Apparatus for performing direction control and separation on charged particles in electrolyte

Abstract

An apparatus for performing direction control and separation on particles in an electrolyte. The apparatus comprises: a microfluidic channel (1), wherein the microfluidic channel (1) has a sample inlet (11) and a sample outlet (12), such that a fluid flows at a velocity V0 through the sample inlet (11) toward the sample outlet (12), a separation chamber is formed inside the microfluidic channel (1), and the fluid contains charged particles, which are separated inside the separation chamber; two or more groups of electrodes (2), wherein the number of electrodes in each group of electrodes (2) is the same or different, each electrode (2) is in contact with the fluid and forms a pseudocapacitor and / or a double-layer capacitor on the interface where the electrode (2) is in contact with the fluid, the electrodes (2) are arranged in parallel inside the microfluidic channel (1), and there may be a certain angle between the arrangement direction of the electrodes (2) and the flowing direction of the fluid; a plurality of conductor leads (3); and two or more driving power sources (4), wherein each driving power source (4) is connected to one group of electrodes (2), the driving power sources (4) generate periodic voltages or current excitations, and voltage excitations or current excitations output by the driving power sources (4) within one output period are in a changing state.

Description

A device for directional control and separation of charged particles in electrolyte TECHNICAL FIELD

[0001] The present application relates to the field of charged particle motion control, and in particular, to a device for directional control and separation of charged particles in electrolyte. BACKGROUND

[0002] Charged particles in liquid or gel will move under the action of electric field. By introducing electric current in the liquid or gel electrolyte to form an electric field, the fluid or the charged particles in the fluid can be operated and controlled.

[0003] Currently, the main way to introduce electric current in the fluid is to use a conductor electrode represented by graphite electrode, alloy electrode or some solid metals such as gold, platinum, etc. The electrode is usually placed perpendicular to the direction of fluid motion, and different charged particles are separated by controlling the displacement difference of charged particles in the electric field direction. The area where the electrode is located and the separation chamber are connected through a membrane-like structure to increase the fluid motion resistance, so as to avoid the flow of fluid, especially the particles in the fluid, to the electrode chamber. In the microfluidic chip, the application of voltage loss in this membrane-like structure is large, and the voltage efficiency is low. At the same time, the working voltage is too large, which in turn causes Joule heat, affecting the uniformity of the electric field, the stability of the electrolyte solution and the motion of the charged particles therein. In addition, in the working process of the conductor electrode, the carriers in the electrolyte solution are ions, and the carriers in the conductor are electrons, so there is an inevitable electrochemical reaction at the electrode-fluid interface 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 the local bubbles are an important reason for the failure of many microfluidic chips.

[0004] Figure 1 is a schematic diagram of a traditional free-flow electrophoresis device, 301 is a charged particle in a microfluid, which can 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 used to isolate the solution of the separation chamber 305 and the electrode chamber 306 to ensure a stable electric field in the separation chamber 305. 304 is the outer wall of the microfluidic channel, the fluid moves at a speed of v, the electric field is perpendicular to the direction of fluid motion, and when the fluid flows through the separation chamber 305, the charged particles in the fluid will have different speeds in the electric field due to their different charge quantities, masses and other properties, resulting in different displacement differences and separating different types of charged particles. Electrolysis reaction occurs at the electrode interface when the common electrode is connected to the electric signal, generating bubbles, and the electrophoresis system has low stability, and due to the existence of the membrane-like structure, the electric field strength applied in the separation chamber 305 is small, i.e. the voltage efficiency is low.

[0005] In US6890409, the method of separating the electrode part and the microfluidic channel is adopted to avoid the bubbles entering the microfluid. This scheme uses an additional channel to separate the bubbles generated by the electrode from the microfluid channel, which cannot be used in a closed fluid channel.

[0006] Chinese patent CN200455328C discloses a method of using the pulse electric field provided by the waveform generator to perform electroporation on the cell wall, using the electric field between multiple parallel electrodes to perform electroporation on the cell wall. By reciprocating current excitation between the electrodes, an alternating electric field is generated to weaken the electrochemical reaction at the electrode-fluid interface. This scheme cannot avoid the carrier exchange process between the electrode and the electrolyte, i.e., the electrolysis reaction, and the specific application range and the effect of the scheme are greatly limited.

[0007] Chinese patent CN108885189A discloses a device for separating and analyzing samples by microfluidic electrophoresis. The patent places electrodes in the electrolyte channels on both sides, and sets up an array of conductive channels between the electrolyte channels and the separation channel. These channels provide uniform electric field distribution while generating high fluid dynamics resistance. The products of the electrolysis reaction flow out through the electrolyte channels where the electrodes are located. The distance between the electrodes and the separation channel in this scheme is too large, the actual voltage 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 using a traveling wave electric field. This scheme uses a linear array of parallel electrodes, and applies electric signals with a certain phase difference to the electrodes to generate a traveling wave signal above the electrodes. By controlling the direction of the traveling wave signal, two kinds of charged particles are made to move forward and backward, respectively, to separate the two kinds of charged particles. This scheme has extremely low separation efficiency, and the bubble problem caused by the electrolysis reaction at the electrode-electrolyte interface cannot be solved, making it difficult to be practically applied.

[0009] In summary, the main shortcomings of the existing schemes are as follows:

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

[0011] 2. The commonly used electrode placement method is to fix the electrode device, with the electric field perpendicular to the direction of fluid motion. The distance between the electrodes is large, and the membrane-like structure between the electrodes and the separation chamber causes certain voltage loss. The actual voltage used for separation is low, resulting in extremely low voltage efficiency of the electric field, low separation efficiency, and serious limitation of application scenarios.

[0012] 3. Free flow zone electrophoresis, two electrodes provide a fixed electric field, high voltage will cause problems such as Joule heating, low separation efficiency, and cannot be applied on a large scale. SUMMARY

[0013] The present application provides a device for directional control and separation of charged particles in an electrolyte to solve the technical problems existing in the prior art.

[0014] To achieve the above purpose, the present application provides a device for directional control and separation of charged particles in an electrolyte, which comprises:

[0015] A microfluidic channel having a plurality of ports including one or more sample inlet ports and one or more sample outlet ports for fluid to flow from the sample inlet port to the sample outlet port at a speed v0, a separation chamber formed inside the microfluidic channel, and charged particles contained in the fluid, the charged particles being separated inside the separation chamber;

[0016] Two or more groups of electrodes, each group of electrodes having the same or different number of electrodes, each electrode being in contact with the fluid and forming a pseudo-capacitance and / or a double-layer capacitance on the interface between the electrode and the fluid, the electrodes being arranged in parallel inside the microfluidic channel and having a certain angle between the arrangement direction and the flow direction of the fluid;

[0017] A plurality of conductor leads; and

[0018] Two or more driving power sources, each driving power source being connected to one group of electrodes, the driving power source generating a periodic voltage or current excitation, the voltage excitation or current excitation output by the driving power source in an output period being in a changing state;

[0019] Each electrode is continuously charged and discharged to form a traveling wave electric field with a periodically changing amplitude in the microfluidic channel, the electric field force experienced by the charged particles in the traveling wave electric field being decomposed into a first component and a second component perpendicular to each other, the first component being parallel to the fluid motion direction and driving the charged particles to move along the first component direction, and the second component being perpendicular to the fluid motion direction and separating the charged particles according to different charge-to-mass ratios, the expression of the traveling wave electric field E being:

[0020] 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 included angle between the parallel electrodes and the fluid flow direction, c is the phase of the traveling wave electric field, the left lower corner of the first electrode on the left side is taken as the origin, the fluid flow direction is taken as the x-axis, and the direction of the x-axis counterclockwise rotated by 90 degrees is taken as the y-axis, x and y are the horizontal coordinate and vertical coordinate of the midpoint of the traveling wave electric field, respectively, and S0 is the period of the electric field intensity relative to the coordinates (x, y),

[0021] The traveling wave electric field E moves at a preset traveling wave speed.

[0022] In an embodiment of the present application, the charged particles are solids, gases, liquids or bubbles including cells, bacteria, microorganisms, proteins, vesicles, and / or

[0023] The charged particles carry positive or negative charges.

[0024] In an embodiment of the present application, the period, frequency, and the output voltage and / or current waveform of the driving power source are adjustable, and

[0025] The amplitude, positive-to-negative amplitude ratio, and traveling wave moving speed of the traveling wave electric field are adjustable.

[0026] In an embodiment of the present application, the total input current and the total output current on each electrode are equal in one or more periods of the traveling wave electric field, i.e., the net input current and the net output current on each electrode are both zero; or

[0027] The total input charge and the total output charge on each electrode are always less than the total charge capacity of the electrode.

[0028] In an embodiment of the present application, where d is the horizontal spacing between adjacent electrodes.

[0029] In an embodiment of the present application, θ is between 0° and 90°.

[0030] The device for directional control and separation of charged particles in an electrolyte provided by the present application has the following beneficial technical effects:

[0031] 1. Compared with traditional electrodes

[0032] ① The electrolytic reaction of the electrode is solved, and bubble generation is eliminated,

[0033] ② The passivation problem of the electrode after long-term use is solved, and the service life of the electrode is extended,

[0034] ③ The problem of charge capacity limitation is solved,

[0035] ④ The electrode toxicity caused by particle adsorption in the fluid is solved, and the long cycle stability of the electrode is greatly extended.

[0036] 2. Compared with existing electrode schemes

[0037] ① High voltage efficiency,

[0038] ② Fast speed of controlling charged particles, high separation efficiency,

[0039] ③ Can drive nanometer charged particles, providing very high current driving force at the micron and nanometer scales,

[0040] IV. The movement of charged particles can be precisely controlled,

[0041] V. Long-term stable operation greatly broadens the application scenarios.

[0042] In summary, in the micro-channel fluid system, the device for directionally controlling and separating charged particles in electrolyte provided by the present application has incomparable advantages over the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0044] Fig. 1 is a schematic diagram of a conventional free-flow electrophoresis device;

[0045] Fig. 2a is a schematic diagram of a new traveling wave electrophoresis separation device;

[0046] Fig. 2b is a sectional view of A-AA in Fig. 2a;

[0047] Fig. 3a is a schematic diagram of a device for directionally controlling and separating charged particles in electrolyte according to an embodiment of the present application;

[0048] Fig. 3b is a schematic diagram of the output voltage of the driving power supply in Fig. 3a;

[0049] Fig. 4a is a schematic diagram of a device for directionally controlling and separating charged particles in electrolyte according to another embodiment of the present application;

[0050] Fig. 4b is a sectional view of A-AA in Fig. 4a;

[0051] Fig. 4c is a schematic diagram of the output voltage of the driving power supply in Fig. 4a;

[0052] Fig. 4d is a diagram of the running trajectory of charged particles in Fig. 4a. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0054] Figure 2a is a schematic diagram of a new traveling wave electrophoresis separation device, Figure 2b is a cross-sectional view of A-AA in Figure 2a, as shown in Figures 2a and 2b, 301 is a charged particle in a microfluid, which can 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 capacitance / pseudo-capacitance structure, which solves the problem of bubble generation, the electrode is in direct contact with the medium where the charged particles are located, the electric field generated by the electrode directly acts on the charged particles, the voltage efficiency is improved, and the separation efficiency of the charged particles is high. The electrode is placed obliquely, the electric field between the electrodes has a certain angle with the direction of fluid movement, the electric field force generated 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 promote the forward movement of the charged particles, and the electric field perpendicular to the fluid is used to accurately screen and distinguish charged particles with different charge-to-mass ratios.

[0055] In Figures 2a and 2b, a certain charged particle is distributed in the fluid. The charged particle can be a solid, liquid or gas bubble with a size of several nanometers to several tens of microns. The charge can be a positive charge or a negative charge. When these charged particles are subjected to the action of an electric field force, they will produce movement relative to the fluid in which they are located.

[0056] On the basis of Figures 2a and 2b above, the present application provides a device for direction control and separation of charged particles in an electrolyte, as shown in Figure 3a, which is a schematic diagram of a device for direction control and separation of charged particles in an electrolyte according to an embodiment of the present application, which comprises:

[0057] A microfluid channel 1, the microfluid channel has a sample inlet port 11 and a sample outlet port 12, the fluid flows from the sample inlet port 11 towards the sample outlet port 12 at a speed v0, a separation chamber is formed inside the microfluid channel 1, there is no physical isolation between the separation chamber and the electrode chamber in the present application, the space inside the microfluid channel 1 can be regarded as a separation chamber, the fluid contains charged particles, 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 have positive or negative charges;

[0058] Two or more groups of electrodes 2, the number of electrodes in each group is the same or different, in this embodiment, there are two groups of electrodes, the first group of electrodes is connected with V1 and the number is two, the second group of electrodes is connected with V2 and the number is one, each electrode is in contact with the fluid and forms a pseudo-capacitance and / or a double-layer capacitance on the interface between the electrode and the fluid, the electrodes are arranged in parallel inside the microfluidic channel and the arrangement direction can have a certain angle with the flow direction of the fluid, the invention avoids the electrochemical reaction of the electrode interface through the pseudo-capacitance and the double-layer capacitance, the double-layer capacitance is to store charges by the double-layer generated by the adsorption of charged ions on the electrode surface in the electrolyte, there is no redox process involved, which fundamentally eliminates the generation of bubbles. The pseudo-capacitance stores and releases electric energy through the continuous, reversible and phase-change-free Faraday reaction of the electrode material at a specific potential, the electrode interface will not produce bubbles, has greater charge capacity and long cycle stability. The double-layer capacitance and the pseudo-capacitance are combined, a certain double-layer capacitance interface is obtained by arranging a larger surface area in the pseudo-capacitance electrode and processing the electrode surface, which can further increase the capacitance and improve the efficiency of the electrode;

[0059] A plurality of conductor leads 3; and

[0060] Two or more driving power sources 4 (V1 / V2), each driving power source is connected with one group of electrodes, the driving power source generates a periodic voltage or current excitation, the voltage excitation or current excitation output by the driving power source in an output period is in a changing state, the period, frequency and output voltage and / or current waveform of the driving power source 4 are adjustable, and the amplitude, positive-to-negative amplitude ratio and moving speed of the traveling wave electric field are adjustable;

[0061] Each electrode is continuously charged and discharged, 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 motion direction and drives the charged particles to move along the first component direction, the second component is perpendicular to the fluid motion direction and separates the charged particles according to different charge-to-mass ratios, and the expression of the traveling wave electric field E is:

[0062] 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 included angle between the parallel electrodes and the fluid flow direction, c is the phase of the traveling wave electric field, as shown in FIG. 3, 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 coordinate and vertical coordinate of the midpoint of the traveling wave electric field, respectively, and S0 is the period of the electric field intensity relative to the coordinates (x, y),

[0063] The traveling wave electric field E moves at a preset traveling wave speed.

[0064] As shown in Fig. 3a, the present application places electrodes inside the separation chamber, directly uses the traveling wave electric field to separate charged particles, reduces voltage loss, and improves the voltage efficiency of the device. The electrodes are placed below and / or above the separation chamber, and there can 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, with no voltage loss and improved electrode efficiency. Charged particles in the fluid will produce a movement parallel to the direction of the electric field under the action of the electric field, which is superimposed with the fluid movement to form the movement of the charged particles. Due to the different charges and masses of different charged particles, there is a difference in the displacement of the position on the y-axis (the y-axis is defined as the direction perpendicular to the fluid movement), thereby achieving the separation of different particles in the medium.

[0065] The traveling wave electric field refers to the migration electric field formed by the periodic charging and discharging of multiple electrodes in time, which moves forward or backward according to the voltage change, i.e., the electric field between every two electrodes will move forward or backward over time. The traveling wave electric field has periodicity in time and space, i.e., the direction of the electric field at different times and positions is periodically alternating between positive and negative. When the charged particles are in the positive electric field, they will move to the right and upward, and when they are in the negative electric field, they will move to the right and downward. Overall, the trajectory of the charged particles is a certain wave fluctuation and moves upward. The mobility and speed of charged particles with different charge-to-mass ratios in the electric field will have certain differences in their trajectories in the electric field. By controlling the speed, frequency, phase, and other factors of the traveling wave electric field, the offset of a specific particle when it leaves the electric field is offset, and the charged particles entering the electric field at different times are at the same position when they leave the electric field, and the trajectory of the charged particles tends to be a straight line. Other charged particles fluctuate in a certain wave form when they leave the electric field, which separates and enriches the specific charged particles. That is, by adjusting the angle of the electrodes, the size and period of the electric field, and other factors, the target charged particles can be separated in the form of a straight line or an approximate straight line (concentrated in a specific area) at certain times.

[0066] During the operation of the electrodes, the traveling wave electric field is realized in time by the rotation of the charging and discharging of the electrodes, and the charged particles in the fluid are controlled. The electrodes work in anode mode and cathode mode at different times, ensuring that the charge output of each electrode does not exceed its charge capacity, and the transformation of charge carriers is completed inside the electrode, eliminating the generation of bubbles and Joule heat by electrolytic reaction. This greatly improves the voltage efficiency of the electrode, reduces the separation time, and improves the separation efficiency.

[0067] The traveling wave electric field E moves forward or backward in the microfluidic channel 1 in a sinusoidal form, and is periodically distributed in time t and x, y. The moving direction and speed of the traveling wave electric field E are fixed. Assuming that the traveling wave electric field E is not moving, the charged particles completely pass through the positive and negative electric fields in the process of movement. In the device shown in Fig. 3a, two groups of electrodes are arranged in the microfluidic channel 1, and the two groups of electrodes are arranged in parallel and staggered. They are respectively connected to the driving power supply V1 and the driving power supply V2. Fig. 3b is a schematic diagram of the output voltage of the driving power supply in Fig. 3a. When V1 and V2 are not equal, there will be alternating electric fields with equal size and opposite direction between the two groups of electrodes, which are Ep=(V2-V1) / (d*sin(θ)) and En=(V1-V2) / (d*sin(θ)) respectively. By periodically charging and discharging the electrodes, an asymmetric traveling wave electric field is formed in space, which solves the problem of capacitive charge limitation, improves the voltage threshold, and improves the separation efficiency.

[0068] The charged particles q in the microfluidic channel 1 are subjected to electrostatic force in Ep / En, and a migration speed v is generated, which is proportional to the electric field intensity and the charge-to-mass ratio of the charged particles q+ / v q- . There is a deflection angle θ between the parallel electrodes and the fluid velocity. The electrostatic force can be decomposed into v x+ parallel to the fluid velocity v0, i.e. in the x direction, and v y+ perpendicular to the fluid velocity v0, i.e. in the y direction. In the negative electric field, the corresponding values are v x- and v y- .

[0069] Assuming that the fluid moves at a constant speed and the flow rate v0 is constant. In the Ep action interval, the horizontal movement speed of the charged particles is v0-v x+ , the direction is to the right, and the vertical movement speed is v y+ , the direction is upward, so the combined movement direction of the charged particles is in the first quadrant, i.e. moving to the right and upward. Since the electrodes are arranged at an angle, the horizontal movement distance of the charged particles in the Ep interval is greater than d, and the time t1>d / (v0-v x+ ). In the En action interval, the horizontal movement speed of the charged particles is v0+v x- , the direction is to the right, and the vertical movement speed is v y- , the direction is downward, so the combined movement direction of the charged particles is in the fourth quadrant, i.e. moving to the right and downward. Since the electrodes are arranged at an angle, the horizontal movement distance of the charged particles in the Ep interval is less than d, and the time t2<d / (v0+v x- ), thus t1>d / (v0-v x+ )>d / (v0+v x- )>t2. v y+ and v y-Equal size and opposite direction, charged particles after a pair of positive and negative electric field action interval Ep and En, because of the different time of action, v y+ *t1>v y- *t2, that is, the vertical migration distance of the Ep interval is greater than the vertical migration distance of the En interval, the charged particles move vertically in the electric field. The movement speed is determined by the strength of the electric field Ep / En, the charge-to-mass ratio of the charged particles, the liquid viscosity coefficient, the electrode deflection angle θ, and the flow rate v0, the electrode distance d, and other parameters.

[0070] Different charge-to-mass ratio of charged particles after a pair of electric field region, produce controllable vertical motion. The amplitude is independent of the order of Ep / En action, so the order of V1 / V2 is periodically exchanged, and the electrode only needs to provide a reciprocating driving current to the fluid. Under the condition of constant electric field amplitude, the charge capacity load requirement of the electrode can be reduced by reducing the exchange period. The typical period is set to be no less than v0 / (2*d).

[0071] By adjusting the voltage amplitude of V1 / V2, the size of Ep / En and the specific electric field waveform can be controlled, and the charged particles with different charge-to-mass ratios in the medium can be accurately controlled.

[0072] Figure 4a is a schematic diagram of a device for controlling and separating charged particles in an electrolyte according to another embodiment of the present application. As shown in Figures 4a and 4b, 301 is the outer wall of the microfluidic channel, 302 and 303 are electrodes, 304 is a charged particle, 306 is a conductor lead, and V1-V4 are driving power sources. The fluid moves at a certain fixed speed v, and the electrodes 302 and 303 are alternately charged and discharged. The angle between the direction of the electric field E between the electrodes and the flow velocity v is greater than zero.

[0073] Figure 4a uses four electrodes as a group. By applying electric signals with a certain phase difference to the four electrodes respectively, a traveling wave electric field is generated in the fluid. Figure 4c is a schematic diagram of the output voltage of the driving power source in Figure 4a. The expression of the traveling wave electric field generated is which indicates that the electric field presents periodic distribution in time t and x, y directions. k=tanθ, θ is the angle between the parallel electrode 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°. By adjusting θ, the motion of the charged particles can be controlled. The motion of the charged particles in the traveling wave electric field will pass through many groups of alternating positive and negative electric fields, producing a vertical shift in the direction of the flow channel.

[0074] The setting mode of the x-axis and y-axis in Fig. 4a is the same as that in Fig. 3a, the movement speed of the charged particle in the x direction is x'(t)=-m*E(t,x,y)*sinθ+v0, and the movement speed of the charged particle in the y direction is y'(t)=m*E(t,x,y)*cosθ. The movement trajectory of the charged particle can be solved by substituting the above electric field E into the equation, and the displacement of the charged particle in the y direction will fluctuate and offset upward with the increase of time. Since the general solution of the differential equation is not easy to obtain, the numerical solution of the differential equation is obtained by using matlab.

[0075] Fig. 4d is a top view of the electric field, and the dashed line in the figure represents the movement trajectory of the charged particle. The charged particle will fluctuate and offset upward in the electric field with the increase of time, and the offset size is affected by the frequency and phase related parameters of the electric field. The charged particles entering the electric field at different time points are different by a time t0, and the movement trajectory equation of the charged particles is different by a phase. By adjusting the angle and speed of the traveling wave electric field and other factors, the y direction offset caused by the phase is offset at the end position of the electric field. The charged particle is at the same position when leaving the electric field, that is, in the form of a straight line, and is better enriched in specific charged particles. The longitudinal displacement deviation c of other charged particles is different, and the positions of the charged particles entering the electric field at different times will fluctuate when leaving the electric field, showing a fluctuating form. The speed and movement trajectory are different, so that different charged particles are distinguished from specific charged particles when leaving the electric field, and the separation of the charged particles in the medium is completed.

[0076] For charged particles with different charge-to-mass ratios, the movement speed and movement trajectory are different. By adjusting the position of the input of the charged particles and the phase of the traveling wave electric field, the movement of different charged particles and the timing of the disappearance of the displacement deviation of specific charged particles are controlled, so that the displacement of different charged particles in the y direction is different, so that the separation of the charged particles is completed.

[0077] In an embodiment of the present application, the total input current and the total output current of each electrode are equal in one or more periods of the traveling wave electric field, that is, the net input current and the net output current of each electrode are both zero; or

[0078] The total input charge and the total output charge of each electrode are always less than the charge capacity of the electrode.

[0079] In an embodiment of the present application, Wherein d is the horizontal spacing between adjacent electrodes.

[0080] In an embodiment of the present application, θ is between 0° and 90°.

[0081] The device for direction control and separation of charged particles in an electrolyte provided by the present application has the following beneficial technical effects:

[0082] 1. Compared with traditional electrodes

[0083] ①Solve the electrolysis reaction of the electrode, eliminate the generation of bubbles,

[0084] ②Solve the passivation problem of the electrode after long-term use, prolong the service life of the electrode,

[0085] ③Solve the problem of charge capacity limitation,

[0086] ④Solve the electrode toxicity caused by the adsorption of particles in the fluid, greatly extend the long cycle stability of the electrode.

[0087] 2. Compared with the existing electrode scheme

[0088] ①High voltage efficiency,

[0089] ②Fast speed of manipulating charged particles, high separation efficiency,

[0090] ③Can drive nanometer particles to carry electrons, providing high current driving force at micron and nanometer scales,

[0091] ④Can accurately control the movement of charged particles,

[0092] ⑤Long-term stable operation, greatly expanding the application scenarios.

[0093] In summary, in the micro-channel fluid system, the device for controlling and separating charged particles in the electrolyte provided by the present application has incomparable advantages compared with the existing scheme.

[0094] Those skilled in the art can understand that the drawings are only schematic diagrams of an embodiment, and the modules or processes in the drawings are not necessarily necessary for implementing the present application.

[0095] Those skilled 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 and located in one or more devices different from the present embodiment. The modules of the above-mentioned embodiments can be combined into one module, or can be further split into multiple sub-modules.

[0096] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An apparatus for directional control and separation of charged particles in an electrolyte, characterized by, The device comprises: a microfluidic channel having a plurality of ports including one or more sample inlet ports and one or more sample outlet ports, through which a fluid flows at a velocity v0from the sample inlet ports to the sample outlet ports, and a separation chamber formed inside the microfluidic channel, the fluid containing charged particles, the charged particles being separated inside the separation chamber; two or more groups of electrodes, each group having the same or different number of electrodes, each electrode being in contact with the fluid and forming a pseudo-capacitance and / or a double-layer capacitance on the interface between the electrode and the fluid, the electrodes being arranged in parallel inside the microfluidic channel and at an angle with respect to the flow direction of the fluid; a plurality of conductor leads; and two or more driving power sources, each driving power source being connected to one group of electrodes, the driving power sources generating periodic voltage or current excitation, the voltage or current excitation output by the driving power sources in one output cycle being in a changing state. Each electrode is continuously charged and discharged, forming a traveling wave electric field with a periodically changing amplitude in the microfluidic channel, and the electric field force on 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 motion direction and drives the charged particles to move along the first component direction, and the second component is perpendicular to the fluid motion direction and separates the charged particles according to different charge-to-mass ratios, and the expression of the traveling wave electric field E is: wherein A is the maximum amplitude of the traveling wave electric field, T0is the period of the traveling wave electric field, θ is the included angle between the parallel electrodes and the flow direction of the fluid, c is the phase of the traveling wave electric field, the left lower corner of the first electrode on the left is taken as the origin, the flow direction of the fluid 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 coordinate and vertical coordinate of the midpoint of the traveling wave electric field, respectively, and S0is the period of the electric field intensity with respect to the coordinates (x, y), the traveling wave electric field E moves at a preset traveling wave speed.

2. The device for directional control and separation of charged particles in an electrolyte according to claim 1, characterized in that, the charged particles are solid, gas, liquid or bubbles including cells, bacteria, microorganisms, proteins and vesicles, and / or the charged particles have positive or negative charges.

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

4. The device for directional control and separation of charged particles in an electrolyte according to claim 1, in one or more periods of the traveling wave electric field, the total input current and the total output current on each electrode are equal, i.e., the net input current and the net output current on each electrode are zero; or the total input charge and the total output charge on each electrode are always less than the total charge capacity of the electrode.

5. The apparatus for directional control and separation of charged particles in an electrolyte of 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°.

Images