CN213544171U - Device for separating multiple particles by utilizing light-induced dielectrophoresis - Google Patents

Abstract

The utility model belongs to the micro-electro-mechanical systems field specifically discloses a utilize device of light-induced dielectrophoresis separation multiple particle, including treating the separating reagent entry, the carrier fluid entry, the light guide layer, the microfluid passageway, the export of a particle, two exports of particle and three exports of particle, wherein the light guide layer is located microfluid passageway's top and length, width rather than unanimous. By applying light to different positions of the photoconductive layer, the conductivity of the corresponding positions can be changed, so that a non-uniform electric field is generated, and three types of particles in the microfluidic channel are driven to move. The radius and the dielectric constant of three kinds of particles are different, lead to the dielectrophoresis power size difference that it received, based on this, can separate different particles, the utility model has the advantages of: the needed particle samples are few, and the separation efficiency is high; the particles do not need to be marked, and the damage to the particles is small; the separation of the three particles can be realized by applying illumination to different positions according to requirements without designing complex channels and electrodes.

Description

Device for separating multiple particles by utilizing light-induced dielectrophoresis

Technical Field

The utility model relates to a micro-fluidic field, in particular to microfluid separation field mainly is a device that utilizes light induction dielectrophoresis to separate multiple particle with novel structure.

Background

The micro-fluidic chip becomes a popular field of research by the characteristics of miniaturization, portability, high integration degree, low cost and the like, and the supported micro-fluidic technology becomes a brand-new technology applied to multiple fields of machinery, biomedicine, chemical engineering, aerospace and the like; the micro-fluidic chip can be applied to the control, separation and screening of biological cells and micro-nano particles, and particularly has important application in the research fields of tumor cell research, somatic cell research, genome drawing and the like; in the course of the diagnosis and treatment of diseases, it is of great importance to separate the target cells from their surrounding environment.

In the microfluidic technology, the separation of micro-nano particles and cells can be divided into two types: one is to separate by using a special micro-channel structure and micro-fluid dynamic characteristics, and the other is to separate micro-nano particles or cells with different physical characteristics in a micro-channel by using different physical fields; the latter control method for micro-nano particles mainly comprises fluid dynamic separation, ultrasonic separation, magnetic field aggregation, optical tweezer driving, dielectrophoresis control method and the like, wherein the dielectrophoresis control method is used as a non-contact control mode, not only can realize various complex controls such as separation, transportation, capture, classification and the like of biological particles, but also is easy to integrate compared with other micro-control technologies, and can realize single or large-area control. However, the design of the electrode structure is closely related to the implemented manipulation function, and a series of special electrode structures are required to be designed and matched to accomplish the complex manipulation of the particles. The physical electrode used by the traditional dielectrophoresis has the problems of long design and processing period, high manufacturing cost, incapability of being changed after forming and the like, and greatly limits the application of the dielectrophoresis in biological manipulation.

Optoelectronic Tweezers (OET), also known as Optically induced dielectrophoresis (ODEP), is proposed by the Pei Yu child group and is a novel manipulation technique that combines optical electrodes with dielectrophoresis methods. The photoelectron tweezers is a tool which utilizes optical manipulation, realizes the manipulation of micro-nano-scale objects by projecting optical patterns on a photoconductive layer, and has the flexibility and the real-time property which are not possessed by the traditional dielectrophoresis manipulation while realizing the non-contact and non-damage manipulation of substances on the basis of the principle of light-induced dielectrophoresis manipulation, thereby greatly increasing the manipulability of particles. By using the application of the optical electrode in the field of xerography for reference, the optical electrode is used for replacing the traditional physical electrode for the first time, the period is extremely short from the determination of the operation function to the design and use of the electrode, the complex electrode manufacturing process is avoided, the particle operation flexibility is improved, and the processing cost is reduced. Because the dynamic optical virtual electrode can be generated, the particles can be more complicated to operate, the operation thought of the traditional dielectrophoresis is widened, and the dynamic optical virtual electrode has wide research value and application prospect.

Disclosure of Invention

An object of the utility model is to provide an utilize device of light-induced dielectrophoresis separation multiple particle compares with the traditional device that adopts the separation of dielectrophoresis technique, and the advantage lies in not designing complicated electrode structure, has further reduced the efficiency when having improved the separation particle in the time of the damage to the particle.

The technical scheme of the utility model is that: a device for separating a plurality of particles by utilizing light-induced dielectrophoresis comprises a reagent inlet to be separated, a carrier fluid inlet, a microfluidic channel, a photoconductive layer, a first particle outlet, a second particle outlet and a third particle outlet; injecting a reagent to be separated from an inlet of the reagent to be separated, injecting a carrier fluid (potassium chloride solution) from an inlet of the carrier fluid, and enabling the reagent to be separated and the carrier fluid to flow into the microfluidic channel after meeting; the separated first particle flows out from the first particle outlet, the second particle flows out from the second particle outlet, and the third particle flows out from the third particle outlet.

The utility model discloses a income lies in: compared with other micro-separation devices, the light-induced dielectrophoresis chip can avoid the damage of the electrode with complex shape to the particles; in addition, in order to ensure that three fragile particles are damaged less in the flowing process, a longer part is reserved at the joint of the reagent inlet to be separated, the carrier fluid inlet and the microfluidic channel to be used as a buffer structure, so that the three particles are well ensured not to be damaged greatly due to rapid structural change when passing through, and the structural integrity of the separated particles can be ensured; similarly, a section of buffering structure is arranged at the connection part of the first particle outlet, the second particle outlet and the microfluidic channel; considering the manufacturability of chip processing, the separating device has simple design, the structures of the two inlets and the three outlets are the same, the light guide layer is positioned above the microfluidic channel, and the three particles can be ensured to be subjected to light-induced dielectrophoresis force at each stage when flowing through the microfluidic channel through certain illumination, thereby ensuring the separating quality and efficiency.

Drawings

FIG. 1 is a schematic two-dimensional structure of an apparatus for separating a plurality of particles using light-induced dielectrophoresis, in which: 1. a reagent inlet to be separated 2, a carrier fluid inlet 3, a photoconductive layer 4, a microfluidic channel 5, a particle three outlet 6, a particle two outlet 7 and a particle one outlet.

FIG. 2 is a two-dimensional potentiometric map of an apparatus for separating a plurality of particles using light-induced dielectrophoresis, wherein a photoconductive layer is divided into two portions, a first portion being illuminated areas, five illuminated areas being staggered, and a second portion being non-illuminated areas positioned between each two illuminated areas, the illuminated areas of the photoconductive layer being illuminated by light to cause a change in conductivity in the photoconductive layer, thereby producing a non-uniform electric field within a space within a microfluidic channel.

FIG. 3 is a two-dimensional graph showing the separation effect of an apparatus for separating a plurality of particles by light-induced dielectrophoresis, wherein a first particle flows out from an upper first particle outlet, a second particle flows out from a middle second particle outlet, and a third particle flows out from a lower third particle outlet, and the separation effect is expected.

Detailed Description

The present invention will be further described with reference to the accompanying drawings, but the embodiments of the present invention are not limited thereto.

As shown in the attached figure 1, the device for separating a plurality of particles by utilizing light-induced dielectrophoresis comprises an inlet (1) of a reagent to be separated, an inlet (2) of a carrier fluid, a light-guiding layer (3), a microfluidic channel (4), a three-particle outlet (5), a two-particle outlet (6) and a one-particle outlet (7).

Specifically, the to-be-separated reagent inlet (1), the carrier fluid inlet (2) and the microfluidic channel (4) can be synchronously designed and simultaneously manufactured by a Micro Electro-Mechanical System (MEMS) micromachining process, which is an industrial technology integrating a microelectronic technology and a Mechanical engineering, and the operating range is in a micrometer range.

Specifically, the to-be-separated reagent inlet (1), the carrier fluid inlet (2), the microfluidic channel (4) and other channels can be manufactured by standard technologies such as a template hot pressing method or a template pouring method, in order to generate an alternating current electric field in the microfluidic channel (4), the top wall and the bottom wall of the microfluidic channel (4) are required to be made of transparent indium tin oxide glass, and the indium tin oxide glass has good light transmittance and electrical conductivity, so that electrical signals can be loaded on the surfaces of the top wall and the bottom wall of the microfluidic channel (4), namely, reactive ion etching is performed on the edges of the two indium tin oxide glasses on the same side to connect copper wires, so that the copper wires can be connected to a signal generator to provide voltage signals with certain amplitude and frequency.

Specifically, the reagent to be separated is injected from the inlet of the reagent to be separated, and the initial flow rate is 0.2 mm/s; the specific preparation method comprises the steps of taking a proper amount of purified water, adding a proper amount of potassium chloride into the purified water, and detecting the conductivity of the solution by using a conductivity meter to meet the requirement; the carrier fluid was injected from the carrier fluid inlet at an initial flow rate of 1.5 mm/s.

Specifically, the nonuniform electric field in the microfluidic channel is generated by illuminating the photoconductive layer, specifically, a function signal generator is connected to the upper end of the photoconductive layer and the lower end of the microfluidic channel, and the voltage is 5V alternating current; the light guide layer is divided into two parts, the first part is an illumination area which is respectively positioned at the left side, the right side and the middle part, the length of each section is 30 mu m, the second part is a non-illumination area which is positioned between every two illumination areas, and the length of each section is 60 mu m; the spatial potential profile is shown in figure 2.

Specifically, in order to form a microelectrode, a heavily doped hydrogenated amorphous silicon layer with the thickness of 50 nanometers, an intrinsic hydrogenated amorphous silicon layer with the thickness of 2 micrometers and a silicon carbide insulating film layer with the thickness of 25 nanometers are continuously deposited on the inner side surface of the indium tin oxide glass substrate at the top and/or the bottom wall of the microfluidic channel (4) by a plasma enhanced chemical vapor deposition method, and the multilayer film structure is the light guide layer (3).

Specifically, because the intrinsic hydrogenated amorphous silicon has good photosensitive characteristics, under non-illumination conditions, the hydrogenated amorphous silicon serves as an insulator to occupy more potential difference, so that an electric field in the microfluidic channel (4) is quite weak, but under illumination conditions (as shown in fig. 2), electron hole pairs (photogenerated carriers) increase the local conductivity of the illuminated area of the hydrogenated amorphous silicon, so that the hydrogenated amorphous silicon becomes a good conductor. Therefore, different partial pressures are generated in the illumination area and the dark area, a non-uniform electric field is generated in the microfluidic channel (4), light spots (optical patterns) at the illumination position are optical virtual electrodes, the non-uniform electric field can be generated in the microfluidic channel (4) under the illumination condition, and the three particles are separated under the action of light-induced dielectrophoresis force. Meanwhile, the silicon carbide insulating film can weaken the hydrolysis phenomenon occurring in the microfluidic channel (4), and the heavily doped hydrogenated amorphous silicon can reduce the contact resistance between the indium tin oxide glass substrate and the intrinsic state hydrogenated amorphous silicon layer.

Specifically, the conductivity of the first particle is 0.25S/m, and the dielectric constant is 50; the conductivity of the second particles is 0.31S/m, and the dielectric constant is 59; the conductivity of the third particle is 0.11S/m, and the dielectric constant is 70; if the three particles are uniformly regarded as micro-nano particles, the density of the micro-nano particles in the reagent to be separated is 1050kg/m³(ii) a The dynamic viscosity of the reagent to be separated was 0.001 pas.

Specifically, as shown in the separation effect diagram of fig. 3, the reagent to be separated flows in from the upper reagent inlet (1) to be separated, the potassium chloride solution flows in from the lower carrier fluid inlet (2), and joins in the microfluidic channel (4), and under the action of photo-induced dielectrophoresis, the three particles start to be separated. The first particle flows out from the upper particle outlet, the second particle flows out from the middle particle outlet, and the third particle flows out from the lower particle outlet, so that the separation effect is obvious and is in line with the expectation.

Specifically, the length of the microfluidic channel and the length of the light guide layer are not limited thereto, and the length thereof may be appropriately shortened or lengthened according to actual needs, and the illumination pattern may be changed to meet the actual separation needs as a standard.

Above-mentioned can not be right the utility model discloses carry out comprehensive injecing, other any changes or equivalent replacement mode that do not deviate from the utility model discloses technical scheme is all within the protection scope of the utility model.

Claims (5)

1. An apparatus for separating a plurality of particles using light-induced dielectrophoresis, comprising: comprises a reagent inlet (1) to be separated, a carrier fluid inlet (2), a photoconductive layer (3), a microfluidic channel (4), a three-particle outlet (5), a two-particle outlet (6) and a one-particle outlet (7); the structure length of the micro-fluid channel (4) is 580 μm, the width is 50 μm, and the height is 50 μm; the total length of the device is 850 mu m; the light guide layer (3) is positioned above the microfluidic channel (4), and has the same length and width as the microfluidic channel and the height of 2 mu m.

2. An apparatus for separating particles using light-induced dielectrophoresis according to claim 1, wherein: the reagent to be separated is injected from the reagent inlet (1) to be separated, and the potassium chloride solution is used as a carrier fluid and is injected from the carrier fluid inlet (2); and (3) the reagent to be separated and the potassium chloride solution flow into the microfluidic channel (4) after meeting, under the action of light-induced dielectrophoresis force, the first particles flow out from the first particle outlet (7), the second particles flow out from the second particle outlet (6), and the third particles flow out from the third particle outlet (5).

3. An apparatus for separating particles using light-induced dielectrophoresis according to claim 1, wherein: the surface of one side of the indium tin oxide glass is coated with the light guide layer (3) by spraying by adopting a plasma enhanced chemical vapor deposition method, the light guide layer (3) is of a multilayer film structure, and the materials of the light guide layer are silicon carbide, intrinsic hydrogenated amorphous silicon and heavily doped hydrogenated amorphous silicon from inside to outside in sequence.

4. An apparatus for separating particles using light-induced dielectrophoresis according to claim 1, wherein: the light is focused and reflected to the light guide layer (3) through an optical lens group and a plane mirror by adopting a light source of a common projector, an optical pattern is generated by projection on the surface of the light guide layer (3) under the illumination condition of the projector, and the shape of the generated pattern can be designed according to the requirement through programming software.

5. An apparatus for separating particles using light-induced dielectrophoresis according to claim 1, wherein: the included angles of the axis of the to-be-separated reagent inlet (1), the axis of the carrier fluid inlet (2), the axis of the particle first outlet (7), the axis of the particle third outlet (5) and the axis of the microfluidic channel (4) are 45 degrees, and the to-be-separated reagent inlet (1), the carrier fluid inlet (2), the particle first outlet (7) and the particle third outlet (5) are geometrically symmetrical with respect to the axis of the microfluidic channel (4) respectively; the included angle between the axis of the second particle outlet (6) and the axis of the micro-fluid channel (4) is 20 degrees.

Images