Device for carrying out direction control and separation on charged particles in electrolyte

Abstract

The invention discloses a device for performing direction control and separation on charged particles in electrolyte, which comprises a microfluid channel, the microfluid channel is provided with a sample inlet port and a sample outlet port, a fluid flows from the sample inlet port to the sample outlet port at a speed v0, a separation chamber is formed in the microfluid channel, the fluid contains the charged particles, and the separation chamber is communicated with the sample inlet port and the sample outlet port. Charged particles are separated in the separation chamber; the number of the electrodes in each group of electrodes is the same or different, each electrode is in contact with the fluid, a pseudocapacitor and / or a double-layer capacitor are / is formed on the contact interface of the electrode and the fluid, the electrodes are arranged in the microfluid channel in parallel, and a certain angle can be formed between the arrangement direction and the flowing direction of the fluid; a plurality of conductor leads; and each driving power supply is connected with one group of electrodes, the driving power supplies generate periodic voltage or current excitation, and the voltage excitation or the current excitation output by the driving power supplies in an output period is in a changing state.

Description

Technical Field

[0001] The invention relates to the field of charged particle motion control, and in particular to a device for controlling the direction and separating charged particles in an electrolyte. Background Art

[0002] Charged particles in a liquid or colloid are forced to move under the action of an electric field. By introducing an electric current into a liquid or colloid electrolyte to form an electric field, the fluid or charged particles in the fluid can be manipulated and controlled.

[0003] At present, the main method of introducing current into the fluid is to use a conductor electrode represented by a graphite electrode, an alloy electrode or some solid metals such as gold, platinum, etc. The electrode is usually placed perpendicular to the direction of fluid movement, and the displacement difference of the charged particles in the direction of the electric field is controlled to separate different charged particles. A membrane-like structure is used between the electrode area and the separation chamber to increase the resistance to fluid movement, thereby preventing the fluid, especially the particles in the fluid, from flowing to the electrode chamber. In microfluidic chips, the application voltage loss of such a membrane-like structure is large and the voltage efficiency is low. At the same time, the working voltage is too large, which then causes Joule heat, affecting the uniformity of the electric field, the stability of the electrolyte solution, and the movement of the charged particles therein. In addition, during the working process of the conductor electrode, the carriers in the electrolyte solution are ions, while the carriers in the conductor are electrons. Therefore, at the interface of the electrode-fluid, there is an inevitable electrochemical reaction due to the charge transfer of the carriers. The bubbles generated by the electrochemical reaction cannot be eliminated during the working process of the electrode, and local bubbles are an important reason for the failure of various microfluidic chips.

[0004] Figure 1 Schematic diagram of a traditional free-flow electrophoresis device, 301 is a charged particle in a microfluid, which may be a solid, gas or liquid including cells, bacteria, microorganisms, proteins, vesicles, etc., 302 is a common conductor electrode, 303 is a membrane-like material or microstructure, which is used to isolate the solution in the separation chamber 305 and the electrode chamber 306, and ensure a stable electric field in the separation chamber 305. 304 is the outer wall of the microfluidic channel, in which the fluid moves at a speed v, and the electric field is perpendicular to the direction of fluid movement. When the fluid flows through the separation chamber 305, the charged particles in the fluid have different speeds in the electric field due to their different properties such as charge and mass, resulting in differences in their offsets, thereby separating different types of charged particles. When an ordinary electrode is connected to an electrical signal, an electrolytic reaction occurs at the electrode interface, generating bubbles, and the electrophoresis system has low stability. In addition, due to the presence of a membrane-like structure, the actual electric field intensity applied to the separation chamber 305 is small, that is, the voltage efficiency is low.

[0005] In US Patent US6890409, by adopting a method of separating the electrode part from the microchannel, the entry of air bubbles into the microfluid is avoided. This solution uses an additional channel to separate the air bubbles generated by the electrodes from the microfluidic channel and cannot be applied in a closed fluid channel.

[0006] Chinese Patent CN200455328C discloses a method of electropermeabilizing cell walls using a pulsed electric field provided by a waveform generator and electropermeabilizing cell walls using the electric field between multiple parallel electrodes. By reciprocating current excitation between the electrodes, an alternating electric field is generated to weaken the electrochemical reaction at the electrode-fluid interface. This solution cannot avoid the carrier transformation process between the electrode and the electrolyte, that is, the electrolysis reaction, and the specific application scope and the effect of the solution are greatly limited.

[0007] Chinese Patent CN108885189A discloses a device for separating and analyzing samples by microfluidic electrophoresis. The patent places the electrodes in the electrolyte channels on both sides and sets up a conductive channel array between the electrolyte channels and the separation channel. These channels provide a uniform electric field distribution while generating a high hydrodynamic resistance. The products of the electrolysis reaction flow out through the electrolyte channels where the electrodes are located. In this solution, the distance between the electrodes and the separation channel is too large, the voltage actually used for separation is small, and the voltage efficiency is low.

[0008] Chinese Patent CN1181337C discloses a method of controlling and transporting charged particles by a traveling wave electric field. This solution uses a linear parallel electrode array and applies electrical signals with a certain phase difference to the electrodes respectively to generate a traveling wave signal above the electrodes. By controlling the direction of the traveling wave signal, two types of charged particles move forward and backward respectively to separate the two types of charged particles. This solution has extremely low separation efficiency, and the problem of air bubbles caused by the electrolysis reaction at the electrode-electrolyte interface cannot be solved, making it difficult to be practically applied.

[0009] In summary, the deficiencies of the core existing solutions are as follows:

[0010] 1. Ordinary electrodes have electrolysis reactions at the electrode interface and the resulting adverse factors, which are greatly limited in the application of microchannel systems. For example, driving ordinary electrodes with high-frequency traveling waves is a temporary solution with limited use scenarios and difficult to be widely applied;

[0011] 2. The common electrode placement method is a fixed electrode device with the electric field perpendicular to the direction of fluid movement. The distance between the electrodes is large, and the membrane-like structure between the electrodes and the separation chamber causes a certain voltage loss. The voltage actually applied to separation is low, resulting in extremely low voltage efficiency of the electric field, low separation efficiency, and severely limited application scenarios;

[0012] 3. Free-flow zone electrophoresis uses two electrodes to provide a fixed electric field. High voltage can cause problems such as Joule heating, resulting in low separation efficiency and inability to be applied on a large scale. Summary of the Invention

[0013] The present invention provides a device for controlling the direction and separating charged particles in an electrolyte to solve the technical problems existing in the above-mentioned prior art.

[0014] To achieve the above object, the present invention provides a device for controlling the direction and separating charged particles in an electrolyte, which includes:

[0015] A microfluidic channel having a plurality of ports including one or more sample injection ports and one or more sample output ports, for fluid to flow from the sample injection port to the sample output port at a speed v0. A separation chamber is formed inside the microfluidic channel, and the fluid contains charged particles, and the charged particles are separated inside the separation chamber;

[0016] Two or more groups of electrodes, where the number of electrodes in each group is the same or different. Each electrode is in contact with the fluid and forms a pseudocapacitance and / or a double-layer capacitance at the interface where the electrode contacts the fluid. The electrodes are arranged in parallel inside the microfluidic channel and there is a certain angle between the arrangement direction and the fluid flow direction;

[0017] A plurality of conductor leads; and

[0018] Two or more driving power supplies, each driving power supply is connected to one group of electrodes. The driving power supply generates a periodic voltage or current excitation, and the voltage excitation or current excitation output by the driving power supply within one output cycle is in a changing state;

[0019] Each electrode continuously rotates for charging and discharging, forming a traveling wave electric field with a periodically changing amplitude in the microfluidic channel. The electric field force received by the charged particles in the traveling wave electric field is decomposed into a first component and a second component perpendicular to each other. The first component is parallel to the fluid movement direction and drives the charged particles to move along the first component direction, and the second component is perpendicular to the fluid movement direction and separates the charged particles according to different charge-to-mass ratios. The expression of the traveling wave electric field E is:

[0020]

[0021] where A is the maximum amplitude of the traveling wave electric field, T0 is the period of the traveling wave electric field, θ is the angle between the parallel electrodes and the fluid flow direction, c is the phase of the traveling wave electric field. Taking the lower left corner position of the leftmost first electrode as the origin, taking the fluid flow direction as the x-axis, and taking the direction obtained by rotating the x-axis counterclockwise by 90 degrees as the y-axis, x and y are the abscissa and ordinate of the point in the traveling wave electric field respectively, and S0 is the period of the electric field strength with respect to the coordinates (x, y).

[0022] The traveling-wave electric field E moves at a preset traveling speed of the traveling wave.

[0023] In one embodiment of the present invention, the charged particles are solids, gases, liquids or bubbles including cells, bacteria, microorganisms, proteins, vesicles, and / or

[0024] The charged particles carry positive or negative charges.

[0025] In one embodiment of the present invention, the period, frequency, and the output voltage and / or current waveform of the driving power supply are all adjustable, and

[0026] The amplitude, positive-negative amplitude ratio, and traveling speed of the traveling-wave electric field are all adjustable.

[0027] In one embodiment of the present invention, within one or more cycles of the traveling-wave electric field, the total input current on each electrode is equal to the total output current, that is, the net input current and net output current on each electrode are both zero; or

[0028] The total input charge and total output charge on each electrode are always less than the total charge capacity of the electrode.

[0029] In one embodiment of the present invention, where d is the horizontal distance between adjacent electrodes.

[0030] In one embodiment of the present invention, θ is between 0° and 90°.

[0031] The device provided by the present invention for direction control and separation of charged particles in an electrolyte has the following beneficial technical effects:

[0032] 1. Compared with traditional electrodes

[0033] ① It solves the electrolysis reaction of the electrodes, eliminates the generation of bubbles,

[0034] ② It solves the passivation problem of the electrodes after long-term use, extends the service life of the electrodes,

[0035] ③ It solves the problem of charge capacity limitation,

[0036] ④ It solves the electrode toxicity caused by the adsorption of microparticles in the fluid, and greatly extends the long-cycle stability of the electrodes.

[0037] 2. Compared with the existing electrode solutions

[0038] ① High voltage efficiency,

[0039] ② Fast speed of manipulating charged particles and high separation efficiency,

[0040] ③ It can drive nano charged particles and provide a very high current driving force at the micro and nano scales,

[0041] ④ It can precisely control the movement of charged particles.

[0042] ⑤ It can work stably for a long time, greatly broadening the application scenarios.

[0043] In summary, in the microchannel fluid system, the device provided by the present invention for controlling the direction and separating charged particles in the electrolyte has incomparable advantages over the existing solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0045] Figure 1 FIG. 17 is a schematic diagram of a traditional free-flow electrophoresis device;

[0046] Figure 2a FIG. 21 is a schematic diagram of a new traveling-wave electrophoresis separation device;

[0047] Figure 2b FIG. Figure 2a is a sectional view taken along line A-AA in FIG.

[0048] Figure 3a FIG. 31 is a schematic diagram of a device for controlling the direction and separating charged particles in the electrolyte according to an embodiment of the present invention;

[0049] Figure 3b FIG. Figure 3a is a schematic diagram of the output voltage of the driving power supply in FIG.

[0050] Figure 4a FIG. 41 is a schematic diagram of a device for controlling the direction and separating charged particles in the electrolyte according to another embodiment of the present invention;

[0051] Figure 4b FIG. Figure 4a is a sectional view taken along line A-AA in FIG.

[0052] Figure 4c FIG. Figure 4a is a schematic diagram of the output voltage of the driving power supply in FIG.

[0053] Figure 4d FIG. Figure 4a is a schematic diagram of the running track of charged particles in FIG. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0055] Figure 2a It is a schematic diagram of a novel traveling-wave electrophoresis separation device. Figure 2b is Figure 2a The sectional view of A-AA in, as Figure 2a 、 2b shown, 301 is a charged particle in the microfluid, and the charged particle may be a solid, gas or liquid including cells, bacteria, microorganisms, proteins, vesicles, etc. 304 is the outer wall of the microfluid channel, 305 is an electrode using a double-layer capacitor / pseudo-capacitor. The problem of generating bubbles is solved by using the double-layer capacitor / pseudo-capacitor structure. The electrode is in direct contact with the medium where the charged particle is located, and the electric field generated by the electrode directly acts on the charged particle, improving the voltage efficiency and having a high separation efficiency of the charged particle. The electrode is placed obliquely, and the electric field between the electrodes has a certain angle with the fluid movement direction. The generated electric field force can be decomposed into a direction parallel to the fluid and a direction perpendicular to the fluid. The electric field parallel to the fluid is used to propel the charged particle forward, and the electric field perpendicular to the fluid is used to precisely screen and distinguish charged particles with different charge-mass ratios.

[0056] Figure 2a 、 2b In, there are certain charged particles distributed in the fluid. The charged particle can be a solid, liquid, or bubble with a size ranging from a few nanometers to dozens of micrometers. The charge carried can be a positive charge or a negative charge. When these charged particles are acted on by an electric field force, they will generate a movement relative to the fluid where they are located.

[0057] In the above Figure 2a 、 2b On the basis of, the present invention provides a device for controlling the direction and separating charged particles in an electrolyte. As Figure 3a is a schematic diagram of a device for controlling the direction and separating charged particles in an electrolyte according to an embodiment of the present invention, which includes:

[0058] Microfluidic channel 1, the microfluidic channel has a sampling port 11 and a sample outlet port 12, for fluid to flow from the sampling port 11 towards the sample outlet port 12 at a speed v0. A separation chamber is formed inside the microfluidic channel 1. There is no physical isolation between the separation chamber and the electrode chamber in the present invention. The internal space of the microfluidic channel 1 can all be regarded as the separation chamber. The fluid contains charged particles, and the charged particles are separated inside the separation chamber. The charged particles can be solids, gases, liquids or bubbles including cells, bacteria, microorganisms, proteins, vesicles, etc., and / or the charged particles carry positive or negative charges;

[0059] Two or more groups of electrodes 2, the number of electrodes in each group can be the same or different. In this embodiment, there are two groups of electrodes. The first group of electrodes is connected to V1 and the number is two, and the second group of electrodes is connected to V2 and the number is one. Each electrode is in contact with the fluid and forms a pseudocapacitance and / or a double-layer capacitance at the interface where the electrode contacts the fluid. The electrodes are arranged in parallel inside the microfluidic channel and there can be a certain angle between the arrangement direction and the fluid flow direction. In the present invention, through the pseudocapacitance and the double-layer capacitance, the electrochemical reaction at the electrode interface is avoided. The double-layer capacitance realizes charge storage through the double layer generated by the adsorption of charged ions in the electrolyte on the net charge of the electrode surface, and there is no redox process involved, fundamentally eliminating the generation of bubbles. The pseudocapacitance stores and releases electrical energy through the continuous, reversible, and phase-change-free Faraday reaction that occurs at the electrode material under a specific potential. No bubbles will be generated at the electrode interface, and it has a larger charge capacity and long cycle stability. By combining the double-layer capacitance and the pseudocapacitance, a certain double-layer capacitance interface is obtained by arranging a larger surface area and surface treatment of the pseudocapacitance electrode, which can further increase the capacitance and improve the electrode efficiency;

[0060] Multiple conductor leads 3; and

[0061] Two or more driving power supplies 4 (V1 / V2), each driving power supply is connected to one group of electrodes. The driving power supply generates a periodic voltage or current excitation, and the voltage excitation or current excitation output by the driving power supply within one output cycle is in a changing state. The period, frequency, and the voltage and / or current waveforms output by the driving power supply 4 are all adjustable, and the amplitude, positive and negative amplitude ratio, and traveling wave moving speed of the traveling wave electric field are all adjustable;

[0062] Each electrode is continuously rotated for charging and discharging, forming a traveling wave electric field with a periodically changing amplitude in the microfluidic channel 1. The electric field force received by the charged particles in the traveling wave electric field is decomposed into a first component and a second component perpendicular to each other. The first component is parallel to the fluid movement direction and drives the charged particles to move along the first component direction, and the second component is perpendicular to the fluid movement direction and separates the charged particles according to different charge-mass ratios. The expression of the traveling wave electric field E is:

[0063]

[0064] Wherein, A is the maximum amplitude of the traveling-wave electric field, T0 is the period of the traveling-wave electric field, θ is the angle between the parallel electrodes and the fluid flow direction, c is the phase of the traveling-wave electric field. As shown in Figure 3, taking the position of the lower left corner of the leftmost first electrode as the origin, the fluid flow direction as the x-axis, and the direction rotated 90 degrees counterclockwise from the x-axis as the y-axis, x and y are respectively the abscissa and ordinate of the midpoint of the traveling-wave electric field, and S0 is the period of the electric field strength with respect to the coordinates (x, y).

[0065] The traveling-wave electric field E moves at a preset traveling speed of the traveling wave.

[0066] As Figure 3a shown, in the present invention, the electrodes are placed inside the separation chamber, and the traveling-wave electric field is directly used to separate charged particles, reducing voltage loss and improving the voltage efficiency of the device. The electrodes are placed below and / or above the separation chamber, and there may be a certain angle between the electrodes and the x-axis (the x-axis is defined as the direction of fluid movement). The electric field generated by the electrodes can directly act on the charged particles, without voltage loss, improving the efficiency of the electrodes. The charged particles in the fluid will generate a movement parallel to the direction of the electric field under the action of the electric field, and this movement is superimposed on the fluid movement to form the movement of the charged particles. Due to the different charges and masses of different charged particles, there are differences in the position displacements on the y-axis (the y-axis is defined as the direction perpendicular to the fluid movement direction), thereby realizing the sorting of different particles in the medium.

[0067] The traveling-wave electric field refers to an electric field with a directional migration in space formed by multiple electrodes performing periodic rotation of charge and discharge in time during the working process. This electric field moves forward or backward according to the voltage change, that is, the electric field between every two electrodes moves forward or backward with time. The traveling-wave electric field is periodic in time and space, that is, the electric field directions at different positions at different times alternate periodically between the positive and negative directions. When the charged particle is in the positive electric field, it will move upward to the right, and when it is in the negative electric field, it will move downward to the right. Overall, the movement trajectory of the charged particle fluctuates in a certain waveform and moves upward with an offset. The mobilities and velocities of charged particles with different charge-to-mass ratios in the electric field will have certain differences in their movement trajectories in the electric field. By controlling factors such as the speed, frequency, and phase of the traveling-wave electric field, the offset of specific particles when leaving the electric field is cancelled out, and the charged particles entering the electric field at different times are at the same position when leaving the electric field, and the trajectories of the charged particles tend to be a straight line. Other charged particles leave the electric field fluctuating in a certain waveform, separating the specific charged particles and completing the enrichment. That is, by adjusting factors such as the angle of the electrodes, the magnitude and period of the electric field, the target charged particles can finally be separated in the form of a straight line or an approximate straight line (concentrated in a specific area) at certain moments.

[0068] During the operation of the electrode, a traveling-wave electric field is realized in time by alternately charging and discharging the electrode, and charged particles in the fluid are controlled. The electrodes work alternately in the anode mode and the cathode mode at different times, ensuring that the charge output of each electrode does not exceed its charge capacity. The carrier transformation is completed inside the electrode, eliminating bubbles generated by electrolysis reactions and Joule heat, etc. This greatly improves the voltage efficiency of the electrode, reduces the separation time, and improves the separation efficiency.

[0069] The traveling-wave electric field E moves forward or backward in the form of a sine wave in the microfluidic channel 1 and is periodically distributed in terms of time t and x, y. The moving direction and speed of the traveling-wave electric field E are fixed. Assuming the traveling-wave electric field E is stationary, the charged particles have to pass through the forward electric field and the reverse electric field completely during the movement. In Figure 3a the device shown, there are two groups of electrodes in the microfluidic channel 1, and the two groups of electrodes are placed parallel and staggered with each other. They are respectively connected to the driving power supply V1 and the driving power supply V2. Figure 3b For Figure 3a the schematic diagram of the output voltage of the driving power supply in, when V1 and V2 are not equal, there will be an alternating electric field with equal magnitude and opposite directions between the two groups of electrodes, which are respectively Ep = (V2 - V1) / (d*sin(θ)) and En = (V1 - V2) / (d*sin(θ)). By periodically charging and discharging the electrodes, a migration-asymmetric traveling-wave electric field is formed in space, solving the problem of capacitance charge limitation, increasing the voltage threshold, and improving the separation efficiency.

[0070] The charged particle q in the microfluidic channel 1 is subjected to an electrostatic force in Ep / En, generating a migration velocity v that is proportional to the electric field strength and the charge-to-mass ratio of the charged particle. q+ / v q- . There is a deflection angle θ between the parallel electrodes and the fluid velocity. This electrostatic force can be decomposed into v parallel to the fluid velocity v0, that is, in the x direction, x+ , and v perpendicular to the fluid velocity v0, that is, in the y direction. y+ . In the reverse electric field, the corresponding ones are v x- and v y- .

[0071] Assume the fluid moves at a constant speed and the flow velocity v0 is constant. In the action interval of Ep, the horizontal movement speed of the charged particle is v0 - v x+ , the direction is to the right, and the vertical movement speed is v y+ , the direction is upward. Therefore, the combined movement direction of the charged particle is in the first quadrant, that is, moving right-upward. Due to the inclined placement of the electrodes, the horizontal movement distance of the charged particle in the Ep interval is greater than d, and the time t1 > d / (v0 - v x+ ). In the action interval of En, the horizontal movement speed of the charged particle is v0 + v x-, in the right direction, and the vertical moving speed is v y- , in the downward direction. Therefore, the combined moving direction of the charged particles is in the fourth quadrant, that is, moving right downward. Since the electrodes are inclined, the horizontal moving distance of the charged particles in the Ep interval is less than d, and the time t2 < d / (v0 + v x- ), from which it is inferred that t1 > d / (v0 - v x+ ) > d / (v0 + v x- ) > t2. v y+ and v y- are equal in magnitude and opposite in direction. After the charged particles pass through a pair of positive and negative electric field action intervals Ep and En, due to the different action times, v y+ * t1 > v y- * t2, that is, the vertical migration distance in the Ep interval is greater than the vertical migration distance in the En interval, and the charged particles move vertically in the electric field. This moving speed is determined by parameters such as the intensity of the electric field Ep / En, the charge-mass ratio of the charged particles, the liquid viscosity coefficient, the electrode deflection angle θ, and the flow velocity v0, the electrode distance d, etc.

[0072] After charged particles with different charge-mass ratios pass through a pair of electric field regions, a controllable vertical movement is generated. The movement amplitude has nothing to do with the order of the Ep / En action. Therefore, by periodically swapping the order of Ep / En, that is, periodically swapping the voltages of V1 / V2, the electrodes only need to provide a reciprocating driving current to the fluid. Under the condition that the electric field amplitude remains unchanged, the charge capacity load requirement of the electrodes can be reduced by reducing the swapping period, and the typical period is set to be not less than v0 / (2 * d).

[0073] By adjusting the voltage amplitude of V1 / V2, controlling the magnitudes of Ep / En and the specific electric field waveform, charged particles with different charge-mass ratios in the medium can be precisely controlled.

[0074] Figure 4a is a schematic diagram of a device for controlling the direction and separating charged particles in an electrolyte according to another embodiment of the present invention, as shown in Figure 4a , 4b . 301 is the outer wall of the microfluidic channel, 302 and 303 are electrodes, 304 are charged particles, 306 are conductor leads, V1 to V4 are driving power supplies, the fluid moves at a certain fixed speed v, and the electrodes 302 and 303 are alternately charged and discharged. The included angle between the direction of the electric field E between the electrodes and the fluid moving speed v is greater than zero.

[0075] Figure 4a Four electrodes are used as a group. By applying electrical signals with a certain phase difference to the four electrodes respectively, a traveling wave electric field is generated in the fluid. Figure 4c is Figure 4a the schematic diagram of the output voltage of the driving power supply in, and the expression of the generated traveling wave electric field is It indicates that the electric field presents a periodic distribution in the time t and the x, y directions. k = tanθ, where θ is the angle between the parallel electrodes and the horizontal direction, A is the amplitude of the electric field, T0 is the period of the electric field intensity with respect to time t, S0 is the period of the electric field intensity with respect to x, y, and c is the phase. θ can be between 0° and 90°, and by adjusting θ, the movement of charged particles can be controlled. The movement of charged particles in the traveling wave electric field will pass through many sets of positive and negative alternating electric fields, generating an offset perpendicular to the flow channel direction.

[0076] Figure 4a The setting methods of the x-axis and y-axis in Figure 3a are the same. The movement speed of the charged particle in the x direction is: x′(t) = -m * E(t, x, y) * sinθ + v0; the movement speed in the y direction is: y′(t) = m * E(t, x, y) * cosθ. Substituting the above electric field E can solve the movement trajectory of the charged particle, and the displacement of the charged particle in the y direction will fluctuate and shift upward with the increase of time. Since the general solution of this differential equation is not easy to obtain, matlab is used to find its numerical solution.

[0077] Figure 4d is the top view of the electric field. The dotted line in the figure represents the movement trajectory of the charged particle. The charged particle will fluctuate and shift upward in the electric field with the increase of time, and the offset size is affected by the frequency of the electric field and the phase-related parameters. Charged particles entering the electric field at different time points differ by a time t0, and the movement trajectory equations of the charged particles will differ by a phase. By adjusting factors such as the angle and speed of the traveling wave electric field, the offset in the y direction caused by the phase at the end position of the electric field can be offset. The charged particle is at the same position when leaving the electric field, that is, it leaves the electric field in a form approaching a straight line, better enriching specific charged particles. The longitudinal displacement deviation c of other charged particles, and the positions of charged particles entering at different times will fluctuate up and down when leaving the electric field, showing a fluctuating form. Different speeds and movement trajectories result in different displacement distances of different charged particles in the flow channel, so they are separated from specific charged particles when leaving the electric field, completing the separation of charged particles in the medium.

[0078] For charged particles with different charge-to-mass ratios, their movement speeds and movement trajectories are different. By adjusting the input position of the charged particles and the phase of the traveling wave electric field, controlling the movement of different charged particles and the timing when the displacement deviation of specific charged particles disappears, the displacements of different charged particles in the y direction are different, so as to complete the separation of charged particles.

[0079] In an embodiment of the present invention, within one or more periods of the traveling wave electric field, the total input current on each electrode is equal to the total output current, that is, the net input current and net output current on each electrode are both zero; or

[0080] The total input charge and the total output charge on each electrode are always less than the charge capacity of the electrode.

[0081] In one embodiment of the present invention, where d is the horizontal distance between adjacent electrodes.

[0082] In one embodiment of the present invention, θ is between 0° and 90°.

[0083] The device provided by the present invention for controlling the direction and separating charged particles in the electrolyte has the following beneficial technical effects:

[0084] 1. Compared with traditional electrodes

[0085] ① It solves the electrolysis reaction of the electrode and eliminates the generation of bubbles.

[0086] ② It solves the passivation problem of the electrode after long-term use and extends the service life of the electrode.

[0087] ③ It solves the problem of charge capacity limitation.

[0088] ④ It solves the electrode toxicity caused by the adsorption of particles in the fluid and greatly extends the long-term cycling stability of the electrode.

[0089] 2. Compared with existing electrode solutions

[0090] ① High voltage efficiency.

[0091] ② Fast speed of controlling charged particles and high separation efficiency.

[0092] ③ It can drive nanoparticles to carry electrons and provide a very high current driving force at the micro and nano scales.

[0093] ④ It can precisely control the movement of charged particles.

[0094] ⑤ It can work stably for a long time and greatly broaden the application scenarios.

[0095] In summary, in the microchannel fluid system, the device provided by the present invention for controlling the direction and separating charged particles in the electrolyte has incomparable advantages over existing solutions.

[0096] Those of ordinary skill in the art can understand that the drawings are only schematic diagrams of one embodiment, and the modules or processes in the drawings are not necessarily essential for implementing the present invention.

[0097] Those of ordinary skill in the art can understand that the modules in the device in the embodiment can be distributed in the device of the embodiment according to the description of the embodiment, or can be changed accordingly and located in one or more devices different from this embodiment. The modules of the above embodiment can be combined into one module, or further split into multiple sub-modules.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for directional control and separation of charged particles in an electrolyte, characterized in that: include: A microfluidic channel, wherein the microfluidic channel has a plurality of ports including one or more injection ports and one or more outlet ports, and a fluid is provided to flow from the injection port toward the outlet port at a speed v0, and a separation chamber is formed inside the microfluidic channel, and the fluid contains charged particles, and the charged particles are separated inside the separation chamber; Two or more groups of electrodes, the number of electrodes in each group of electrodes is the same or different, each electrode is in contact with the fluid and forms a pseudocapacitor and / or double-layer capacitor at the interface between the electrode and the fluid, and the electrodes are arranged in parallel inside the microfluidic channel and the arrangement direction has a certain angle with the flow direction of the fluid; a plurality of conductor leads; and Two or more driving power supplies, each driving power supply is connected to one of the groups of electrodes, the driving power supply generates a periodic voltage or current excitation, and the voltage excitation or current excitation output by the driving power supply in one output cycle is in a changing state; Each electrode continuously and alternately charges and discharges, forming a traveling wave electric field with periodic amplitude changes in the microfluidic channel. The electric field force on the charged particles in the traveling wave electric field is decomposed into a first component and a second component that are perpendicular to each other. The first component is parallel to the direction of fluid movement and drives the charged particles to move along the direction of the first component. The second component is perpendicular to the direction of fluid movement and separates the charged particles according to different charge-to-mass ratios. The expression of the traveling wave electric field E is: Where A is the maximum amplitude of the traveling wave electric field, T0 is the period of the traveling wave electric field, θ is the angle between the parallel electrodes and the fluid flow direction, c is the phase of the traveling wave electric field, the lower left corner of the first electrode on the left is taken as the origin, the fluid flow direction is taken as the x-axis, and the direction rotated 90 degrees counterclockwise from the x-axis is taken as the y-axis. x and y are the horizontal and vertical coordinates of the midpoint of the traveling wave electric field, respectively. S0 is the period of the electric field intensity relative to the coordinate (x, y). The traveling wave electric field E moves at a preset traveling wave speed.

2. The device for controlling the direction and separating charged particles in an electrolyte according to claim 1, characterized in that: Charged particles are solid, gas, liquid or bubbles including cells, bacteria, microorganisms, proteins, vesicles, and / or Charged particles have either a positive or negative charge.

3. According to the device for directional control and separation of charged particles in an electrolyte as claimed in claim 1, the period, frequency and output voltage and / or current waveform of the driving power supply are all adjustable, and The amplitude of the traveling wave electric field, the positive-negative amplitude ratio and the traveling wave moving speed are all adjustable.

4. The device for controlling the direction and separating charged particles in an electrolyte according to claim 1, In one or more cycles of the traveling wave electric field, the total input current and the total output current on each electrode are equal, that is, the net input current and the net output current on each electrode are both zero; or The total input charge and total output charge on each electrode are always smaller than the total charge capacity of the electrode.

5. The device for controlling the direction and separating charged particles in an electrolyte according to claim 1, Where d is the horizontal spacing between adjacent electrodes.

6. The device for directional control and separation of charged particles in an electrolyte according to claim 1, wherein θ is between 0° and 90°.

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