outlet 153 upstream of the second element outlet 118. Similarly, in various embodiments, each microfluidic channel of the plurality of microfluidic channels 150 has an inner wall and an outer wall, and each microfluidic channel is configured to concentrate particles in the liquid stream toward the inner wall. The plurality of microfluidic channels 150 are arranged to operate substantially in parallel with respect to the liquid flow through the microfluidic separator element 110.

[0046] Multiple microfluidic channels 150 are positioned relatively close together to relatively increase the liquid flow capacity that the microfluidic separator element 110 can accommodate. In various embodiments, the substrate layer 120 defines at least 4, at least 6, or at least 10 microfluidic channels.

[0047] In various embodiments, the multiple microfluidic channels 150 are arranged in a pattern in the transverse direction across the substrate layer 120. In some embodiments, this pattern is regular. In some embodiments, including those depicted in Figure 2, each of the multiple microfluidic channels 150 is nested with adjacent microfluidic channels. This means that each of the multiple microfluidic channels 150 defines at least one arc along its length, defining a concave region between the channel inlet 152 and the channel outlets 151, 153, and this concave region overlaps with the concave region of the adjacent channel. An example of this is shown in Figure 5, a side view of some of the multiple microfluidic channels 150 in the substrate layer 120, consistent with Figures 2 and 3. The first microfluidic channel 140 has a concave region 148 defined between its inlet 142 and its first channel outlet 141 (and second channel outlet 143), which is received by a concave region 168 defined between the channel inlet 162 and the first channel outlet 161 of the second microfluidic channel 160, or by a 16-oncavee region defined between the channel inlet 162 and the second channel outlet 163. Each of the multiple microfluidic channels 150 is nested with an adjacent microfluidic channel.

[0048] In various embodiments, each microfluidic channel 150 is laterally offset from adjacent microfluidic channels 150 across the substrate layer 120. This offset can define a specific offset distance D1 between corresponding positions along adjacent microfluidic channels 150. For example, the channel inlet 142 of the first microfluidic channel 140 can be spaced by an offset distance D1 from the channel inlet 162 of the second microfluidic channel 160. The offset distance D1 is not particularly limited, but is generally smaller than the radius of curvature of the curvature defined by the microfluidic channel. In some embodiments, D1 may be 20 mm or less, 18 mm or less, 16 mm or less, 14 mm or less, or 12 mm or less. In some embodiments, D1 is constant, which means that the lateral offset between adjacent microfluidic channels 150 is substantially equal.

[0049] Each microfluidic channel in a plurality of microfluidic channels 150 can be positioned within a specific lateral distance D2 from an adjacent microfluidic channel. This means that a first position along the length of a particular microfluidic channel 150 is within a specific lateral distance D2 from a second position along the length of an adjacent microfluidic channel, where the second position does not necessarily correspond to the first position. For example, as shown in Figure 5, the lateral distance D2 between the second channel outlet 163 and the first microfluidic channel 140 is smaller than the offset distance D1 between the first microfluidic channel 140 and the second microfluidic channel 160. In some embodiments, the lateral distance D2 of a microfluidic channel is within 12 mm or 10 mm from an adjacent microfluidic channel. Each microfluidic channel in a plurality of microfluidic channels 150 can be positioned within 5 mm from an adjacent microfluidic channel. Each microfluidic channel in a plurality of microfluidic channels 150 can be positioned within 3 mm from an adjacent microfluidic channel. Each microfluidic channel in a plurality of microfluidic channels 150 can be positioned within 2 mm from an adjacent microfluidic channel.

[0050] Returning to Figures 2 and 3, the substrate layer 120 defines a layer inlet 124 (Figure 2), a plurality of first layer outlets 121 (most clearly visible in Figure 3), and a second layer outlet 123 (Figure 2). The layer inlet 124 is generally configured to receive a liquid flow from outside the substrate layer 120. The layer inlet 124 is located upstream of each of the channel inlets 152. The inlet channel 126 fluidically couples the layer inlet 124 to each of the channel inlets 152, including the channel inlet 142 of the first microfluidic channel 140. Each of the channel inlets 152 is arranged continuously along the length of the inlet channel 126. Thus, the fluid is configured to flow from the element inlet 112 (Figure 1), through the layer inlet 124, along the inlet channel 126, and to the channel inlets 152. It should be noted that in some embodiments, the cross-sectional flow area defined by the inlet channel 126 may tapere from the channel inlet 142 of the first microfluidic channel 140 to the channel inlet of the last microfluidic channel fluidically coupled to the inlet channel 126. The tapering of the cross-sectional flow area of ​​the inlet channel 126 can be configured to maintain a relatively constant average liquid flow velocity along the length of the inlet channel 126, even though the liquid volume gradually decreases along the length of the inlet channel 126 to each of the microfluidic channels 150. In some other embodiments, the cross-sectional flow area of ​​the inlet channel 126 is kept constant along its length.

[0051] In an example consistent with Figure 1, the layer inlet 124 of the substrate layer 120 receives the liquid flow from the element inlet 112, where the element inlet 112 is defined by the cover layer 122. In some other embodiments, the layer inlet is an element inlet. For example, this is the case in which the liquid flow path penetrates laterally through the axial surface 125 of the substrate layer 120 to the inlet flow path 126.

[0052] Each first layer outlet 121 defines a fluid flow path exiting the substrate layer 120. Each first channel outlet 151 is located upstream of the first layer outlet 121. Each of the first channel outlets 151, including the first channel outlet 141 of the first microfluidic channel 140, is located upstream of the first element outlet 114, schematically shown in Figure 1 and a detailed specific example shown in Figure 6. Figure 6 is a cross-sectional view of the substrate layer 120 through each of the first channel outlets 151. In this example, each first layer outlet 121 penetrates the substrate layer 120 axially and fluidly couples the corresponding first channel outlet 151 to the outside of the substrate layer 120. The first layer outlet 121 can have the same fluid flow path as the first element outlet 114. In various embodiments, such as those consistent with the schematic diagram in Figure 1, each first element outlet 114 fluidly couples the corresponding first channel outlet 151 to the permeate discharge layer 130.

[0053] The second layer outlet 123 defines the fluid channel exiting the substrate layer 120. The microfluidic separator element 110 has an outlet channel 116 (Figures 2 and 3) that fluid-communicates with the element inlet 112 and the second element outlet 118, where an exemplary element inlet 112 and an exemplary second element outlet 118 are schematically shown in Figure 1. More specifically, the outlet channel 116 extends between the element inlet 112 and the second element outlet 118. The outlet channel 116 is located downstream of the element inlet 112. The outlet channel 116 is located downstream of each of the second channel outlets 153. The outlet channel 116 is located upstream of the second element outlet 118. Therefore, a portion of the liquid flowing through each of the multiple microfluidic channels 150 (e.g., a particle-containing or particle-deficient liquid flow) passes through the corresponding second channel outlet 153, along the outlet flow path 116, through the second layer outlet 123, and is discharged out of the microfluidic separator element 110 from the second element outlet 118.

[0054] The examples shown in Figures 2, 3, 5, and 6 include multiple microfluidic channels 150 operating in parallel, but in some embodiments, the microfluidic separator element 110 has a single microfluidic channel. In some embodiments, the microfluidic separator element 110 has one or more microfluidic channels with alternative shapes, such as having a lateral profile different from the arcs shown in the aforementioned figures.

[0055] Figure 7 is a side view of an exemplary substrate layer 220 of a microfluidic separator element 110 (such as the example in Figure 1) having a plurality of microfluidic channels 250 consistent with the technology disclosed herein. Each of the plurality of microfluidic channels 250 is substantially consistent with the above description (incorporated by reference herein) of the microfluidic separator element and microfluidic channels, except where such description or example shown in Figure 7 is inconsistent.

[0056] The hydrodynamic separator element has a substrate layer 220 defining a layer inlet 224, a plurality of first layer outlets 221, and a second layer outlet 223. The substrate layer 220 is generally impermeable. The substrate layer 220 defines an outlet channel 216 upstream of the second layer outlet 223. The substrate layer 220 defines a plurality of curved microfluidic channels 250 arranged to operate in parallel. In various embodiments, the technology includes at least six microfluidic channels 250 within the substrate layer 220. Each microfluidic channel 250 defines a channel inlet 252 downstream of the layer inlet 224. In this example, the inlet channel 226 fluidically couples the layer inlet 224 and the channel inlet 252, which may be consistent with other inlet channel descriptions in this specification. Each microfluidic channel 250 defines a first channel outlet 251 upstream of the first layer outlet 221 of the plurality of first layer outlets. Each microfluidic channel 250 has a second channel outlet 253 upstream of the outlet channel 216.

[0057] When a separator element having a substrate layer consistent with this example is incorporated into an assembly consistent with Figure 1, each channel inlet 252 is configured to be located downstream of the element inlet 112 (Figure 1), the first channel outlet 251 is configured to be located upstream of the first element outlet 114 (Figure 1), and the second channel outlet 253 is configured to be located upstream of the second element outlet 118 (Figure 1). The multiple microfluidic channels 250 are generally arranged to operate in parallel with respect to the liquid flow through the microfluidic separator element. As previously mentioned, each of the multiple microfluidic channels 250 has an inner wall and an outer wall (consistent with Figure 4), and each microfluidic channel 250 can be configured to concentrate particles in the liquid stream toward its inner wall. The particles may be in the range of 10 to 20 micrometers. In some examples, the particles are eukaryotic cells such as mammalian cells or insect cells, or other cells as described above.

[0058] Similar to the example described above, each of the multiple microfluidic channels 250 is curved. In particular, the length of each microfluidic channel is curved between the channel inlet 252 and the channel outlets 251, 253. In this example, each microfluidic channel 250 defines two curves in opposite directions. That is, each microfluidic channel 250 has a first length 254 that curves outward (or curves toward the first transverse direction) and a second length 256 that curves inward (or curves toward the second transverse direction opposite to the first transverse direction). Other curvature shapes are also possible.

[0059] Similar to the example described above, in this example as well, the length of each microfluidic channel defines an arc of 270° or less or 200° or less. As shown in the figure, in this design, each of the multiple microfluidic channels 250 is nested with adjacent microfluidic channels, which advantageously maximizes the amount of liquid flow that the substrate layer can accommodate. In particular, as shown in Figure 7, each microfluidic channel 250 defines at least one arc along its length, defining a concave region 258 between the channel inlet 252 and the channel outlets 251, 253, and this concave region 258 overlaps with the concave region 258 of the adjacent microfluidic channel. In this example, each microfluidic channel is located within 12 mm, 10 mm, 5 mm, 3 mm, or 2 mm of an adjacent microfluidic channel. In some embodiments, each microfluidic channel is located within 12 mm or 10 mm of an adjacent microfluidic channel along at least 50% of its length. In some embodiments, each microfluidic channel is positioned within 5 mm of an adjacent microfluidic channel along at least 50% of its length. In some embodiments, each microfluidic channel is positioned within 3 mm of an adjacent microfluidic channel along at least 50% of its length. In some embodiments, each microfluidic channel is positioned within 2 mm of an adjacent microfluidic channel along at least 50% of its length.

[0060] Figure 8 is a side view of yet another exemplary substrate layer 620 of a microfluidic separator element 110 (such as the example in Figure 1) having a plurality of microfluidic channels 650 consistent with the technology disclosed herein. Each of the plurality of microfluidic channels 650 is generally consistent with the above description (incorporated by reference herein) of the microfluidic separator element and microfluidic channels, unless otherwise contradicted by this description or the example depicted in Figure 8.

[0061] The hydrodynamic separator element has a substrate layer 620 defining a layer inlet 624, a plurality of first layer outlets 621, and a second layer outlet 623. The substrate layer 620 is generally impermeable. In this example, the substrate layer 620 has a circular lateral profile, but the substrate layer 620 may have an alternative lateral shape. Unlike the above example, in this example, there are no independent inlet channels because the layer inlet 624 is directly fluidically coupled to each of the channel inlets 652. In this example, the layer inlet 624 is defined by an opening in the substrate layer 620 located at the center of all the channel inlets 652 of the plurality of microfluidic channels 650. In some other embodiments, the layer inlet 624 may be a discrete opening, and the substrate may define inlet channels that sequentially fluidically couple the layer inlet 624 to each channel inlet 652.

[0062] The substrate layer 620 defines an outlet channel 616 upstream of the second layer outlet 623. In this example, the lateral profile of the outlet channel 616 is circular. The length of the outlet channel 616 is radially positioned between the plurality of microfluidic channels 650 and the outer boundary 629 of the substrate layer 620. The substrate layer 620 defines a plurality of curved microfluidic channels 650 arranged to operate in parallel. In various embodiments, the technology includes at least six or at least ten microfluidic channels 650 within the substrate layer 620. Each microfluidic channel 650 defines a channel inlet 652 downstream of the layer inlet 624. Each microfluidic channel 650 defines a first channel outlet 651 upstream of the first layer outlet 621 of the plurality of first layer outlets. Each microfluidic channel 650 has a second channel outlet 653 upstream of the outlet channel 616. In some alternative embodiments, the outlet channel 616 can be omitted if the layer outlet is the outer peripheral boundary 629 of the substrate 620 and the second channel outlet 653 extends to the outer peripheral boundary 629.

[0063] As described above with respect to Figure 7, the channel inlet 652 is configured to be located downstream of the element inlet 112 (Figure 1), the first channel outlet 651 is configured to be located upstream of the first element outlet 114 (Figure 1), and the second channel outlet 653 is configured to be located upstream of the second element outlet 118 (Figure 1). The multiple microfluidic channels 650 are generally arranged to operate in parallel with respect to the liquid flow through the microfluidic separator element. As previously mentioned, each of the multiple microfluidic channels 650 has an inner wall and an outer wall (consistent with Figure 4), and each microfluidic channel 650 can be configured to concentrate particles in the liquid stream toward its inner wall. The particles can be in the range of 10 to 20 micrometers. In some examples, the particles are eukaryotic cells such as mammalian cells or insect cells.

[0064] Similar to the previously mentioned example, each of the multiple microfluidic channels 650 is curved. In particular, the length of each microfluidic channel is curved between the channel inlet 652 and the channel outlets 651, 653. In this example, each microfluidic channel 650 defines a single curve, but more complex curves, such as those depicted in Figure 7, are also possible. Unlike some other examples, each microfluidic channel 650 is curved in different lateral directions. In particular, each microfluidic channel 650 extends radially outward from the layer inlet 624 toward the outer boundary 629 of the substrate layer 620. The channel inlets 652 of the microfluidic channels 650 are spaced circumferentially around the central area of ​​the substrate layer 620 (layer inlet 624 in this example). The channel outlets 651, 653 are spaced circumferentially around the outer area of ​​the substrate layer 620. Each of the multiple microfluidic channels 650 can define the same curve, and each arc is angularly offset from the adjacent microfluidic channels 650.

[0065] Similar to the previously mentioned example, in this example, the length of each microfluidic channel defines an arc of 270° or less or 200° or less. As shown in the figure, in this design, each of the multiple microfluidic channels 650 is nested with adjacent microfluidic channels, which advantageously maximizes the amount of liquid flow that the substrate layer can accommodate. In particular, as shown in Figure 8, each microfluidic channel 650 defines at least one arc along its length, defining a concave region 658 between the channel inlet 652 and the channel outlets 651, 653, and this concave region 658 overlaps with the concave region 658 of the adjacent microfluidic channel. In this example, each microfluidic channel is located within 12 mm, 10 mm, 5 mm, or 3 mm of an adjacent microfluidic channel. In some embodiments, each microfluidic channel is located within 12 mm, 10 mm, 5 mm, or 3 mm of an adjacent microfluidic channel along at least 50% of its length.

[0066] Figure 9 is a side view of yet another exemplary substrate layer 720 of a microfluidic separator element 110 (such as the example in Figure 1) having a plurality of microfluidic channels 750 consistent with the technology disclosed herein. Each of the plurality of microfluidic channels 750 is substantially consistent with the above description (incorporated by reference herein) of the microfluidic separator element and microfluidic channels, except where otherwise contradicts the description or example depicted in Figure 9.

[0067] The hydrodynamic separator element has a substrate layer 720 defining a layer inlet 724, a plurality of first layer outlets 721, and second layer outlets 723. Unlike the previous example, here the substrate layer 720 defines two second layer outlets 723. The substrate layer 720 defines an outlet channel 716 upstream of each second layer outlet 723. The substrate layer 720 defines a plurality of curved microfluidic channels 750 arranged to operate in parallel. In various embodiments, the technology includes at least six microfluidic channels 750 within the substrate layer 720. Each microfluidic channel 750 defines a channel inlet 752 downstream of the layer inlet 724. In this example, an inlet channel 726 fluidly couples the layer inlet 724 and the channel inlet 752. The inlet channel 726 may have a cross-sectional flow area that tapers inward along its length. Each microfluidic channel 750 defines a first channel outlet 751 upstream of a first layer outlet 721 among a plurality of first layer outlets. Each microfluidic channel 750 has a second channel outlet 753 upstream of the outlet channel 716.

[0068] When a separator element having a substrate layer consistent with this example is incorporated into an assembly consistent with Figure 1, each channel inlet 752 is configured to be located downstream of the element inlet 112 (Figure 1), the first channel outlet 751 is configured to be located upstream of the first element outlet 114 (Figure 1), and each second channel outlet 753 is configured to be located upstream of the second element outlet 118 (Figure 1). The multiple microfluidic channels 750 are generally arranged to operate in parallel with respect to the liquid flow through the microfluidic separator element. As previously mentioned, each of the multiple microfluidic channels 750 has an inner wall and an outer wall (consistent with Figure 4), and each microfluidic channel 750 can be configured to concentrate particles in the liquid stream toward its inner wall. The particles can be in the range of 10 to 20 microns. In some examples, the particles are eukaryotic cells, such as those described above.

[0069] Similar to the example described above, each of the multiple microfluidic channels 750 is curved. In particular, the length of each microfluidic channel is curved between the channel inlet 752 and the channel outlets 751, 753. Each microfluidic channel 750 has a first laterally curved length 754. As described above, other curvature shapes are also possible.

[0070] In this example, the multiple microfluidic channels 750 defined by the substrate 720 include a first set of microfluidic channels 750a and a second set of microfluidic channels 750b. The first set of microfluidic channels 750a has a channel inlet 752 on the opposite side of the channel inlet 752 of the second set of microfluidic channels 750b with respect to the inlet channel 726. In this example, the first set of microfluidic channels 750a is curved laterally in the same direction as the second set of microfluidic channels 750b. In some other examples, the first set of microfluidic channels 750a is curved laterally in a different direction than the second set of microfluidic channels 750b. For example, the first set of microfluidic channels 750a can be curved laterally in the opposite direction to the second set of microfluidic channels 750b. In this example, the first set of microfluidic channels 750a has a nested configuration, and the second set of microfluidic channels 750b also has a nested configuration. However, the first set of microfluidic channels 750a is not nested with the second set of microfluidic channels 750b.

[0071] Similar to the example described above, in this example as well, the length of each microfluidic channel defines an arc of 270° or less or 200° or less. As shown in the figure, in this design, each of the multiple microfluidic channels 750 is nested with the adjacent channel, which advantageously maximizes the amount of liquid flow that the substrate layer can accommodate. In particular, as shown in Figure 7, each microfluidic channel 750 defines at least one arc along its length, and the arc defines a concave region 758 between the channel inlet 752 and the channel outlets 751, 753, and this concave region 758 overlaps with the concave region 758 of the adjacent microfluidic channel. In this example, each microfluidic channel is within 12 mm, 10 mm, 5 mm, or 3 mm of the adjacent microfluidic channel along at least 50% of its length.

[0072] Exemplary Embodiments Exemplary microfluidic separator elements and separation assemblies consistent with the technology disclosed herein can be advantageously incorporated into a variety of different systems. An example system, 301, is schematically depicted in Figure 10, and this system can incorporate one or more separator elements 310, for example, consistent with Figure 1. Each separator element 310 can incorporate a substrate layer consistent with the substrate layers discussed elsewhere in this specification, particularly with reference to any of Figures 2-9. The corresponding above descriptions relating to separator elements and related components are incorporated herein by reference.

[0073] In this example, the system 301 disclosed herein may correspond to a filtration cassette in various embodiments. In this exemplary system, at least one separator element 310 is positioned in series with the tangential flow filter 370. The separator element 310 is positioned upstream of the tangential flow filter 370. By positioning the separator element 310 upstream and in series with the tangential flow filter 370, the fouling of the filter medium 378 within the tangential flow filter 370 can be delayed, thereby advantageously extending the life of the tangential flow filter 370. In this example, the separator element 310 functions as a pre-filter for the tangential flow filter 370.

[0074] The separator element 310 can be a hydrodynamic separator element in various embodiments. The separator element 310 has an element inlet 312, a plurality of first element outlets 316, and a second element outlet 318. Although not shown here, the separator element 310 may have a plurality of curved microfluidic channels between the element inlet 312 and the first element outlets 316. Each element inlet 312 is in direct fluid communication with the corresponding layer inlet 324 and is located upstream of it. The curved microfluidic channels are consistent with the curved microfluidic channels discussed elsewhere in this specification. For example, each curved microfluidic channel may have an inner wall 144 and an outer wall 146 (Figure 4). In various embodiments, the separator element 310 is configured to concentrate particles along the inner wall. In such embodiments, the pressure loss and liquid flow velocity required for particle separation may be reduced compared to systems that concentrate particles along the outer wall, which may favorably maintain cell viability when the separator element 310 is configured to concentrate particles such as cells.

[0075] The tangential flow filter 370 may correspond to various tangential flow filters known in the art. Generally, the tangential flow filter 370 has a feed inlet 372, a retaining liquid outlet 376, and a permeate outlet 374. The feed inlet 372 is located downstream of the first element outlet 316. The filter medium 378 is placed between the feed inlet 372 and the permeate outlet 374. As is generally known in the art, a liquid containing suspended particles flows across the surface of the filter medium 378. The permeate is configured to pass through the filter medium 378 and reach the permeate outlet 374. The retaining liquid is configured to flow along the surface of the filter medium 378 to the retaining liquid outlet 376, rather than passing through the filter medium 378.

[0076] Consistent with the examples discussed elsewhere in this specification, the separator element 310 may have a substrate layer defining a layer inlet, a plurality of first layer outlets, and a second layer outlet. The layer inlet is located downstream of the element inlet 312. Each first layer outlet is located upstream of the first element outlet 316. The second layer outlet is located upstream of the second element outlet 318. In some embodiments, each substrate layer may define a single microfluidic channel. In other embodiments, the substrate layer of each separator element 310 may define a plurality of curved microfluidic channels extending between the element inlet 312 and each element outlet 316, 318. The plurality of curved microfluidic channels may extend between the layer inlet and the first layer outlet of the plurality of first layer outlets of the substrate layer of the separator element 310, as described above. The plurality of curved microfluidic channels may be consistent with the descriptions and figures elsewhere in this specification.

[0077] In various embodiments, the system has multiple separator elements 310. The separator elements 310 are stacked with the tangential flow filter 370. Thus, each substrate layer of the separator elements 310 is also stacked. In various embodiments, the multiple separator elements 310 are stacked with the tangential flow filter 370. The multiple separator elements 310 are arranged in parallel in various embodiments. In some examples, such as the example corresponding to Figure 10, each first element outlet 316 of each separator element 310 is located upstream of the permeate layer outlet 336 and is fluidically coupled. The permeate layer outlet 336 of each separator element 310 is in fluid communication. Each permeate layer outlet 336 is located upstream of the feed inlet 372 of the tangential flow filter 370 and is fluidically coupled. The multiple separator elements 310 are collectively arranged in series with the tangential flow filter 370.

[0078] In some examples, each separator element 310 is a component of a separation assembly 300. Each separation assembly 300 may have a permeate discharge layer 330 downstream of the plurality of first layer outlets 321 and plurality of first element outlets 316 of the separator element 310. The permeate discharge layer 330 may be in contact with a substrate layer as described elsewhere in this specification. The permeate discharge layer 330 may extend laterally into the corresponding substrate layer of an adjacent separator element 310. The permeate discharge layer 330 is consistent with the figures and descriptions elsewhere in this specification.

[0079] In various embodiments, each separation assembly 300 is arranged in parallel with other separator assemblies 300 within the system 301. In various embodiments, multiple separator assemblies 300 are stacked with a tangential flow filter 370. Multiple separator assemblies 300 are arranged in series with a tangential flow filter 370. In some examples, such as those corresponding to Figure 10, a permeate discharge layer 330 is located upstream of the feed inlet 372 of the tangential flow filter 370 and has a permeate layer outlet 336 that is fluidically coupled thereto.

[0080] In this example, three exemplary separator assemblies 300 are arranged in a stack, but it will be understood that a separator system consistent with that disclosed herein could include hundreds of separator assemblies 300. In some embodiments, the separator systems disclosed herein arrange 10 to 30, 20 to 60, 50 to 100, or 100 to 200 separator assemblies 300 in parallel. It will be understood that the height of each separator assembly 300 may range from 1 mm to 10 mm or 2 mm to 5 mm in some embodiments.

[0081] In this example, each second element outlet 318 of each separator element 310 is in fluid communication with the second element outlet 318 of other separator elements 310 in the system 301. In particular, the outlet flow path 302 is defined by each of the separator elements 310. Each second element outlet 318 is in direct fluid communication with the outlet flow path 302. Furthermore, in this example, the retaining fluid outlet 376 of the tangential flow filter 370 is also in direct fluid communication with the outlet flow path 302.

[0082] In various embodiments, each isolation assembly 300 within the system 301 has a lateral profile having the same spread as the lateral profile of the tangential flow filter 370. In various embodiments, each isolation assembly 300 has a configuration that allows it to be incorporated into a tangential flow filter cassette assembly.

[0083] In some examples, system 301 is configured to separate particles with a diameter of 10-20 microns from a liquid stream. In various examples, system 301 is configured to separate eukaryotic cells (e.g., the exemplary eukaryotic cells described above) from a liquid stream. In some such exemplary embodiments, system 301 is a component of the cell retention device of a perfusion bioreactor. Perfusion bioreactors can generally be used in the production of biopharmaceuticals. A schematic diagram of such a perfusion bioreactor is schematically shown in Figure 11, which is described below.

[0084] A perfusion bioreactor 500 typically comprises a cell culture tank 510, a microfluidic separator element 410, and a tangential flow filter 470. The microfluidic separator element 410 is a component of a separation assembly 400, which is a component of a separator system 401, such as the one described above with reference to Figure 10. The tangential flow filter 470 is a component of the separator system 401, also consistent with the description in Figure 10. It will be understood that in some examples the tangential flow filter 470 and the microfluidic separator element 410 may be discrete components, while in other examples the tangential flow filter 470 and the microfluidic separator element 410 may be integrated within a single component assembly such as a cassette.

[0085] The cell culture tank 510 is generally configured to contain a liquid medium and cells dispersed within the liquid medium. The cell culture tank is generally configured to promote cell culture. The perfusion bioreactor 500 is generally configured to circulate the liquid medium within the system to maintain favorable culture conditions in the cell culture tank 510.

[0086] The separator system 401 generally has a system inlet 402 configured to receive a liquid stream containing particles (such as a liquid stream containing cells). The system inlet 402 is in direct fluid communication with each element inlet 412 of each separator element 400. In some embodiments, the system inlet 402 may be the element inlet 412 of the separator element 400 detailed above. In this example, the system inlet 402 is the inlet of the upstream separator element 400 of the multiple separator elements 400. The liquid stream is received from a cell culture tank 510 in some embodiments and from a different source in other embodiments. In various embodiments, a pre-filter element 540 may be located upstream of the system inlet 402. The pre-filter element 540 is a component of the separator system 401 and is coupled to the separator element 400 upstream of the system inlet 402. In some other embodiments, the pre-filter element 540 is a separate component from the separator element 400 and is in fluid communication with the liquid flow path located upstream of the system inlet 402. The pre-filtration element 540 may be configured to capture relatively large particles, such as cell aggregates, which could potentially block the liquid flow path of the separator element 400.

[0087] The liquid stream can flow through each separator element 410 in parallel. Thus, the element inlet 412 is positioned in parallel with the system inlet 402. Within each separator element 410, as described above, the liquid stream can flow through multiple curved microfluidic channels in parallel. Each microfluidic channel separates the liquid stream into a particle-containing liquid stream and a particle-deficient liquid stream. The particle-deficient portion of the liquid stream can pass through each first channel outlet and each first element outlet 416 as described above. Such particle-deficient portions of the liquid stream exit each first element outlet 416 and enter the feed inlet 472 of the adjacent permeate discharge layer 330. The particle-deficient portions of the liquid stream are configured to flow through the feed inlet 472 of the tangential flow filter 470, thereby further separating the particle-deficient portions of the liquid stream into a particle-containing liquid stream and a particle-deficient liquid stream. The particle-deficient portion of the liquid stream is configured to flow through the permeate outlet 474 of the tangential flow filter 470 and along the channel 520 to an external system for processing or disposal.

[0088] The particle-containing portion of the liquid stream can exit, for example, from the respective second element outlets 418 of each separator element 410. The particle-containing liquid stream is configured to pass through the second outlets 418 of the corresponding separator element 410 and reach an outlet flow line 404, which allows the liquid stream to exit the separator system 401. Similarly, the retaining fluid stream can exit the tangential flow filter 470 via the retaining fluid outlet 476. The retaining fluid outlet 476 is also fluid-communicated with the outlet flow line 404. In some such exemplary embodiments, the cell culture tank 510 is positioned downstream of the tangential flow filter 470 and is fluid-communicated with it. The cell culture tank 510 may also be positioned downstream of each of the separator elements 410 and is fluid-communicated with it. The cell culture tank 510 is generally positioned downstream of the separator system 401 and is fluid-communicated with it. The cell culture tank 510 generally has an inlet 514 that is in fluid communication with the outlet flow line 404 of the separator system 401.

[0089] As described above, in some embodiments, the cell culture tank 510 may be located upstream of the separator system 401. In such embodiments, the cell culture tank 510 has an outlet 512 that is in fluid communication with the inlet 402 of the separator assembly 401.

[0090] In various embodiments, the liquid pump 530 is fluidically coupled to the separator system 401 and the cell culture tank 510 to facilitate the liquid flow through the system 500.

[0091] Exemplary aspects Embodiment 1. A microfluidic separation element comprising a substrate layer, wherein the microfluidic separation element comprises a microfluidic separation element defining an element inlet, a plurality of first element outlets defined by the substrate layer, and a second element outlet, and a permeate discharge layer in contact with the substrate layer, the permeate discharge layer located downstream of the plurality of first element outlets, wherein the separation assembly comprises a microfluidic separation element defining an element inlet, a plurality of first element outlets defined by the substrate layer, and a permeate discharge layer located downstream of the plurality of first element outlets.

[0092] Embodiment 2. The separation assembly according to any one of Embodiments 1 and 3 to 21, wherein the permeate discharge layer extends laterally across the substrate layer.

[0093] Embodiment 3. The separation assembly according to any one of embodiments 1 to 2 and 4 to 21, wherein the separation assembly is a component of the cell retention device of a perfusion bioreactor.

[0094] Embodiment 4. The separation assembly according to any one of embodiments 1 to 3 and 5 to 21, wherein the microfluidic separation element is a hydrodynamic separator element.

[0095] Embodiment 5. The separation assembly according to any one of embodiments 1 to 4 and 6 to 21, wherein the permeate discharge layer is defined by a mesh material.

[0096] Embodiment 6. The separation assembly according to any one of embodiments 1 to 5 and 7 to 21, wherein the permeate discharge layer is a material layer defining microchannels downstream of a plurality of first layer outlets.

[0097] Embodiment 7. The separation assembly according to any one of embodiments 1 to 6 and 8 to 21, further comprising a first microfluidic channel, the first microfluidic channel defining a channel inlet downstream of an element inlet, and defining a channel outlet having a first channel outlet upstream of a first element outlet and a second channel outlet upstream of a second element outlet among a plurality of first channel outlets.

[0098] Embodiment 8. The separation assembly according to any one of embodiments 1 to 7 and 9 to 21, wherein the first microfluidic channel is curved.

[0099] Embodiment 9. A separation assembly according to any one of embodiments 1 to 8 and 10 to 21, further comprising a plurality of microfluidic channels including a first microfluidic channel, wherein each microfluidic channel defines a channel inlet downstream of an element inlet, a first channel outlet upstream of a first element outlet among a plurality of first element outlets, and a second channel outlet upstream of a second element outlet.

[0100] Embodiment 10. A separation assembly according to any one of embodiments 1 to 9 and 11 to 21, wherein each of the plurality of microfluidic channels is nested with an adjacent microfluidic channel.

[0101] Embodiment 11. The separation assembly according to any one of embodiments 1 to 10 and 12 to 21, wherein the plurality of microfluidic channels comprises at least six microfluidic channels.

[0102] Embodiment 12. The separation assembly according to any one of embodiments 1 to 11 and 13 to 21, wherein each microfluidic channel is within 12 mm, 10 mm, 5 mm, or 3 mm of an adjacent microfluidic channel.

[0103] Embodiment 13. A separation assembly according to any one of embodiments 1 to 12 and 14 to 21, wherein each microfluidic channel is curved.

[0104] Embodiment 14. A separation assembly according to any one of embodiments 1 to 13 and 15 to 21, wherein each microfluidic channel defines two curves in opposite directions.

[0105] Embodiment 15. The separation assembly according to any one of embodiments 1 to 14 and 16 to 21, wherein each microfluidic channel has an inner wall and an outer wall, and each microfluidic channel is configured to concentrate particles in a liquid stream toward the inner wall.

[0106] Embodiment 16. A separation assembly according to any one of embodiments 1 to 15 and 17 to 21, wherein the length of each of the multiple microfluidic channels defines an arc of 270° or less.

[0107] Embodiment 17. A separation assembly according to any one of embodiments 1 to 16 and 18 to 21, wherein the length of each of the multiple microfluidic channels defines an arc of 200° or less.

[0108] Embodiment 18. The separation assembly according to any one of embodiments 1 to 17 and 19 to 21, wherein the microfluidic separation element is configured to separate particles in the range of 10 to 20 microns from a liquid stream.

[0109] Embodiment 19. The separation assembly according to any one of embodiments 1 to 18 and 20 to 21, wherein the microfluidic separation element is configured to separate one or both mammalian cells and insect cells in a liquid stream.

[0110] Embodiment 20. The separation assembly according to any one of embodiments 1 to 19 and 21, wherein the microfluidic separation element is configured to separate one or both fish cells and bird cells in a liquid stream.

[0111] Embodiment 21. A system comprising multiple isolation assemblies according to any one of Embodiments 1 to 20, wherein the isolation assemblies are arranged in a stack configuration, the system inlet is in direct fluid communication with each element inlet, and the multiple isolation assemblies are arranged to operate in parallel.

[0112] Embodiment 22. A hydrodynamic separator element comprising a substrate layer defining a layer inlet, a plurality of first layer outlets and second layer outlets, an outlet channel upstream of the second layer outlet, and a plurality of curved microfluidic channels arranged to operate in parallel, wherein each microfluidic channel defines a channel inlet downstream of the layer inlet, a first channel outlet upstream of the first layer outlet among the plurality of first layer outlets, and a second channel outlet upstream of the outlet channel, the substrate layer is impermeable, and each of the plurality of microfluidic channels is nested with an adjacent microfluidic channel.

[0113] Embodiment 23. A hydrodynamic separator element according to any one of Embodiments 22 and 24-38, wherein the length of each of the multiple curved microfluidic channels defines an arc of 270° or less.

[0114] Embodiment 24. A hydrodynamic separator element according to any one of Embodiments 22-23 and 25-38, wherein the length of each of the multiple curved microfluidic channels defines an arc of 200° or less.

[0115] Embodiment 25. A hydrodynamic separator element according to any one of embodiments 22-24 and 26-38, wherein each microfluidic channel defines two curves in opposite directions.

[0116] Embodiment 26. A hydrodynamic separator element according to any one of embodiments 22-25 and 27-38, wherein the plurality of curved microfluidic channels are at least six microfluidic channels.

[0117] Embodiment 27. A hydrodynamic separator element according to any one of embodiments 22-26 and 28-38, wherein each microfluidic channel is within 12 mm, 10 mm, 5 mm, or 3 mm of an adjacent microfluidic channel.

[0118] Embodiment 28. A hydrodynamic separator element according to any one of Embodiments 22-27 and 29-38, further comprising a permeate discharge layer in contact with a substrate layer, wherein the permeate discharge layer is located downstream of the first layer outlet.

[0119] Embodiment 29. A hydrodynamic separator element according to any one of Embodiments 22-28 and 30-38, wherein the permeate discharge layer extends laterally across the substrate layer.

[0120] Embodiment 30. A hydrodynamic separator element according to any one of Embodiments 22-29 and 31-38, wherein the permeate discharge layer is defined by a mesh material.

[0121] Embodiment 31. A hydrodynamic separator element according to any one of Embodiments 22-30 and 32-38, wherein the permeate discharge layer is a material layer defining microchannels downstream of a plurality of first layer outlets.

[0122] Embodiment 32. A hydrodynamic separator element according to any one of embodiments 22-31 and 33-38, wherein the hydrodynamic separator element is a component of a cell retention device of a perfusion bioreactor.

[0123] Embodiment 33. A hydrodynamic separator element according to any one of embodiments 22-32 and 34-38, wherein each microfluidic channel has an inner wall and an outer wall, and each microfluidic channel is configured to concentrate particles in a liquid stream toward the inner wall.

[0124] Embodiment 34. A hydrodynamic separator element according to any one of embodiments 22-33 and 35-38, wherein the hydrodynamic separator element is configured to separate particles in the range of 10-20 microns from a liquid stream.

[0125] Embodiment 35. A hydrodynamic separator element according to any one of embodiments 22-34 and 36-38, wherein the hydrodynamic separator element is configured to separate one or both mammalian cells and insect cells in a liquid stream.

[0126] Embodiment 36. A hydrodynamic separator element according to any one of embodiments 22-35 and 37-38, wherein the hydrodynamic separator element is configured to separate one or both fish cells and bird cells in a liquid stream.

[0127] Embodiment 37. A hydrodynamic separator element according to any one of embodiments 22 to 36 and 38, further comprising a plurality of substrate layers in a stack configuration and a system inlet that is in direct fluid communication with the inlet of each layer, wherein the plurality of substrate layers are arranged to operate in parallel.

[0128] Embodiment 38. A hydrodynamic separator element according to any one of Embodiments 22 to 37, further comprising a permeate discharge layer in contact with each substrate layer, wherein each permeate discharge layer is located downstream of the corresponding first layer outlet.

[0129] Embodiment 39. A hydrodynamic separator element having an element inlet, a plurality of first element outlets, a second element outlet, and a plurality of curved microfluidic channels between the element inlet and the first element outlets, wherein each curved microfluidic channel has an inner wall and an outer wall, and the hydrodynamic separator element is configured to concentrate particles along the inner wall; and a system comprising a tangential flow filter having a feed inlet downstream of the plurality of first element outlets, a retaining liquid outlet, a permeate outlet, and a filter medium disposed between the feed inlet and the permeate outlet.

[0130] Embodiment 40. The system according to any one of embodiments 39 and 41-59, further comprising a cell culture tank positioned downstream of the tangential flow filter.

[0131] Embodiment 41. A system according to any one of embodiments 39-40 and 42-59, wherein the hydrodynamic separator element comprises a substrate layer defining a layer inlet, a plurality of first layer outlets, and a second layer outlet, the layer inlet being located downstream of the element inlet, each first layer outlet being located upstream of the first element outlet of the plurality of first element outlets, the second layer outlet being located upstream of the second element outlet, and each of the plurality of curved microfluidic channels extending between the layer inlet and the first layer outlet of the plurality of first layer outlets.

[0132] Embodiment 42. The system according to any one of embodiments 39-41 and 43-59, further comprising a permeate discharge layer in contact with the substrate layer, wherein the permeate discharge layer is located downstream of the first layer outlet.

[0133] Embodiment 43. The system according to any one of Embodiments 39-42 and 44-59, wherein the permeate discharge layer extends laterally across the substrate layer.

[0134] Embodiment 44. A system according to any one of embodiments 39-43 and 45-59, wherein the hydrodynamic separator element comprises a plurality of substrate layers in a stack configuration, each substrate layer defining a layer inlet, a plurality of first layer outlets, a second layer outlet, and a curved microfluidic channel extending between the layer inlet and the first layer outlet of the plurality of first layer outlets, each layer inlet located downstream of the element inlet, each first layer outlet located upstream of the first element outlet, and each second layer outlet located upstream of the second element outlet.

[0135] Embodiment 45. The system according to any one of embodiments 39-44 and 46-59, further comprising a permeate discharge layer in contact with each substrate layer, wherein the permeate discharge layer is located downstream of a plurality of first layer outlets.

[0136] Embodiment 46. The system according to any one of Embodiments 39-45 and 47-59, wherein each permeate discharge layer extends laterally over the corresponding substrate layer.

[0137] Embodiment 47. The system according to any one of embodiments 39-46 and 48-59, wherein the permeate discharge layer is defined by a mesh material.

[0138] Embodiment 48. The system according to any one of embodiments 39-47 and 49-59, wherein the permeate discharge layer is a material layer that defines microchannels downstream of a plurality of first layer outlets.

[0139] Embodiment 49. The system according to any one of embodiments 39-48 and 50-59, wherein each substrate layer defines a plurality of curved microfluidic channels extending between a layer inlet and a first layer outlet among a plurality of first layer outlets.

[0140] Embodiment 50. The system according to any one of embodiments 39-49 and 51-59, wherein each of the multiple microfluidic channels is nested with an adjacent microfluidic channel.

[0141] Embodiment 51. The system according to any one of embodiments 39-50 and 52-59, wherein each substrate layer comprises at least six microfluidic channels.

[0142] Embodiment 52. The system according to any one of embodiments 39-51 and 53-59, wherein each microfluidic channel is within 12 mm, 10 mm, 5 mm, or 3 mm of an adjacent microfluidic channel within each substrate layer.

[0143] Embodiment 53. The system according to any one of embodiments 39-52 and 54-59, wherein each microfluidic channel is within 12 mm, 10 mm, 5 mm, or 3 mm of an adjacent microfluidic channel within each substrate layer.

[0144] Embodiment 54. The system according to any one of embodiments 39-53 and 55-59, wherein each microfluidic channel defines two curves in opposite directions.

[0145] Embodiment 55. The system according to any one of embodiments 39-54 and 56-59, wherein the length of each of the multiple curved microfluidic channels defines an arc of 270° or less.

[0146] Embodiment 56. The system according to any one of embodiments 39-55 and 57-59, wherein the length of each of the multiple curved microfluidic channels defines an arc of 200° or less.

[0147] Embodiment 57. The system according to any one of embodiments 39-56 and 58-59, wherein the hydrodynamic separator element is configured to separate particles in the range of 10-20 micrometers in diameter from the liquid stream.

[0148] Embodiment 58. The system according to any one of embodiments 39 to 57 and 59, wherein a hydrodynamic separator element is configured to separate one or both mammalian cells and insect cells in a liquid stream.

[0149] Embodiment 59. The system according to any one of embodiments 39 to 58, wherein a hydrodynamic separator element is configured to separate one or both fish cells and bird cells in a liquid stream.

[0150] It should also be noted that, as used herein and in the appended claims, the term “configured” describes a system, apparatus, or other structure that has been built to perform a particular task or to adopt a particular configuration. The term “configured” may be used interchangeably with similar terms such as “placed,” “built,” “manufactured,” etc.

[0151] All publications and patent applications contained herein represent the level of ordinary skill in the art to which the Art pertains. All publications and patent applications are incorporated herein by reference to the same extent as each individual publication or patent application would be explicitly indicated by reference. In the event of any inconsistency between the disclosures of this application and the disclosures of any documents incorporated herein by reference, the disclosures of this application shall prevail.

[0152] This application is intended to encompass adaptations or variations of the subject matter. The above description is illustrative and not limiting, and the claims are not limited to the exemplary embodiments described herein.

Claims

1. A hydrodynamic separator element, A substrate layer, Layer entrance and Multiple first layer outlets and second layer outlets, The outlet channel upstream of the second layer outlet, A plurality of curved microfluidic channels arranged to operate in parallel, wherein each microfluidic channel is The channel inlet downstream of the aforementioned layer inlet, A first channel outlet upstream of the first layer outlet among the plurality of first layer outlets, and a second channel outlet upstream of the outlet flow path Multiple microfluidic channels define and A substrate layer is provided to define the The substrate layer is impermeable, and each of the plurality of microfluidic channels is nested with an adjacent microfluidic channel. Hydrodynamic separator element.

2. The hydrodynamic separator element according to any one of claims 1 and 3 to 14, wherein the length of each of the plurality of curved microfluidic channels defines an arc of 200° or less.

3. A hydrodynamic separator element according to any one of claims 1 to 2 and 4 to 14, wherein each microfluidic channel defines two curves in opposite directions.

4. The hydrodynamic separator element according to any one of claims 1 to 3 and 5 to 14, wherein the plurality of curved microfluidic channels are at least six microfluidic channels.

5. A hydrodynamic separator element according to any one of claims 1 to 4 and 6 to 14, further comprising a permeate discharge layer in contact with the substrate layer, wherein the permeate discharge layer is located downstream of the plurality of first layer outlets.

6. The hydrodynamic separator element according to any one of claims 1 to 5 and 7 to 14, wherein the permeate discharge layer extends laterally across the substrate layer.

7. The hydrodynamic separator element according to any one of claims 1 to 6 and 8 to 14, wherein the permeate discharge layer is a material layer that defines microchannels downstream of the plurality of first layer outlets.

8. The hydrodynamic separator element according to any one of claims 1 to 7 and 9 to 14, wherein the permeate discharge layer is defined by a mesh material.

9. The hydrodynamic separator element according to any one of claims 1 to 8 and 10 to 14, wherein the hydrodynamic separator element is a component of a cell retention device of a perfusion bioreactor.

10. A hydrodynamic separator element according to any one of claims 1 to 9 and 11 to 14, wherein each microfluidic channel has an inner wall and an outer wall, and each microfluidic channel is configured to concentrate particles in a liquid stream toward the inner wall.

11. The hydrodynamic separator element according to any one of claims 1 to 10 and 12 to 14, wherein the hydrodynamic separator element is configured to separate particles in the range of 10 to 20 microns from a liquid stream.

12. The hydrodynamic separator element according to any one of claims 1 to 11 and 13 to 14, wherein the hydrodynamic separator element is configured to separate one or both mammalian cells and insect cells in a liquid stream.

13. Multiple substrate layers in a stack configuration, A hydrodynamic separator element according to any one of claims 1 to 12 and 14, further comprising a system inlet that directly communicates with the fluid at each layer inlet, wherein the plurality of substrate layers are arranged to operate in parallel.

14. The hydrodynamic separator element according to claim 13, further comprising a permeate discharge layer in contact with each substrate layer, wherein each permeate discharge layer is located downstream of the corresponding first layer outlet.

15. It is a separate assembly, A microfluidic separation element including a substrate layer, Element entry point, A plurality of first element outlets and second element outlets defined by the substrate layer A microfluidic separation element that defines, A permeate discharge layer that contacts the substrate layer and is located downstream of the plurality of first element outlets. A separate assembly comprising:

16. The separation assembly according to any one of claims 15 and 17 to 20, wherein the permeate discharge layer extends laterally across the substrate layer.

17. The separation assembly according to any one of claims 15-16 and 18-20, further comprising a first microfluidic channel, the first microfluidic channel defining a channel inlet downstream of the element inlet and defining a channel outlet having a first channel outlet upstream of the first element outlet of a plurality of first element outlets and a second channel outlet upstream of the second element outlet.

18. The separation assembly according to any one of claims 15 to 17 and 19 to 20, further comprising a plurality of microfluidic channels including the first microfluidic channel, wherein each microfluidic channel defines a channel inlet downstream of the element inlet, a first channel outlet upstream of the first element outlet of the plurality of first element outlets, and a second channel outlet upstream of the second element outlet.

19. The separation assembly according to any one of claims 15 to 18 and 20, wherein each of the plurality of microfluidic channels is nested with an adjacent microfluidic channel.

20. A plurality of separation assemblies according to any one of claims 15 to 19, wherein the separation assemblies are arranged in a stack configuration, A system comprising a system inlet that has direct fluid communication with each element inlet, wherein the plurality of isolation assemblies are arranged to operate in parallel.

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