Apparatus and method for flow control of single cells or particles - Patents.com

Abstract

Microfluidic devices and methods for flow control of cells or particles in a microfluidic channel are disclosed. The microfluidic device may include a substrate having a microfluidic channel with at least one outlet, a first array of piezoelectric actuators disposed adjacent the outlet to eject a portion of the fluid in the microfluidic channel, and one or more electrode pairs for charging particles (in the fluid) such that the particles flowing through the microfluidic channel can be manipulated by an electric field.

Description

[Technical field]

[0001] This application relates generally to controlling the flow of cells or particles, and more specifically to controlling the flow of cells or particles in microfluidic channels. [Background technology]

[0002] Conventional techniques for flow control of cells or particles in microfluidic devices rely on external flow systems (e.g., using components located outside the microfluidic device). However, such external flow control systems typically do not provide precise control of the fluid dynamics in the microfluidic device for reliable cell capture, localization, and analysis, resulting in more complex and less cost-effective systems. These and other challenges associated with external flow control systems have limited the throughput for processing cells or particles using microfluidic devices. Summary of the Invention

[0003] Described herein are devices and methods for flow control in a microfluidic device or system that may address challenges associated with conventional devices and methods for flow control in a microfluidic device or system.

[0004] Embodiments disclosed herein include hybrid structures (e.g., as described below with reference to Figures 3A-3C) having a glass layer for visualization of biological materials flowing within the microfluidic structure, a polymer layer whose height, width and curvature can be precisely tuned, an integrated piezoelectric layer disposed on a silicon-on-insulator (SOI) layer, and a silicon layer on which electrodes or other MEMS sensors can be fabricated (e.g., with high precision and different aspect ratios to perform a wide variety of sensor functions, either sequentially or in parallel / simultaneous fashion).

[0005] According to some embodiments, a microfluidic device includes a substrate having a microfluidic channel with at least one outlet, a first array of piezoelectric actuators positioned adjacent the outlet for ejecting a portion of fluid in the microfluidic channel, and one or more electrode pairs for charging particles flowing through the microfluidic channel such that the particles may be manipulated by an electric field.

[0006] According to some embodiments, a method for flow control of single cells or particles includes providing a plurality of particles through a microfluidic channel having an outlet, charging the particles such that the particles flowing through the microfluidic channel may be manipulated by an electric field, and ejecting a portion of the fluid in the microfluidic channel using a first array of piezoelectric actuators positioned adjacent to the outlet.

[0007] Thus, the disclosed devices and methods relate to flow control techniques that can be implemented within or as part of a microfluidic device and allow for control of cell or particle flow in a microfluidic flow channel based on electrohydrodynamic (EHD) displacement using piezoelectric actuators and electrodes. Such controlled flow provides reliable cell capture, localization, and analysis. The disclosed devices and methods may replace or complement conventional devices and methods. [Brief description of the drawings]

[0008] For a better understanding of the various embodiments described, please refer to the following detailed description in conjunction with the following drawings, in which like reference numerals refer to corresponding parts throughout the drawings, in which: [Figure 1A] FIG. 1A shows a microfluidic device for flow control of cells or particles in a microfluidic channel, according to some embodiments. [Figure 1B] FIG. 1B shows a microfluidic device for flow control of cells or particles in a microfluidic channel, according to some embodiments. [Diagram 2] FIG. 2 shows a microfluidic device for flow control of cells or particles in a microfluidic channel, according to some embodiments. [Figure 3A] FIG. 3A shows a cross-sectional view of the output area of ​​the microfluidic device shown in FIG. 2 according to some embodiments. [Figure 3B] FIG. 3B shows a cross-sectional view of the fluid channels and outlet regions of the microfluidic device shown in FIG. 2 according to some embodiments. [Figure 3C] FIG. 3C shows a top view of an adhesive layer of a microfluidic device according to some embodiments. [Figure 4] FIG. 4 is a block diagram illustrating electrical components for flow control of cells or particles in a microfluidic channel, according to some embodiments. [Diagram 5] FIG. 5 is a block diagram illustrating a method of flow control of cells or particles in a microfluidic channel according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Reference will be made to the embodiments, which are illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the various described embodiments. However, it will be apparent to those skilled in the art that the various described embodiments may be practiced without these specific details. In other instances, methods, procedures, components, circuits, and networks that are well known to those skilled in the art have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.

[0010] 1A illustrates a microfluidic device 100 according to some embodiments. The device 100 includes a fluidic channel 102 (e.g., a microfluidic channel) formed on a substrate. In some embodiments, the fluidic channel 102 may be formed by bonding a first substrate having a depression, recess, or notch to a second substrate such that the fluidic channel 102 is disposed between the first substrate and the second substrate.

[0011] The fluidic channel 102 has an inlet 103 and an outlet 104, both of which are shown in dashed lines in FIG. 1A. The locations of the inlet 103 and outlet 104 shown with respect to the fluidic channel 102 in FIG. 1A are merely examples. The inlet 103 and outlet 104 may be located at any other location along the length of the fluidic channel 102 or the device 100. In some embodiments, the length L of the fluidic channel 102 (e.g., measured from the inlet 103 to the outlet 104) is in the range of 1 mm to 50 mm. In some embodiments, the width W of the fluidic channel 102 (e.g., a representative portion such as 102-A, which may be the narrowest portion) may be configured based on the size of the particle to be analyzed. For example, for cell measurements, the width W of the fluidic channel 102 is configured according to the size of the cell, such that only a single cell is detected at a time. In some embodiments, the width W of the fluidic channel 102 is in the range of 10 microns to 100 microns (e.g., 50 microns). In some embodiments, the fluidic channel 102 includes one or more portions having a width different from the width W. For example, as shown in FIG. 1A, the fluidic channel 102 may include portions 102-B and 102-C having a (protruding) shape larger than the width W. Similarly, the fluidic channel 102 may include one or more portions having a width smaller than the width W. In some embodiments, the wider the fluidic channel 102, the slower the velocity of the particles flowing through the corresponding portion of that fluidic channel 102 (e.g., if the fluidic channel 102 has a uniform height). Thus, for example, the wider portion 102-C may be used to reduce the velocity of the particles (e.g., immobilize the particles), which allows more time to analyze the particles.

[0012] The device 100 also includes an input region 105 for receiving a sample fluid having particles (e.g., cells) at the inlet port 106 as an input to the device 100, and for providing the sample fluid from the inlet port 106 to the fluidic channel 102 via the inlet 103. The device 100 further includes an output region 107 for collecting at least a portion of the sample fluid from the fluidic channel 102 via the outlet 104, and for ejecting or delivering a portion of the sample fluid via the outlet port 108 (e.g., a nozzle) for further processing or analysis. In some embodiments, the diameter of the outlet port 108 ranges from 60 microns to 120 microns. In some embodiments, the fluidic channel 102 is configured such that the inlet port 106 is the inlet 103 of the fluidic channel 102 and the outlet port 108 is the outlet 104 of the fluidic channel 102.

[0013] In some embodiments, the output region 107 includes a first array of piezoelectric actuators 109 disposed adjacent to the outlet 104 to eject a portion of the fluid in the fluid channel 102. In some embodiments, the first array of piezoelectric actuators 109 includes one or more piezoelectric actuators (e.g., piezoelectric microelectromechanical system (MEMS) actuators). In some embodiments, the first array of piezoelectric actuators 109 includes two or more piezoelectric actuators (e.g., piezoelectric actuators 109-1 and 109-2). In some embodiments, each of the first array of piezoelectric actuators 109 is a piezoelectric element. The piezoelectric elements may have a length equal to 1 mm and a width equal to 0.5 mm. In some embodiments, the device 100 includes an actuation circuit (e.g., actuation circuit 430 described with respect to FIG. 5) electrically coupled to the first array of piezoelectric actuators 109. In some embodiments, in response to application of an electrical signal from an actuation circuit, the first array of piezoelectric actuators 109 generates vibrations that generate displacements as well as acoustic waves, which control the local inertial motion of particles in the fluidic channel 102 in the three-dimensional x, y, and z planes with sub-micron level control. In some embodiments, the first array of piezoelectric actuators 109 induces laminar flow from the inlet 103 toward the outlet 104.

[0014] In some embodiments, the device 100 includes one or more electrode pairs 110 (e.g., one electrode pair). The one or more electrode pairs 110 may be used to charge particles so that particles flowing through the fluidic channel 102 can be manipulated in an electric field. In some embodiments, the distance between the electrode pairs 110 is configured such that only one single cell is manipulated in an electric field at a time. In some embodiments, the device 100 includes a driver circuit (e.g., driver circuit 440 described with respect to FIG. 5) electrically coupled to the one or more electrode pairs 110. In some embodiments, the driver circuit is configured to generate an electrical signal in the megahertz and gigahertz frequency range. In some embodiments, the frequency of the electrical signal provided to the one or more electrode pairs 110 depends on the type or types of particles to be analyzed using the device 100.

[0015] In some embodiments, the output region 107 is divided into multiple output sub-regions (e.g., sub-regions 107-1 to 107-3), as shown in FIG. 1B. In some embodiments, each output sub-region has one outlet port and at least one first array of piezoelectric actuators 109. In this embodiment, each of the different portions of the sample fluid from the outlet 104 (e.g., each portion corresponding to a particular cell or type of cell) is directed to a corresponding output sub-region of the output region 107. Thus, each of the different portions of the sample fluid is collected at and ejected from the corresponding output sub-region. The manner in which the different portions of the sample fluid are directed to each corresponding output sub-region may be accomplished, for example, by vibrations and displacements caused by actuation of the first array of piezoelectric actuators 109 (and / or other piezoelectric actuators implemented within or operably associated with the device 100).

[0016] 2 illustrates a microfluidic device 200 according to some embodiments. The device 200 is similar to the device 100 illustrated in FIG. 1A, except that the device 200 also includes a second array of piezoelectric actuators 202, one or more electrodes (pairs) 204, and / or a third array of piezoelectric actuators 206. In some embodiments, the second array of piezoelectric actuators 202 is disposed adjacent to the inlet 103 to induce laminar flow from the inlet 103 toward the outlet 104. In some embodiments, the second array of piezoelectric actuators 202 is configured for mixing and / or separation of an input sample. In some embodiments, the second array of piezoelectric actuators 202 is disposed between the inlet 103 and the outlet 104. For example, the second array of piezoelectric actuators 202 may be disposed laterally between the inlet 103 and the outlet 104 (e.g., the inlet 103 may be disposed in an upstream region of the microfluidic channel, the outlet 104 may be disposed in a downstream region of the microfluidic channel, and the second array of piezoelectric actuators 202 may be disposed in a midstream region of the microfluidic channel). In some embodiments, the third array of piezoelectric actuators 206 is disposed between the inlet 103 and the outlet 104. Similar to the first array of piezoelectric actuators 109, in some embodiments, the second array of piezoelectric actuators (202) and third array of piezoelectric actuators (206) each include one or more piezoelectric actuators (e.g., piezoelectric microelectromechanical system (MEMS) actuators).

[0017] In some embodiments, in response to application of an electrical signal from the actuation circuit, the second array of piezoelectric actuators 202 generates vibrations that generate acoustic waves and displacements that cause mixing and separation of the sample fluid, controlling localized particle inertial motion to induce laminar flow in the fluidic channel 102. In some configurations, the sample fluid flows through the fluidic channel 102 at a rate of 1 μL / min to 1 mL / min. In some embodiments, when actuated using an appropriate electrical signal from the actuation circuit, the third array of piezoelectric actuators 206 is configured to direct charged particles (manipulated using an electric field generated by the one or more electrode pairs 110 and / or the one or more electrode pairs 204) to specific output sub-regions of the output region 107 (e.g., sub-regions 107-1, 107-2, or 107-3 shown in FIG. 1B).

[0018] In some embodiments, one or more electrode pairs 204 charge the particles so that they can be manipulated by an electric field as they flow through the fluid channel 102 .

[0019] In some embodiments, the one or more electrode pairs 204 detect electrical signals of particles (e.g., cells) flowing through the microfluidic channel 102 adjacent to the one or more electrode pairs 204. In some embodiments, a drive circuit is electrically coupled to the electrodes 204 and configured to generate electrical signals in the megahertz and gigahertz frequency range. In some embodiments, the frequency of the electrical signal provided to the electrode 110 is in the megahertz range and the frequency of the electrical signal provided to the electrode 204 is in the gigahertz range. In some embodiments, the device 200 includes a readout circuit (e.g., readout circuit 450 described with respect to FIG. 4) electrically coupled to one or more electrodes, such as the electrode 110 and the electrode 204. The readout circuit receives electrical signals from the one or more electrodes 110 and 204 and relays the electrical signals (with or without processing, such as filtering) to one or more processors of the device 200 or operably connected to the device 200.

[0020] In some embodiments, one or more electrode pairs 204 provide an electric field to induce motion (e.g., deflection) of a charged particle (e.g., a particle charged by one or more electrode pairs 110). For example, the electric field provided by one or more electrode pairs 204 may induce direct motion of a charged particle by providing a potential difference. As another example, the electric field provided by one or more electrode pairs 204 may be used to control the position, rotation, and / or acceleration of a charged particle. Additionally or alternatively, the electric field provided by one or more electrode pairs 204 may induce electrohydrodynamic flow of a fluid (e.g., if the fluid includes a dielectric medium).

[0021] In some embodiments, each particle may pass near one or more electrode pairs 110 in a period between 0.1 milliseconds and 100 milliseconds. In some embodiments, each particle may pass near one or more electrode pairs 204 in a period between 0.1 milliseconds and 100 milliseconds.

[0022] In some embodiments, the electrode distance between electrode pair 204 , as well as the distance between electrode 110 and electrode 204 , is configured based on one or more types of particles to be analyzed using device 100 .

[0023] In some embodiments, electrode 110 and / or electrode 204 are disposed between the first array of piezoelectric actuators 109 and the second array of piezoelectric actuators 202. In some embodiments, electrode 110 and / or electrode 204 are disposed between the second array of piezoelectric actuators 202 and the third array of piezoelectric actuators 206.

[0024] In some embodiments, particle processing rates in the microfluidic device 200 can be from 100 particles / min to 1 million particles / min.

[0025] 2 also shows that in some embodiments, the electrode pairs 204 are disposed on the same substrate (e.g., substrate 210). In some embodiments, the electrode pairs 204 are disposed on different substrates (e.g., one electrode of the electrode pair 204 is disposed on the lower substrate 210 and the other electrode of the electrode pair 204 is disposed on the upper substrate 212).

[0026] 3A is a cross-sectional view of an output region 107 of a device 200 according to some embodiments. FIG. 3A shows a substrate 302 having a fluidic channel 102. In some embodiments, the substrate 302 includes a first substrate portion 304 and a second substrate portion 306 separated from the first substrate portion 304 such that the fluidic channel 102 is disposed between the first substrate portion 304 and the second substrate portion 306. In some embodiments, the fluidic channel 102 has a height of 10 microns to 1 mm (e.g., 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, 200 microns, 300 microns, 400 microns, 500 microns, 600 microns, 700 microns, 800 microns, 900 microns, or 1 mm, or within a range between any two of the aforementioned values). In some embodiments, the first substrate portion 304 has a thickness of 5 microns to 2 mm (e.g., 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, 200 microns, 300 microns, 400 microns, 500 microns, 600 microns, 700 microns, 800 microns, 900 microns, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, or 2 mm, or within a range between any two of the foregoing values). In some embodiments, the second substrate portion 306 has a thickness of 5 microns to 200 microns (e.g., 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, or 200 microns, or within a range between any two of the foregoing values).

[0027] In some embodiments, the first substrate portion 304 and the second substrate portion 306 are made of different and distinct materials, for example, the first substrate portion is made of glass and the second substrate portion is made of a silicon-on-insulator (SOI) semiconductor structure.

[0028] In some embodiments, the adhesive layer 308 is disposed between the first substrate portion 304 and the second substrate portion 306. In some embodiments, the adhesive layer 308 includes a polymer. In some embodiments, the adhesive layer 308 is comprised of a polymer. In some embodiments, the adhesive layer 308 is adapted and / or arranged to adhere the first substrate portion 304 and the second substrate portion 306 to one another. For example, if the adhesive layer 308 is not included, the first substrate portion (e.g., glass) may not bond to the second substrate portion (e.g., silicon). In some embodiments, the adhesive layer 308 is comprised of a photosensitive material. For example, the photosensitive adhesive layer 308 provides definition, such as width, height, and curvature, of the fluidic channel 102 (e.g., can improve the signal-to-noise ratio (SNR) for single cell sensing). In some embodiments, the adhesive layer 308 is adapted and / or arranged to provide stress relief to the substrate 302 (e.g., to prevent stress cracking when the chip is assembled into a package). In some embodiments, the adhesive layer 308 is cured / solidified (e.g., subjected to multiple stages of curing / solidification). In some embodiments, the adhesive layer 308 is exposed to a temperature above the transition temperature of the adhesive layer (e.g., 150 degrees Celsius), thereby curing the adhesive layer and bonding the first substrate portion 304 (e.g., glass) to the second substrate portion 306 (e.g., silicon). In some embodiments, the adhesive layer 308 is comprised of a liquid or dry film. The adhesive layer 308 may be a negative or positive photoresist. In some embodiments, the adhesive layer 308 is comprised of an epoxy (e.g., bisphenol A) and / or a polyimide, along with a photoinitiator (e.g., added to drive cross-linking based on the wavelength of light).

[0029] In some embodiments, the first substrate portion is 500 microns thick. In some embodiments, the inlet 103 and / or the inlet port 106 are provided on the first substrate portion 304. In some embodiments, the outlet 104 and / or the outlet port 108 are provided on the second substrate portion 306. Furthermore, in some embodiments, the first array 109 of piezoelectric actuators disposed in the output region 107 of the device 200 includes a layer 312 of piezoelectric material disposed on the second substrate portion 306 without overlapping or covering any portion of the outlet 104 and / or the outlet port 108. In some embodiments, the layer 312 of piezoelectric material is disposed between the electrode 310 and the electrode 314, as shown in FIG. 3A. In some embodiments, the layer of piezoelectric material 312 has a thickness of 0.1 microns to 100 microns (e.g., 0.1 microns, 0.5 microns, 1 micron, 2 microns, 5 microns, 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, or 100 microns, or within a range between any two of the foregoing values). In some embodiments, the inlet is provided in the second substrate portion.

[0030] Also shown in Figure 3A is the exit port 108. In some embodiments, the exit port 108 has a diameter of 2 microns to 500 microns (e.g., 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, 200 microns, 300 microns, 400 microns, or 500 microns, or within a range between any two of the foregoing values).

[0031] FIG. 3B illustrates a cross-sectional view of the output region and fluidic channels of the microfluidic device shown in FIG. 2, according to some embodiments. FIG. 3B illustrates a substrate 302 having a fluidic channel 102. The substrate 302 includes a first substrate portion 304 and a second substrate portion 306 bonded via an adhesive layer 308 such that the fluidic channel 102 is provided between the first substrate portion 304 and the second substrate portion 306. The cross-sectional view of the microfluidic channel further illustrates electrodes 310 and 314 and a layer of piezoelectric material 312. In some embodiments, the electrodes 310 and 314 are each composed of a conductive material (e.g., copper, aluminum, or gold). In some embodiments, the layer of piezoelectric material 312 is bonded to one or more contacts (e.g., for providing a current to the piezoelectric material). In some embodiments, the electrodes 310 and / or 314 are bonded to the respective contacts. In some embodiments, the piezoelectric layer 312 is disposed on a silicon-on-insulator (SOI) layer. In some embodiments, the silicon-on-insulator (SOI) layer is connected to one or more contacts. The cross-sectional view of the output region further shows an exit port 108 for the fluidic channel 102.

[0032] FIG. 3C illustrates a top view of an adhesive layer of a microfluidic device, according to some embodiments. The adhesive layer 308 of FIG. 3C includes openings (apertures) 350-1 to 350-8 for electrodes, bond pads, and / or circuitry. The adhesive layer 308 of FIG. 3C further includes an opening 352 for the output region 107 (e.g., outlet port 108), an opening 354 for the input region 105, and an opening 356 for the fluidic channel 102. In some embodiments, the adhesive layer 308 is a polymer layer (e.g., a spin-coated and / or laminated layer). In some embodiments, the adhesive layer 308 has a thickness in the range of 20 microns to 80 microns (e.g., 50 microns). In some embodiments, the adhesive layer 308 forms a fluidic channel between the first substrate portion 304 and the second substrate portion 306. In some embodiments, an opening is formed in the first substrate portion 304 (e.g., to allow access to the bond pads and / or to form an inlet for the microfluidic device). For example, in embodiments in which the first substrate portion 304 is composed of glass, the openings may be formed by laser drilling.

[0033] FIG. 4 is a block diagram illustrating electrical components for flow control of particles in a fluid channel, according to some embodiments. In some embodiments, a device (e.g., device 100 or 200) includes one or more processors 402 and memory 404. In some embodiments, memory 404 includes instructions for execution by one or more processors 402. In some embodiments, the stored instructions include instructions for providing actuation signals to the first array of piezoelectric actuators 109, the second array of piezoelectric actuators 202, and / or the third array of piezoelectric actuators 206. In some embodiments, the actuation signals for the different arrays of piezoelectric actuators may be configured such that each array of piezoelectric actuators generates vibrations at a frequency different from the vibration frequency of another array of piezoelectric actuators. For example, one or more of the first array of piezoelectric actuators 109, the second array of piezoelectric actuators 202, and the third array of piezoelectric actuators 206 may operate at a frequency in the range of 0.5 kHz to 100 kHz, for example, based on a desired flow rate. In some embodiments, the stored instructions include instructions for providing an actuation signal to electrode 110 and / or electrode 204 to charge particles such that the particles flowing through fluid channel 102 can be manipulated by an electric field.

[0034] In some embodiments, the device also includes an electrical interface 406 coupled to the one or more processors 402 and the memory 404 .

[0035] In some embodiments, the device further includes an actuation circuit 430 connected to one or more piezoelectric actuators, such as the first array of piezoelectric actuators 109, the second array of piezoelectric actuators 202, and the third array of piezoelectric actuators 206. The actuation circuit 430 sends an electrical signal to the one or more arrays of piezoelectric actuators 109, 202, 206 to initiate actuation of the one or more arrays of piezoelectric actuators.

[0036] In some embodiments, the device further includes a driver circuit 440 connected to one or more electrodes, such as electrode 110 and electrode 204. The driver circuit 440 sends an electrical signal to the one or more electrodes 110, 204 to generate an electric field to charge particles flowing through the fluid channel 102.

[0037] In some embodiments, the device further includes readout circuitry 450 coupled to one or more electrodes, such as electrode 110 and electrode 204. Readout circuitry 450 receives electrical signals from one or more electrodes 110, 204 and provides the electrical signals (with or without processing) to one or more processors 402 via electrical interface 406.

[0038] FIG. 5 is a flow diagram illustrating a method 500 of flow control of particles in a fluid channel, according to some embodiments.

[0039] The method 500 includes providing 510 a plurality of particles through a microfluidic channel having an outlet. For example, a sample fluid including particles (e.g., cells) is provided to a fluidic channel 102 having an inlet 103 and an outlet 104. In some embodiments, the inlet port 106 is the inlet 103 of the fluidic channel 102 and the outlet port 108 is the outlet 104 of the fluidic channel 102.

[0040] In some embodiments, the method 500 includes inducing 512 a laminar flow from an inlet to an outlet of the microfluidic channel using the first array of piezoelectric actuators or the second array of piezoelectric actuators. For example, the first array of piezoelectric actuators 109 may induce a laminar flow from the inlet 103 to the outlet 104 of the fluidic channel 102. As another example, the second array of piezoelectric actuators 202 disposed adjacent to the inlet 103 may induce a laminar flow from the inlet 103 to the outlet 104 of the fluidic channel 102. The first array of piezoelectric actuators 109 and / or the second array of piezoelectric actuators 202 may be actuated or activated based on an actuation signal from the one or more processors 402.

[0041] In some embodiments, the method 500 includes charging the particles such that the particles flowing through the microfluidic channel can be manipulated by an electric field (514). For example, when actuated, the electrodes 110 and / or the electrodes 204 charge the particles such that the particles flowing through the fluidic channel 102 can be manipulated by an electric field.

[0042] In some embodiments, the method 500 includes providing an actuation signal to one or more electrode pairs to charge particles flowing through the microfluidic channel (516). For example, the one or more processors 402 provide an actuation signal to electrodes 110 and / or electrodes 204 such that particles in the fluidic channel 102 may be manipulated with an electric field.

[0043] In some embodiments, the method 500 includes ejecting (518) a portion of the fluid in the microfluidic channel using a first array of piezoelectric actuators disposed adjacent to the outlet. For example, when actuated or activated, the first array of piezoelectric actuators 109 cause a displacement and vibration to eject a portion of the fluid in the fluidic channel 102 via the outlet port 108. In some embodiments, the method 500 includes providing (520) an actuation signal to the first array of piezoelectric actuators (109), for example from the one or more processors 402.

[0044] The microfluidic devices described herein allow for electrical and / or optical sensing of one or more cells (or other particles). The microfluidic aspects of the device allow for precise flow control (e.g., using electrodes, MEMS sensors, and / or piezoelectric components). In addition, the piezoelectric layer allows for additional integrated functions such as cell sorting (e.g., after a cell signature has been captured). In some embodiments where the substrate is composed of silicon (e.g., second substrate portion 306), electrodes can be deposited in close proximity to each other (e.g., with various aspect ratios) (e.g., allowing for handling of various sample types and sample heterogeneity). Piezoelectric components (e.g., MEMS piezoelectric layers) with exit ports (e.g., nozzles) allow for direct ejection (e.g., jetting) of cells (e.g., after the cells have been processed).

[0045] In light of the above disclosure, certain embodiments are described below.

[0046] (A1) In one aspect, some embodiments include a microfluidic device including: (i) a substrate having a microfluidic channel with at least one outlet; (ii) a first array of piezoelectric actuators positioned adjacent the outlet to eject a portion of fluid in the microfluidic channel; and (iii) one or more electrode pairs for charging particles such that particles flowing through the microfluidic channel may be manipulated by an electric field.

[0047] (A2) In some embodiments of A1, the microfluidic device further comprises a second array of piezoelectric actuators.

[0048] (A3) In some embodiments of A2, the microfluidic channel has an inlet and a second array of piezoelectric actuators is disposed adjacent to the inlet.

[0049] (A4) In some embodiments of A3, the one or more electrode pairs are disposed between the first array of piezoelectric actuators and the second array of piezoelectric actuators.

[0050] (A5) In some embodiments of A3 or A4, the microfluidic device further comprises a third array of piezoelectric actuators disposed between the inlet and the at least one outlet.

[0051] (A6) In some embodiments of A5, the one or more electrode pairs are disposed between the second array of piezoelectric actuators and the third array of piezoelectric actuators.

[0052] (A7) In some embodiments of any of A2 to A6, (i) the microfluidic channel has an inlet, and (ii) a second array of piezoelectric actuators is disposed between the inlet and at least one outlet.

[0053] (A8) In some embodiments of any of A1 to A7, the substrate includes a first substrate portion separated from a second substrate portion, and the microfluidic channel is provided between the first substrate portion and the second substrate portion.

[0054] (A9) In some embodiments of A8, the first substrate portion is made of a first material (e.g., glass) and the second substrate portion is made of a second material (e.g., silicon) that is different from the first material.

[0055] (A10) In some embodiments of A8 or A9, the outlet port of the outlet is provided in the second substrate portion.

[0056] (A11) In some embodiments of any of A8 to A10, the microfluidic channel has an inlet, the inlet being provided in the first substrate portion.

[0057] (A12) In some embodiments of any of A8 to A11, the first array of piezoelectric actuators includes a layer of piezoelectric material disposed on the second substrate portion without overlapping any portion of the outlet port of the outlet.

[0058] (A13) In some embodiments of any of A8 to A12, the microfluidic device further comprises an adhesion layer (e.g., a polymer layer) that adheres the first substrate portion to the second substrate portion (e.g., as shown in Figures 3A to 3C). For example, adhesion layer 308 adheres first substrate portion 304 to second substrate portion 306.

[0059] (A14) In some embodiments of any of A1 to A13, the microfluidic device further includes one or more processors electrically connected to the first array of piezoelectric actuators for providing actuation signals to the first array of piezoelectric actuators.

[0060] (A15) In an embodiment of A14, the one or more processors are configured to provide actuation signals to one or more electrode pairs for charging particles such that particles flowing through the microfluidic channel can be manipulated by an electric field.

[0061] (A16) In some embodiments of any of A1 to A15, the microfluidic device further comprises two or more electrode pairs for providing an electric field such that charged particles flowing through the microfluidic channel can be manipulated based on the electric field.

[0062] (A17) In some embodiments of any of A1 to A16, the first portion of the microfluidic channel has a first width and the second portion of the microfluidic channel has a second width that is greater than the first width.

[0063] (B1) In another aspect, some embodiments include a method that includes: (i) providing a plurality of particles through a microfluidic channel having an outlet; (ii) charging the particles such that the particles flowing through the microfluidic channel may be manipulated by an electric field; and (iii) ejecting a portion of the fluid in the microfluidic channel using a first array of piezoelectric actuators positioned adjacent to the outlet.

[0064] (B2) In some embodiments of B1, the method further comprises inducing laminar flow from the inlet to the outlet of the microfluidic channel using a first array of piezoelectric actuators.

[0065] (B3) In some embodiments of B1 or B2, the method further includes providing an actuation signal to the first array of piezoelectric actuators.

[0066] (B4) In some embodiments of any of B1 to B3, the method further includes providing an actuation signal to one or more electrode pairs to charge the particles such that the particles flowing through the microfluidic channel can be manipulated by an electric field.

[0067] (B5) In some embodiments of B1 to B3, the method further includes providing an actuation signal to two or more electrode pairs to charge the particles such that the particles flowing through the microfluidic channel can be manipulated by an electric field.

[0068] (C1) In another aspect, some embodiments include a microfluidic device including: (i) a first substrate comprised of a first material; (ii) a second substrate comprised of a second material different from the first material; and (iii) an adhesive layer bonding the first substrate and the second substrate, the adhesive layer providing a microfluidic channel having at least one outlet.

[0069] (C2) In some embodiments of C1, the microfluidic device further comprises a first array of piezoelectric actuators disposed adjacent to an outlet for ejecting a portion of the fluid in the microfluidic channel.

[0070] (C3) In some embodiments of C1 or C2, the microfluidic device further comprises one or more electrode pairs for charging particles such that particles flowing through the microfluidic channel can be manipulated by an electric field.

[0071] (C4) In some embodiments of any of C1 to C3, the first material is glass and the second material is silicon. In some embodiments, the second material is silicon-on-insulator (SOI).

[0072] (C5) In some embodiments of any of C1 to C4, the adhesive layer is comprised of a polymeric material. In some embodiments, the polymeric material is a photosensitive material.

[0073] It will also be understood that although terms such as first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first array can be referred to as a second array, and similarly, a second array can be referred to as a first array, without departing from the scope of various described embodiments. Although a first array and a second array are both arrays, they are not the same array.

[0074] The terminology used in the description of the embodiments herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims. As used in the description and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly dictates otherwise. It will also be understood that the term "and / or" as used herein refers to and includes any and all possible combinations of one or more of the associated listed items. It will also be understood that the terms "comprises" and / or "comprising" as used herein specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0075] For purposes of explanation, the foregoing description has been described with reference to specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the scope of the claims to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings. The embodiments have been selected and described in order to best explain the principles of the various described embodiments and their practical applications, thereby enabling others skilled in the art to best utilize the principles and various modifications suited to the particular applications contemplated.

Claims

1. a substrate comprising a microfluidic channel having at least one outlet; a first array of piezoelectric actuators disposed adjacent the outlet for ejecting a portion of fluid in the microfluidic channel; and one or more electrode pairs for charging particles flowing through a microfluidic channel such that the particles can be manipulated by an electric field.

2. The microfluidic device of claim 1 , further comprising a second array of piezoelectric actuators.

3. the microfluidic channel has an inlet; The microfluidic device of claim 2 , wherein the second array of piezoelectric actuators is disposed between the inlet and the at least one outlet.

4. The microfluidic device of claim 2 , wherein the microfluidic channel has an inlet, and the second array of piezoelectric actuators is positioned adjacent to the inlet.

5. The microfluidic device of claim 4 , wherein the one or more electrode pairs are disposed between the first array of piezoelectric actuators and the second array of piezoelectric actuators.

6. The microfluidic device of claim 4 , further comprising a third array of piezoelectric actuators disposed between the inlet and the at least one outlet.

7. The microfluidic device of claim 6 , wherein the one or more electrode pairs are disposed between the second array of piezoelectric actuators and the third array of piezoelectric actuators.

8. 2. The microfluidic device of claim 1, wherein the substrate comprises a first substrate portion separated from a second substrate portion, the microfluidic channel being disposed between the first substrate portion and the second substrate portion.

9. The microfluidic device of claim 8 , wherein the first substrate portion is made of a first material and the second substrate portion is made of a second material different from the first material.

10. The microfluidic device of claim 8 , wherein an outlet port of the outlet is provided in the second substrate portion.

11. the microfluidic channel has an inlet; The microfluidic device of claim 8 , wherein the inlet is provided in the first substrate portion.

12. 9. The microfluidic device of claim 8, wherein the first array of piezoelectric actuators comprises a layer of piezoelectric material disposed on the second substrate portion without overlapping any portion of the outlet ports of the outlets.

13. 9. The microfluidic device of claim 8, further comprising an adhesive layer adhering the first substrate portion to the second substrate portion, the adhesive layer further providing at least a portion of the microfluidic channel.

14. 10. The microfluidic device of claim 1, further comprising one or more processors electrically coupled to the first array of piezoelectric actuators for providing actuation signals to the first array of piezoelectric actuators.

15. 15. The microfluidic device of claim 14, wherein the one or more processors are configured to provide actuation signals to one or more electrode pairs for charging particles flowing through a microfluidic channel such that the particles can be manipulated by an electric field.

16. providing a plurality of particles through a microfluidic channel having an outlet; charging particles flowing through a microfluidic channel such that said particles can be manipulated by an electric field; and ejecting a portion of fluid in the microfluidic channel using a first array of piezoelectric actuators positioned adjacent to the outlet.

17. 17. The method of claim 16, further comprising inducing laminar flow from an inlet to an outlet of the microfluidic channel using the first array of piezoelectric actuators.

18. providing actuation signals to a first array of said piezoelectric actuators; or 17. The method of claim 16, further comprising at least one of providing an actuation signal to one or more electrode pairs for charging particles flowing through a microfluidic channel such that the particles can be manipulated by an electric field.

19. 17. The method of claim 16, further comprising providing an actuation signal to two or more electrode pairs for charging particles flowing through the microfluidic channel such that the particles can be manipulated by an electric field.

20. 1. A microfluidic device comprising: a first substrate constructed from a first material; a second substrate composed of a second material different from the first material; A microfluidic device comprising: an adhesive layer bonding the first substrate and the second substrate, the adhesive layer defining a microfluidic channel having at least one outlet.

21. 21. The microfluidic device of claim 20, further comprising a first array of piezoelectric actuators positioned adjacent the outlet for ejecting a portion of fluid in the microfluidic channel.

22. 21. The microfluidic device of claim 20, further comprising one or more electrode pairs for charging particles flowing through the microfluidic channel such that the particles can be manipulated by an electric field.

23. 21. The microfluidic device of claim 20, wherein the first material is glass and the second material is silicon.

24. The microfluidic device of claim 20 , wherein the adhesion layer is composed of a polymeric material.

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