Apparatus, system, chip and method for sorting particles within a sample
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-08-13
Smart Images
Figure IB2025053522_13082026_PF_FP_ABST
Abstract
Description
[0001] APPARATUS, SYSTEM, CHIP AND METHOD FOR SORTING PARTICLES WITHIN A SAMPLE
[0002] EARLIEST PRIORITY DATE:
[0003] This Application claims priority from a complete patent application filed in India having Patent Application No. 202531009552, filed on 04th day of February 2025, and titled “APPARATUS, SYSTEM, CHIP AND METHOD FOR SORTING PARTICLES WITHIN A SAMPLE”.
[0004] FIELD OF INVENTION
[0005] Embodiments of the present disclosure pertain to an apparatus and method for sorting particles within a sample based on their response to dielectrophoresis (DEP). More specifically, embodiments of the present disclosure focus on utilizing DEP to manipulate particles within a microfluidic system by leveraging their dielectric properties for precise orientation, sorting and analysis. The sample particles may include, but are not limited to, cells, DNA, RNA, proteins, or microorganisms, as well as particles from environmental, industrial, agricultural, clinical, pharmaceutical, food, forensic, or material science samples. This enables the separation of a diverse range of particles based on their unique responses to DEP forces, thereby extending the applicability of the disclosed apparatus and method to various fields of study and industry.
[0006] BACKGROUND
[0007] Dielectrophoresis (DEP) is a widely used technique in the manipulation and sorting of particles using non-uniform electric fields. The principle behind DEP is the generation of dielectrophoretic forces when a particle, typically suspended in a fluid, experiences a spatially varying electric field. The particle experiences a force that can be either attractive or repulsive depending on its dielectric properties relative to the surrounding medium.This makes DEP an effective method for sorting particles based on properties like size, shape, and electrical characteristics.
[0008] Microfluidic systems have significantly advanced the study and application of DEP by providing a controlled, compact environment for manipulating small volumes of fluid. These systems integrate multiple functionalities within microchannels, allowing precise control over fluid flow and particle manipulation. The use of microfluidic devices enables the sorting of particles with high precision, and in some cases, high throughput. However, despite their advantages, current DEP systems still face several limitations, particularly in the context of high-speed, high-throughput, and accurate sorting.
[0009] One major limitation in current DEP systems is the throughput, which is often constrained to only a few hundred cells per second. This limitation arises from the difficulty in efficiently manipulating particles, especially when using low-voltage electric fields or inefficient electrode designs. In many DEP systems, electrodes are designed with specific shapes and configurations that can handle only a limited number of particles at a time. When larger quantities of particles need to be processed, these systems become slower, and throughput is reduced, ultimately impacting the scalability and efficiency of the process. The design of the electrodes, the power levels applied, and the spatial configuration of the system all contribute to this limitation.
[0010] Another challenge with traditional DEP-based sorting systems is the difficulty in properly orienting non-uniform particles for detection. Many particles have irregular shapes, for example, cells, organelles (e.g., nuclei, mitochondria), extracellular vesicles (e.g., exosomes, microvesicles), polymer beads, protein aggregates, and viruses or anisotropic electrical properties, which make it challenging to orient them uniformly within the detection zone. Proper orientation is crucial for ensuring accurate detection, as misaligned particles may result in erroneous reading or ineffective sorting. In some DEP systems, the electric fields are insufficiently strong or do not interact with the particles in a manner that achieves consistent and precise orientation. As a result, DEP-based sorting may not be effective for handling a broad range of particle types, especially when those particles exhibit complex shapes or unique dielectric properties.Furthermore, flow focusing is an essential aspect of microfluidic systems for achieving laminar flow and preventing the dispersion of particles. However, in many DEP systems, flow focusing mechanisms are inadequate when it comes to handling actively moving particles, such as sperm cells, which may exhibit significant motility. Active matter like sperm cells can disrupt the flow and reduce the efficiency of sorting processes. The lack of effective flow focusing can lead to irregular particle positioning, preventing accurate particle manipulation and sorting. In such cases, the inability to control the flow of particles efficiently results in reduced throughput and compromised sorting performance.
[0011] Another issue related to particle sorting and detection in DEP systems is the challenge of accurately analyzing signals when multiple particles pass through the detection zone simultaneously. In many cases, particles are not interrogated individually, which leads to signal distortion. When groups of particles move through the detection zone at once, their signals can overlap, causing the optical or electrical signals to merge. This overlap makes it difficult for the system to distinguish between the different particles, leading to a loss of resolution in the detection process. When multiple particles move at varying speeds, their signals further become indistinguishable, producing similar readings for both fastmoving and slow-moving particles. This phenomenon significantly impairs the ability of the system to accurately classify and sort the particles based on their unique properties.
[0012] The distortion of signals in the detection zone becomes especially problematic when analyzing high-speed flows or sorting a large number of particles. In such cases, the detector may not differentiate between particles that are moving quickly and those that are moving slowly, as both will produce similar signals when grouped together. As a result, the system loses its capacity to accurately identify individual particles and their characteristics, thereby compromising the accuracy and efficiency of sorting. This is particularly critical in applications where high-throughput sorting is required, as the inability to separate and analyze individual particles leads to errors in the sorting process and may result in the loss of valuable data.Moreover, another technical challenge in DEP-based systems is the requirement for high voltage fields to effectively manipulate particles. Many conventional DEP systems use electrodes that require high voltages to generate the necessary electric fields for particle manipulation. However, the use of high voltages presents safety concerns and can lead to unwanted heating of the system, damaging delicate samples, for example, samples or affecting the system's overall performance. Furthermore, the electrode shapes and configurations often necessitate these high voltages, which can limit the practical use of DEP systems in environments where lower voltages are preferred to prevent damage to cells or to meet specific experimental requirements.
[0013] Thus, there is a pressing need to provide an improved approach to overcome these challenges and provide faster, more accurate, and more reliable sorting of particles within a sample for a wide range of applications.
[0014] BRIEF DESCRIPTION
[0015] In accordance with an embodiment of the present disclosure an apparatus for sorting particles within a sample is provided. The apparatus includes a primary microchannel having a central axis where the primary microchannel includes a focusing zone formed within the primary microchannel, wherein the focusing zone includes: a first electrode arrangement having a first microelectrode strip with a first longitudinal axis to the central axis having a set of first fingers protruding periodically and extending perpendicularly to the central axis from a first region of the first microelectrode strip and a second microelectrode strip with a second longitudinal axis parallel to the central axis having a set of second fingers protruding periodically and extending perpendicularly to the central axis from a second region of the second microelectrode strip, wherein each first finger from the set of first fingers faces a corresponding second finger from the set of second fingers, wherein the first microelectrode strip and the second microelectrode strip are positioned at opposite sides of the central axis. The apparatus further includes a second electrode arrangement, wherein the second electrode arrangement includes a third microelectrode strip with a third longitudinal axis parallel to the central axis having a setof third fingers protruding periodically and extending perpendicularly to the central axis from a third region of the third microelectrode strip and a fourth microelectrode strip with a fourth longitudinal axis parallel to the central axis having a set of fourth fingers protruding periodically and extending perpendicularly to the central axis from a fourth region of the fourth microelectrode strip, wherein each third finger from the set of third fingers faces a corresponding fourth finger from the set of fourth fingers, wherein the second electrode arrangement is adjacent to the first electrode arrangement and separated by a predetermined offset such that the third longitudinal axis aligns with the first longitudinal axis and the fourth longitudinal axis aligns with the second longitudinal axis, Alternatively, the microelectrode strips may be provided with no fingers protruding from them.
[0016] In accordance with another embodiment of the present disclosure, a system for sorting particles within a sample is provided. The system includes a processing unit optically coupled with a tapered region of a primary microchannel of an apparatus described in an embodiment of the present disclosure. The processing unit is configured to capture a respective resultant light interactions between each particle of the particles and a laser light upon shining on the each particle via a laser source and high-speed electronics in data communication with the processing unit. The high-speed electronics are configured to analyze the respective resultant light interactions. Further, the high-speed electronics are configured to cause flow of a particle corresponding to the respective resultant light interactions towards a dedicated flow channel using dielectrophoresis based on the analysis.
[0017] In accordance with yet another embodiment of the present disclosure a chip for sorting particles within a sample is provided. The chip includes a substrate. The substrate includes an apparatus described in an embodiment of the present disclosure fabricated on it.
[0018] In accordance with another embodiment of the present disclosure a method for sorting particles in a sample using an apparatus described in an embodiment of the present disclosure is provided. The method includes introducing the sample into the apparatus, subjecting the sample to dielectrophoretic and hydrodynamic focusing in the focusing zone, orienting each particle of the particles individually and sequentially in theorientation zone, shining a laser light on the each particle in the detection zone, wherein the each particle is optionally fluorescence stained in the detection zone, capturing a respective resultant optical interaction between the each particle and the laser light, analyzing the respective resultant optical interaction to identify a corresponding particle of the particles as desirable or undesirable based on one or more properties and based on the analysis, cause the corresponding particle to flow into a dedicated flow channel or another flow channel branched from same pathway and adjacent to the dedicated flow channel of the apparatus.
[0019] To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the disclosure and are therefore not to be considered limiting in scope. The disclosure will be described and explained with additional specificity and detail with the appended figures.
[0020] BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The disclosure will be described and explained with additional specificity and detail with the accompanying figures in which:
[0022] FIG. 1 illustrates schematic representation of an apparatus in accordance with an embodiment of the present disclosure.
[0023] FIG. 2 illustrates a schematic representation depicting inlet and outlet ports of an apparatus as illustrated in FIG. 1, in accordance with an embodiment of the present disclosure.
[0024] FIGS. 3a-3b illustrate a schematic representation of an electrode arrangement provided in a focusing zone of an apparatus in accordance with an embodiment of the present disclosure.
[0025] FIG. 4 illustrates a schematic representation of focusing zone of an apparatus as illustrated in FIG. 1 in accordance with an embodiment of the present disclosure.FIG. 5 illustrates a schematic representation of interdigitated electrode array provided in an orientation zone of an apparatus as illustrated in FIG. 1 in accordance with an embodiment of the present disclosure.
[0026] FIG. 6 illustrates a schematic representation of orientation zone of an apparatus as illustrated in FIG. 1 in accordance with an embodiment of the present disclosure.
[0027] FIG. 7 illustrates a schematic representation of a tapered region of an apparatus illustrated in FIG. 1 without the corresponding electrode disposal in accordance with an embodiment of the present disclosure.
[0028] FIG. 8 illustrates a schematic representation of different zones of an apparatus illustrated in FIG. 1 with the corresponding electrode disposed in accordance with an embodiment of the present disclosure.
[0029] FIG. 9 illustrates a schematic representation of deflection of a particle using an apparatus illustrated in FIG. 1 in accordance with an embodiment of the present disclosure
[0030] FIG. 10 illustrates a block diagram of a system employing an apparatus illustrated in FIG.
[0031] 1 in accordance with an embodiment of the present disclosure.
[0032] FIG. 11 illustrates a flow chart depicting method steps involved in a method in accordance with an embodiment of the present disclosure.
[0033] Further, those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.
[0034] DETAILED DESCRIPTIONFor the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.
[0035] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more devices or subsystems or elements or structures or components preceded by " comprises... a" does not, without more constraints, preclude the existence of other devices, sub-systems, elements, structures, components, additional devices, additional sub-systems, additional elements, additional structures or additional components. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.
[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.
[0037] In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
[0038] In accordance with an embodiment of the present disclosure an apparatus for sorting particles within a sample is provided. The apparatus includes a primary microchannel having a central axis where the primary microchannel includes a focusing zone formed within the primary microchannel, wherein the focusing zone includes: a first electrode arrangement having a first microelectrode strip with a first longitudinal axis to the centralaxis having a set of first fingers protruding periodically and extending perpendicularly to the central axis from a first region of the first microelectrode strip and a second microelectrode strip with a second longitudinal axis parallel to the central axis having a set of second fingers protruding periodically and extending perpendicularly to the central axis from a second region of the second microelectrode strip, wherein each first finger from the set of first fingers faces a corresponding second finger from the set of second fingers, wherein the first microelectrode strip and the second microelectrode strip are positioned at opposite sides of the central axis. The apparatus further includes a second electrode arrangement, wherein the second electrode arrangement includes a third microelectrode strip with a third longitudinal axis parallel to the central axis having a set of third fingers protruding periodically and extending perpendicularly to the central axis from a third region of the third microelectrode strip and a fourth microelectrode strip with a fourth longitudinal axis parallel to the central axis having a set of fourth fingers protruding periodically and extending perpendicularly to the central axis from a fourth region of the fourth microelectrode strip, wherein each third finger from the set of third fingers faces a corresponding fourth finger from the set of fourth fingers, wherein the second electrode arrangement is adjacent to the first electrode arrangement and separated by a predetermined offset such that the third longitudinal axis aligns with the first longitudinal axis and the fourth longitudinal axis aligns with the second longitudinal axis, Alternatively, the microelectrode strips may be provided with no fingers protruding from them.
[0039] FIG. 1 illustrates schematic representation of an apparatus in accordance with an embodiment of the present disclosure. The apparatus may be made from, but not limited to, silicate glass, quartz glass, calcium fluoride glass, PDMS (polydimethylsiloxane) or PMMA (polymethyl methacrylate). In some examples, the apparatus may preferably be made from quartz glass. Further, FIG. 2 illustrates a schematic representation depicting inlet and outlet ports of an apparatus as illustrated in FIG. 1, in accordance with an embodiment of the present disclosure. Referring to FIGS. 1-2, the apparatus for sorting particles within a sample includes a primary microchannel (11 or 21). The primary microchannel has a central axis (A-A’). The primary microchannel (11 or 21) has a first inlet (22) through which the sample may be injected into the primary microchannel.Further, the apparatus may include a second inlet (23) alternatively, referred to as sheath inlet is configured to allow a sheath fluid, which is biologically compatible with the sample, injected therein to flowthrough a pair of secondary channels (27, 27’) branching from the second inlet, each intersecting perpendicularly the primary microchannel at contrary sides at a specific location along the axial direction of the primary microchannel, thereby compressing the sample flowing from the first inlet, resulting in hydrodynamic focusing of the sample. The expression “sheath fluid is biologically compatible with the sample” is intended to mean that the sheath fluid is “non-toxic”, “non hostile”, or “lethal” to the sample.
[0040] The different zones as shown in FIG. 1 include a focusing zone (12) comprising a pair of electrode arrangements, an orientation zone (13) comprising a pair of interdigitated arrays downstream to the focusing zone (12), a detection zone (14) comprising a pair of detection electrodes downstream to the orientation zone (13), and a deflection zone (15) comprising a set of deflection electrodes downstream to the detection zone (14). As further shown in FIG. 2, the primary microchannel at the end of deflection zone may be branched into three channels, each having its own inlet (24, 25).
[0041] It may be noted here that the dimensions of the primary microchannel may be selected considering the hydrodynamic resistance and dielectrophoretic force profile in the primary microchannel cross section to facilitate optimal sorting of the particles within the sample.
[0042] FIGS. 3a-3b illustrate a schematic representation of an electrode arrangement provided in a focusing zone of an apparatus as illustrated in FIG. 1 in accordance with an embodiment of the present disclosure. An electrode arrangement (30) as shown in Fig. 3a comprises a first microelectrode strip (31) with a first longitudinal axis (F-F’) parallel to the central axis (A- A’ as shown in FIG. 2), comprising a first set of fingers (312-1 to 312-N) protruding periodically and extending perpendicularly to the central axis (A- A’ as shown in FIGI) from a first region (310) of the first microelectrode strip (31). Further, the electrode arrangement (30) comprises a second microelectrode strip (32) with a second longitudinal axis (S-S’) parallel to the central axis (A-A’ as shown in FIG. 1), comprisinga second set of fingers (321-1 to 321-N) protruding periodically and extending perpendicularly to the central axis from a second region (320) of the second microelectrode strip (32), wherein each first finger from the set of first fingers (312-1 to 312-N) faces a corresponding second finger from the set of second fingers (321-1 to 321 -N), wherein the first microelectrode strip and the second microelectrode strip are positioned at opposite sides of the central axis (A-A’). A second electrode arrangement (not shown) structurally same as the first electrode arrangement and aligned with the first electrode arrangement is provided on a second inner surface opposite to the first inner surface of the primary microchannel. In other words, the second electrode arrangement comprise a third microelectrode strip with a third longitudinal axis parallel to the central axis, comprising a third set of fingers protruding periodically and extending perpendicularly to the central axis (A-A’ as shown in FIG.1) from a third region of the third microelectrode strip; and a fourth microelectrode strip with a fourth longitudinal axis parallel to the central axis, comprising a fourth set of fingers protruding periodically and extending perpendicularly to the central axis (A-A’ as shown in FIG.l) from a fourth region of the fourth microelectrode strip, wherein each third finger from the set of third fingers faces a corresponding fourth finger from the set of fourth fingers, wherein the second electrode arrangement is adjacent to the first electrode arrangement and separated by a predetermined offset such that the third longitudinal axis aligns with the first longitudinal axis (F-F’) and the fourth longitudinal axis aligns with the second longitudinal axis (S-S’).
[0043] Alternatively, in another implementation, each microelectrode strip (31 A, 32A) with no fingers protruding from the respective regions of the microelectrode strips (31 A, 32A) may be arranged in the focusing zone similar to the arrangement above as shown in Figure. 3b.
[0044] It may be noted here that every electrode utilized in the present invention may be made of gold, platinum, aluminum or aluminum-based alloy. However, any other metal or metal-alloy rendering the same or optimized results as aluminum or aluminum-based alloy may be utilized. This application is not limited thereto.Although FIG. 3a depicts the fingers as having a rectangular shape, in another example, any geometric shape that performs a similar function, such as triangular, trapezoidal, or curved shapes, may also be utilized without departing from the scope of the invention. Further, in an example, the separation between the first region and the second region is greater than the separation between the first set of fingers and the second set of fingers in the first electrode arrangement, facilitating the generation of steep electric potential gradients at lower voltages, with the same configuration applied to the second electrode arrangement.
[0045] Furthermore, the first microelectrode strip (31, 31 A) and the fourth microelectrode strip are configured to have a first polarity and the second microelectrode (32, 32A) strip and the third microelectrode strip are configured to have a second polarity different from the first polarity.
[0046] FIG. 4 provides a schematic representation of the focusing zone of the apparatus illustrated in FIG. 1, in accordance with an embodiment of the present disclosure. As depicted, the first electrode arrangement (comprising the first microelectrode strip 41 and the second microelectrode strip 42) and the second electrode arrangement (comprising the third microelectrode strip 43 and the fourth microelectrode strip 44) are configured to have alternating polarity. This arrangement creates a non-uniform electric field, with high-energy zones or high electric fields (45, 46 and 48) forming across the cross-section of the primary microchannel (11, 21) due to abrupt potential changes caused by the proximity of the set of fingers (312-1 to 312-N and 321-1 to 321-N as shown in Fig. 3a or the microelectrode strips (31 A and 32A) shown in fig. 3b). In contrast, low-energy zone or low electric field (40) is established along the central axis of the primary microchannel, where the potential gradient gradually decreases.
[0047] When operating in the negative DEP (nDEP) regime, particles, having a lower effective permittivity than the surrounding medium, are repelled from the high-field regions across the cross-section of the primary microchannel. This repulsive force directs the particles toward the central low-energy zone. The gradual potential variations in this zone result in a stable environment, promoting the particles (particle 47) alignment along the primarymicrochannel's axis (A-A’). Consequently, the particles 47 are guided into a near-linear path, ensuring precise positioning for downstream detection and sorting.
[0048] FIG. 5 illustrates a schematic representation of interdigitated electrode array provided in an orientation zone of an apparatus as illustrated in FIG. 1, in accordance with an embodiment of the present disclosure. As shown therein, an interdigitated electrode array (50) comprises a first microelectrode (51) having a plurality of first fingers (512-1 to 512-N) protruding periodically from a first base region (510) of the first microelectrode (51) and a second microelectrode (52) having a plurality of second fingers (521-1 to 521-N)) protruding periodically from a second base region (520) of the second microelectrode (52), wherein the plurality of first fingers (512-1 to 512-N) and the plurality of second fingers (521-1 to 521-N) interdigitate, creating gaps between them.
[0049] A pair of such interdigitated electrode arrays i.e., a first interdigitated electrode array and a second interdigitated electrode array are disposed longitudinally along the central axis (A-A’) and on the opposite inner surfaces of the primary microchannel (11, 21) such that interdigitation of fingers in the first interdigitated electrode array is repeated and aligned with interdigitation of fingers in the second interdigitated electrode array. Further, a first microelectrode corresponding to the first interdigitated electrode array is configured to have an opposite polarity relative to the second microelectrode corresponding to the first interdigitated electrode array. Furthermore, the first microelectrode corresponding to the first interdigitated electrode array is configured to have an opposite polarity relative to the first microelectrode corresponding to the second interdigitated electrode array. Even further, the second microelectrode corresponding to the first interdigitated electrode array is configured to have an opposite polarity relative to the second microelectrode corresponding to the second interdigitated electrode array.
[0050] FIG. 6 illustrates a schematic representation of orientation zone of an apparatus as illustrated in FIG. 1 in accordance with an embodiment of the present disclosure. As shown therein, because of the interdigitated electrode arrays (61 and 62) arrangement in the orientation zone, high energy zones or high electric fields (63 and 64) are formed across the cross-section of the primary microchannel (11, 21) and a low energy zone orlow electric field (65) is formed along the central axis (A- A’) of the primary microchannel. This arrangement orients the particles (for clarity, a particle 60 is shown in Fig. 6) along the central axis (A-A’), thereby ceasing any rotational or irregular movement of the particles.
[0051] FIG. 7 illustrates a schematic representation of a tapered region of an apparatus illustrated in FIG. 1 without the corresponding electrode disposal in accordance with an embodiment of the present disclosure. FIG. 8 illustrates a schematic representation of different zones of an apparatus illustrated in FIG. 1 with the corresponding electrode disposed in accordance with an embodiment of the present disclosure. Referring to FIGS. 7-8, as shown therein, the primary microchannel (11, 21) includes a tapered region (71) downstream of the orientation zone (70). After the tapered region (71), the primary microchannel transitions into a narrow channel (72, 83) with reduced dimensions, which then branches into three separate flow channels (73, 74, 75), each having a corresponding inlet at the branching region (76). The three separate flow channels include two side flow channels (73, 74) and one middle flow channel (75). The tapered region (71) defines a detection zone (81). The detection zone (81) is where the oriented particle from the orientation zone (70) is subjected to optical analysis. The narrow channel (72, 83) defines a deflection zone (15 as shown in Fig. 1).
[0052] As further shown therein, the detection zone (81) comprises a pair of primary deflection electrodes (82, 82’) disposed of the opposite inner surfaces of the primary microchannel (11, 21) such that the primary deflection electrodes (82, 82’) face each other across the central axis, wherein the pair of detection electrodes (82, 82’) are configured to have a different polarity.
[0053] Now referring to FIGS. 7-8, the deflection zone includes a set of first deflection electrodes (84-1 to 84-N), where the first deflection electrodes in this set are arranged at a predefined offset. Similarly, the deflection zone includes a set of second deflection electrodes (85-1 to 85-N), with the second electrodes positioned at the same offset as the first electrodes. Although the sets of deflection electrodes are depicted in the drawings as being located on the outer surface of the narrow channel (72, 83) for clarity, in practice, the electrodesare positioned on the opposite inner surfaces of the primary microchannel (11, 21), wherein the set of first deflection electrodes (84-1 to 84-N) and the set (85-1 to 85-N) are disposed of the opposite inner surfaces of the primary microchannel (11, 21), wherein the first deflections electrodes are configured to have an alternating polarity and the second deflection electrodes are configured to have the alternating polarity, wherein a first deflection electrode of the set of first deflection electrodes (84-1 to 84-N) facing a corresponding second deflection electrode of the set of second deflection electrodes (85-1 to 85-N) has a same polarity.
[0054] Further, a set of electrodes (86) are placed at mouth of the middle flow channel (75), extending along the interior surfaces- top, bottom, and side surfaces of the middle flow channel.
[0055] It is to be noted here that A-A’ is also the central axis of the narrow channel (72, 83). In the microfluidic apparatus of the present invention, the flow through the branching region (76) occurs within a short time frame due to the inherently rapid dynamics of the microfluidic design. In such a short time frame, the flow does not naturally change its trajectory solely due to hydrodynamic forces unless acted upon by an external force. This is because the hydrodynamic timescale far exceeds the residence time in the deflection zone. The fluid flow in microchannels follows laminar flow principles, where it adheres to well-defined streamlines with minimal lateral dispersion, which is effectively determined in the upstream focusing zone.
[0056] Therefore, for the flow to deviate from the central streamline and enter one of the side flow channels (73, 74), an external force, such as dielectrophoretic forces generated by strategically placed electrodes, must be applied. A single dielectrophoretic force pulse can act quickly and precisely to alter the flow's path within a time frame much shorter than the hydrodynamic timescale, fitting the limited time available in the branching deflection region (76). Simultaneously, a negative dielectrophoretic pulse from electrodes (86) at the mouth of the middle flow channel (75) ensures that any undesirable flow is repelled and does not enter the middle flow channel.Without such an external force, or in the absence of sufficient time for natural diffusion or other slower mechanisms to influence the flow’s trajectory, the flow continues along the central streamline into the path of least resistance - the middle flow channel (75). Thus, the apparatus leverages this time-sensitive behaviour to ensure that only selectively deflected particles enter the side channels, while non-deflected particles are guided to the middle flow channel (75), maintaining sorting precision and efficiency.
[0057] FIG. 9 illustrates a schematic representation of deflection of a particle using an apparatus illustrated in FIG. 1 in accordance with an embodiment of the present disclosure. As depicted therein, a particle 90, which has been identified as undesirable based on analysis of a corresponding light interactions of the particle 90 with a laser light shined upon it, has been deflected towards a dedicated flow channel (74) of the three flow channels (73, 74, 75).
[0058] In accordance with another embodiment of the present disclosure, a system for sorting particles within a sample is provided. The system includes a processing unit optically coupled with a tapered region of a primary microchannel of an apparatus described in an embodiment of the present disclosure. The processing unit is configured to capture a respective resultant light interactions between each particle of the particles and a laser light upon shining on the each particle via a laser source and high-speed electronics in data communication with the processing unit. The high-speed electronics are configured to analyze the respective resultant light interactions. Further, the high-speed electronics is configured to cause flow of a particle corresponding to the respective resultant light interactions towards a dedicated flow channel based on the analysis.
[0059] FIG. 10 illustrates a block diagram of a system employing an apparatus illustrated in FIG.
[0060] 1 in accordance with an embodiment of the present disclosure. The system (100) may include a processing unit (106) optically coupled with the tapered region (71) of the primary microchannel (11, 21) of the apparatus (10). The processing unit (106) is configured to capture resultant light interactions between the particles and a laser light upon shining on the particles via a laser source (104) and high-speed electronics (108) in data communication with the processing unit, wherein the high-speed electronics areconfigured to analyze the resultant light interactions, thereby causing the flow of a particle corresponding to the respective resultant light interactions towards a dedicated flow channel based on the analysis. It may be noted here that optical communication between the laser source (104), the apparatus and the processing unit may be established by optical fibers (104a, 104b-l to 104b-3).
[0061] In accordance with yet another embodiment of the present disclosure a chip for sorting particles within a sample is provided. The chip includes a substrate (not shown). The substrate includes an apparatus (10) described in an embodiment of the present disclosure fabricated on it.
[0062] FIG. 11 illustrates a flow chart depicting method steps involved in a method (1100) for sorting particles within a sample in accordance with an embodiment of the present disclosure.
[0063] In accordance with another embodiment of the present disclosure a method for sorting particles in a sample using the apparatus described above is provided. The method includes introducing the sample into the apparatus (10), subjecting the sample to hydrodynamic focusing in the focusing zone, orienting each particle of the particles individually and sequentially in the orientation zone, shining a laser light on the each particle in the detection zone, wherein the each particle is optionally fluorescence stained in the detection zone, capturing a respective resultant optical interaction between the each particle and the laser light, analyzing the respective resultant optical interaction to identify a corresponding particle of the particles as desirable or undesirable based on one or more properties and based on the analysis, cause the corresponding particle to flow into a dedicated flow channel or another flow channel branched from same pathway and adjacent to the dedicated flow channel of the apparatus.
[0064] At block 1102, the sample may be introduced into the apparatus (10).
[0065] At block 1104, the sample may be subjected to hydrodynamic focusing in the focusing zone.At block 1106, each particle of the sample may individually and sequentially oriented in the orientation zone using dielectrophoresis.
[0066] At block 1108, a laser light on the each particle in the detection zone may be shined, wherein the each particle is optionally fluorescence stained in the detection zone.
[0067] At block 1110, a respective resultant optical interaction between the each particle and the laser light may be captured.
[0068] At block 1112, the respective resultant optical interaction to identify a corresponding particle of the particles as desirable or undesirable based on one or more properties may be analyzed.
[0069] At block 1114, based on the analysis, the corresponding particle to flow into a dedicated flow channel (for example, flow channels 73 and 74) or another flow channel (for example, flow channel 75) branched from same pathway and adjacent to the dedicated flow channel of the apparatus may be caused.
[0070] At block 1114, when the corresponding particle is identified as undesirable the corresponding particle may be caused to fall into the dedicated flow channel. The causing may include:
[0071] subjecting the corresponding particle to negative di electrophoretic forces in the detection zone;
[0072] subsequently subjecting the corresponding particle to AC positive di electrophoretic forces in the deflection zone; and
[0073] contemporaneously subjecting the corresponding particle to an AC negative dielectrophoretic pulse provided by an electrode at the mouth of the another flow channel, thereby ensuring the particle successfully flows into the dedicated flow channel.
[0074] At block 1114, when the corresponding particle is identified as desirable causing the corresponding particle to fall into another flow channel, wherein causing comprises:allowing the corresponding particle to flow naturally into the another flow channel in the absence of dielectrophoresis forces when axis of the another flow channel is same as axis of the primary microchannel.
[0075] The present invention provides several technical advantages of high throughput, precise orientation, and efficient handling of non-uniform and motile particles in particle sorting. Particularly, in the present invention, the focusing zone incorporates a microelectrode arrangement that creates regions of high electric potential near the electrode surfaces, forming a low-energy zone aligned with the central axis of the channel. This design utilizes negative dielectrophoresis (nDEP) to push particles toward the low-energy zone, achieving near-streamlined motion. This is particularly effective for actively moving cells, such as sperm cells, ensuring their efficient flow for subsequent processing.
[0076] Upon exiting the focusing zone, particles enter the orientation zone, where dielectrophoretic forces generated by strategically positioned electrodes align the axes of irregularly shaped cells with the central axis of the channel. This precise alignment optimally positions the particles for optical analysis in the subsequent detection zone, enabling accurate analysis even for complex particle shapes.
[0077] Following the optical analysis, particles are deflected toward designated outlets based on their detected properties. The apparatus employs a sequential deflection mechanism, wherein electrodes in the detection zone first guide the particles toward the deflection zone, where they are further redirected. This two-stage deflection process minimizes the travel path of particles, ensuring faster and more efficient sorting. By directing particles with precision and speed to their respective outlets, the apparatus significantly enhances sorting accuracy and throughput.
[0078] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.
[0079] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in theart, various working modifications may be made to the method in order to implement the inventive concept as taught herein.
[0080] The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, the order of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts need to be necessarily performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples.
Claims
I CLAIM:
1. An apparatus (10) for sorting particles within a sample comprising:a primary microchannel (11, 21) having a central axis (A- A’), wherein the primary microchannel (11, 21) comprises:a focusing zone (12) formed within the primary microchannel, wherein the focusing zone (12) comprises:a first electrode arrangement (30), wherein the first electrode arrangement comprises:a first microelectrode strip (31) with a first longitudinal axis (F-F’) parallel to the central axis (A- A’), comprising a set of first fingers (312-1 to 312-N) protruding periodically and extending perpendicularly to the central axis (A- A’) from a first region (310) of the first microelectrode strip; anda second microelectrode strip (32) with a second longitudinal axis (S-S’) parallel to the central axis (A-A’), comprising a set of second fingers (321-1 to 321-N) protruding periodically and extending perpendicularly to the central axis (A-A’) from a second region (320) of the second microelectrode strip (320), wherein each first finger from the set of first fingers (312-1 to 312-N) faces a corresponding second finger from the set of second fingers (321-1 to 321-N), wherein the first microelectrode strip and the second microelectrode strip are positioned at opposite sides of the central axis (A-A’); anda second electrode arrangement, wherein the second electrode arrangement comprises:a third microelectrode strip with a third longitudinal axis parallel to the central axis (A-A’), comprising a set of third fingers protruding periodically and extending perpendicularly to the central axis (A-A’) from a third region of the third microelectrode strip; anda fourth microelectrode strip with a fourth longitudinal axis parallel to the central axis (A-A’), comprising a set of fourth fingers protruding periodically and extending perpendicularly to the central axis (A-A’) froma fourth region of the fourth microelectrode strip, wherein each third finger from the set of third fingers faces a corresponding fourth finger from the set of fourth fingers, wherein the second electrode arrangement is adjacent to the first electrode arrangement and separated by a predetermined offset such that the third longitudinal axis aligns with the first longitudinal axis (F-F’) and the fourth longitudinal axis aligns with the second longitudinal axis (S-S’);ora first electrode arrangement (30), wherein the first electrode arrangement comprises:a first microelectrode strip (31 A) with a first longitudinal axis (FF- FF’) parallel to the central axis (A-A’); anda second microelectrode strip (32A) with a second longitudinal axis (SS-SS’) parallel to the central axis (A-A’), wherein the first microelectrode strip and the second microelectrode strip are positioned at opposite sides of the central axis (A-A’); anda second electrode arrangement, wherein the second electrode arrangement comprises:a third microelectrode strip with a third longitudinal axis parallel to the central axis (A-A’); anda fourth microelectrode strip with a fourth longitudinal axis parallel to the central axis (A-A’), wherein the second electrode arrangement is adjacent to the first electrode arrangement and separated by a predetermined offset such that the third longitudinal axis aligns with the first longitudinal axis (F-F’) and the fourth longitudinal axis aligns with the second longitudinal axis (S-S’);an orientation zone;a detection zone; anda deflection zone.
2. The apparatus as claimed in claim 1, wherein the first microelectrode strip (31) and the fourth microelectrode strip are configured to have a first polarity, and the secondmicroelectrode strip (32) and the third microelectrode strip are configured to have a second polarity different from the first polarity.
3. The apparatus as claimed in claim 1, wherein the primary microchannel (11, 21) comprises a first inlet (22) configured to allow the sample injected therein to flow through the focusing zone (12).
4. The apparatus as claimed in claim 3, further comprises a second inlet (23), wherein the second inlet (23) is configured to allow sheath fluid injected therein to flow through a pair of secondary microchannels (27, 27’) that intersect perpendicularly with the primary microchannel (11, 21) at opposite sides, thereby compressing the sample flowing from the first inlet (22), resulting in hydrodynamic focusing of the sample, wherein the sheath fluid is biologically compatible with the sample.
5. The apparatus as claimed in claim 1, wherein the orientation zone (13) is downstream of the focusing zone (12), wherein the orientation zone (13) comprises a first interdigitated electrode array (50) and a second interdigitated electrode array, each disposed longitudinally along the central axis (A- A’) and on the opposite inner surfaces of the primary microchannel (11, 21), each interdigitated electrode array comprises: a first microelectrode (51) having a plurality of first fingers (512-1 to 512-N) protruding periodically from a first base region (510) of the first microelectrode (51); and a second microelectrode (52) having a plurality of second fingers (521-1 to 521-N) protruding periodically from a second base region (520) of the second microelectrode (52), wherein the plurality of first fingers (512-1 to 512-N) and the plurality of second fingers (521-1 to 521 -N) interdigitate, creating gaps between them, wherein interdigitation of fingers in one interdigitated electrode array is repeated and aligned with interdigitation of fingers in another interdigitated electrode array.
6. The apparatus as claimed in claim 5, wherein the first microelectrode corresponding to the first interdigitated electrode array is configured to have an opposite polarity relative to the second microelectrode corresponding to the first interdigitated electrode array, wherein the first microelectrode corresponding to the first interdigitated electrode array is configured to have an opposite polarity relative to the first microelectrode corresponding to the second interdigitated electrode array, wherein the second microelectrode corresponding to the first interdigitated electrode array isconfigured to have an opposite polarity relative to the second microelectrode corresponding to the second interdigitated electrode array.
7. The apparatus as claimed in claim 1, wherein the primary microchannel (11, 21) comprises a tapered region (71) downstream of the orientation zone (13, 70), defining the detection zone (14, 81), wherein the detection zone (14, 81) comprises a pair of primary deflection electrodes (82, 82’) disposed of the opposite inner surfaces of the primary microchannel 11, 21) such that the primary deflection electrodes electrodes (82, 82’) face each other across the central axis (A-A’), wherein the pair of primary deflection electrodes (82-82’) are configured to have a different polarity.
8. The apparatus as claimed in claim 1, wherein the deflection zone (15) is downstream of the detection zone (14), wherein the deflection zone (15) comprises: a set of first deflection electrodes (84-1 to 84-N), wherein first deflection electrodes in the set of first deflection electrodes (84-1 to 84-N) are positioned at a predefined offset; anda set of second deflection electrodes (85-1 to 85-N), wherein second deflection electrodes in the set of second deflection electrodes (85-1 to 85-N) are positioned at the predefined offset,wherein the set of first deflection electrodes (84-1 to 84-N) and the set (85-1 to 85-N) are disposed of the opposite inner surfaces of the primary microchannel (11, 21), wherein the first deflections electrodes are configured to have an alternating polarity and the second deflection electrodes are configured to have the alternating polarity, wherein the first deflection electrode facing the second deflection electrode has a same polarity.
9. The apparatus as claimed in claim 1, further comprising three flow channels (73, 74, 75), each having a corresponding inlet, wherein the primary microchannel (11, 21) transitions into a narrow channel (72, 83), from which the three flow channels (73, 74, 75) branch out.
10. The apparatus as claimed in claim 9, wherein the three flow channels comprise two side flow channels (73, 75) and one middle flow channel (74), wherein a set of electrodes (86) is provided at mouth of the middle flow channel.
11. A system (100) for sorting particles within a sample comprising:a processing unit (106) optically coupled with the tapered region of the primary microchannel of the apparatus (10, 102) as claimed in claim 1, wherein the processing unit (106) is configured to capture a respective resultant light interactions between each particle of the particles and a laser light upon shining on the each particle via a laser source (104); andhigh-speed electronics (108) in data communication with the processing unit (106), wherein the high-speed electronics (108) are configured to:analyze the respective resultant light interactions;based on the analysis, cause flow of a particle corresponding to the respective resultant light interactions towards a dedicated flow channel.
12. A chip for sorting particles within a sample, comprising:a substrate, wherein the substrate comprises the apparatus (10, 102) as claimed in claim 1 fabricated on it.
13. A method (1100) for sorting particles within a sample employing the apparatus (10, 102) as claimed in claim 1, wherein the method (1100) comprises:introducing (1102) the sample into the apparatus (10, 102);subjecting (1104) the sample to hydrodynamic focusing in the focusing zone; orienting (1106) each particle of the particles individually and sequentially in the orientation zone using dielectrophoresis.shining (1108) a laser light on the each particle in the detection zone, wherein the each particle is optionally fluorescence stained in the detection zone;capturing (1110) a respective resultant optical interaction between the each particle and the laser light;analyzing (1112) the respective resultant optical interaction to identify a corresponding particle of the particles as desirable or undesirable based on one or more properties; andbased on the analysis, cause (1114) the corresponding particle to flow into a dedicated flow channel or another flow channel branched from same pathway and adjacent to the dedicated flow channel of the apparatus.
14. The method as claimed in claim 13, wherein when the corresponding particle is identified as undesirable causing the corresponding particle to fall into the dedicated flow channel, wherein the causing comprises:subjecting the corresponding particle to negative di electrophoretic forces in the detection zone;subsequently subjecting the corresponding particle to AC positive dielectrophoretic forces in the deflection zone; andcontemporaneously subjecting the corresponding particle to an AC negative dielectrophoretic pulse provided by a set of electrodes at the mouth of the another flow channel, thereby ensuring the particle successfully flows into the dedicated flow channel.
15. The method as claimed in claim 13, wherein when the corresponding particle is identified as desirable causing the corresponding particle to fall into the another flow channel, wherein causing comprises:allowing the corresponding particle to flow naturally into the another flow channel in the absence of dielectrophoresis forces when axis of the another flow channel is same as axis of the primary microchannel.