CN110385150A - Dielectric particles manipulate chip - Google Patents

Abstract

A kind of dielectric particles manipulate chip, comprising chip body, be arranged at intervals on the chip body top surface first electrode layer and the second electrode lay and an overlay masking described in electrode layer dielectric layer.The first electrode layer has multiple first fourchette electrode portions, and the second electrode lay has multiple second fourchette electrode portions, and the first fourchette electrode portion and the second fourchette electrode portion are staggered distribution at each interval.The dielectric layer is made of high-dielectric coefficient semiconductor inorganic materials, and dielectric coefficient is between 3.7~80F/m.Pass through the design using high-dielectric coefficient semiconductor inorganic materials as the dielectric layer, the thickness of the dielectric layer can substantially be reduced, and dielectric particles can be greatly improved with the driving voltage of more low potential and frequency and be steered movement speed, it is a kind of dynamical innovation dielectric particles manipulation chip design.

Description

Dielectric Particle Control Chip

technical field

The invention relates to a microfluidic chip, in particular to a microfluidic chip for manipulating the movement of dielectric particles.

Background technique

In the field of microfluidic chips, there are two main methods to control the movement of dielectric particles, one is to use dielectrophoresis force (DEP force), and the other is to use AC electroosmosis force (ACEO force) The resulting liquid eddy current, for example, was previously applied for by the applicant of this case in the Taiwan region of China patent I507803 "Dielectric Particle Manipulation Chip and Its Manufacturing Method and Method for Manipulating Dielectric Particles". This patent case mainly utilizes the structural design of two interdigitated electrode layers arranged on the top surface of the chip body, and the structural design of the dielectric layer covering the electrode layer, so that dielectrophoretic force and alternating current percolation can be used simultaneously. The interaction of the force is used to manipulate the displacement of the dielectric particles in the sample fluid, which can be used to concentrate a small amount of specific dielectric particles dispersed in the sample fluid on a specific part of the chip for subsequent inspection.

Although this patent has been able to successfully integrate and utilize the above two forces to manipulate dielectric particles, the dielectric layer covering the electrode layer is made of photoresist material, such as SU-8 photoresist Due to the material characteristics of the photoresist itself, the thickness of the dielectric layer formed by its coating will be as high as 1200nm, so the distance between the electrode layer and the dielectric particles in the sample liquid above the dielectric layer It is so far away that the driving voltage for driving the electrode layer to generate the dielectrophoretic force and the alternating current percolation force needs to be above 40V _pp , and the frequency of the driving voltage needs to be as high as above 1000Hz.

Contents of the invention

The object of the present invention is to provide a dielectric particle control chip that can improve at least one shortcoming of the prior art.

The dielectric particle control chip of the present invention includes a chip body, a first electrode layer and a second electrode layer arranged at intervals on the top surface of the chip body, and an arrangement covering and shielding the first electrode layer and the second electrode layer The dielectric layer fixed on the top surface of the chip body. The first electrode layer has a first connection portion and a plurality of first interdigitated electrode portions, the second electrode layer has a second connection portion spaced apart from the first connection portion and a plurality of second interdigitated electrode portions, The first interdigitated electrode portion extends from the first connection portion toward the second connection portion, the second interdigitated electrode portion extends from the second connection portion toward the first connection portion, the The first interdigitated electrode parts and the second interdigitated electrode parts are alternately arranged and distributed at intervals. The dielectric layer is made of high-permittivity semiconductor inorganic material, and the dielectric coefficient of the high-permittivity semiconductor inorganic material is between 3.7-80F/m.

In the dielectric particle control chip according to the present invention, the first electrode layer and the second electrode layer are arranged on the chip body radially inwardly and outwardly, and the second connecting part is annular and spaced around On the radially outer side of the first connecting portion, the second interdigitated electrode portions protrude radially inward from the second connecting portion toward the first connecting portion at intervals along the inner periphery of the second connecting portion The first interdigitated electrode portions extend radially outward toward the second connection portion at intervals along the periphery of the first connection portion.

In the dielectric particle control chip of the present invention, the high dielectric constant semiconductor inorganic material is selected from SiO ₂ , Si ₃ N ₄ , HfO ₂ and TiO ₂ .

In the dielectric particle control chip of the present invention, the thickness of the dielectric layer is in the range of 100-300nm.

In the dielectric particle control chip of the present invention, the high dielectric constant semiconductor inorganic material is coated and fixed on the chip body by electroplating, physical vapor deposition, chemical vapor deposition or spin coating.

In the dielectric particle control chip according to the present invention, each first interdigitated electrode part is in the shape of a strip extending radially outward from the first connecting part and has the same width, and each second interdigitated electrode part is elongated from the first connecting part. The second connecting portion extends radially inwards to form a triangle whose width gradually narrows.

The beneficial effect of the present invention is that: the present invention can greatly reduce the thickness of the dielectric layer through the design of the high-permittivity semiconductor inorganic material as the dielectric layer, so that the manufactured dielectric particles can control the chip with a lower potential and The high-frequency driving voltage drives the dielectric particles in the dielectrophoretic fluid, and can greatly increase the moving speed of the manipulated dielectric particles. It is a more energy-saving, environmentally friendly and high-performance innovative dielectric particle control chip.

Description of drawings

Other features and effects of the present invention will be clearly presented in the implementation manner with reference to the drawings, wherein:

FIG. 1 is a perspective view of a first embodiment of a dielectric particle control chip of the present invention;

Fig. 2 is a schematic top view of the first embodiment;

Fig. 3 is a sectional view along line 3-3 of Fig. 2;

FIG. 4 is a signal curve diagram of the moving speed of the dielectric particles corresponding to the applied AC voltage in the first embodiment, wherein the dielectric layer of the dielectric particles controlling the chip is SiO ₂ ;

FIG. 5 is a signal curve diagram of the flow rate of dielectric particles corresponding to the applied AC voltage in the first embodiment, wherein the dielectric layer of the dielectric particle control chip is Si ₃ N ₄ ;

FIG. 6 is a signal curve diagram of the flow rate of the dielectric particles corresponding to the applied AC voltage in the first embodiment, wherein the dielectric layer of the dielectric particle control chip is HfO ₂ ;

FIG. 7 is a signal curve diagram of the flow rate of dielectric particles corresponding to the applied AC voltage in the first embodiment, wherein the dielectric layer of the dielectric particle control chip is TiO ₂ ;

FIG. 8 is a signal curve diagram of the flow velocity of the dielectric particles corresponding to the applied AC voltage in the first embodiment, illustrating that when _SiO2 is used as the dielectric layer, the flow velocity of the dielectric particles is controlled under different dielectric layer thickness conditions;

Fig. 9 is a schematic top view of another implementation of the first embodiment; and

FIG. 10 is a schematic top view of a second embodiment of the dielectric particle control chip of the present invention, illustrating the distribution state of the first electrode layer and the second electrode layer.

Detailed ways

The present invention will be further described with respect to the following examples, but it should be understood that the examples are for illustrative purposes only, and should not be construed as limitations on the implementation of the present invention, and similar components are based on the same represented by the number.

Referring to Figures 1, 2, and 3, the first embodiment of the dielectric particle control chip 3 of the present invention is suitable for manipulating a plurality of dielectric particles in the dielectrophoretic fluid through the interaction of the dielectrophoretic force and the alternating current osmotic force. Transfer, blend and collect concentrates. The dielectric particles may be latex particles, or biological particles such as cells, bacteria, and yeasts, but the dielectric particles are not limited to the above types during implementation.

The dielectric particle control chip 3 includes a chip body 4, a first electrode layer 5 and a second electrode layer 6 coated on the top surface of the chip body 4 at intervals, and a layer covering the chip body 4 and covering and shielding the chip body. The dielectric layer 7 of the first electrode layer 5 and the second electrode layer 6 .

It must be noted that, since the structures of the first electrode layer 5, the second electrode layer 6 and the dielectric layer 7 are all in the micron or nanometer scale, for the convenience of understanding, each component in the drawing is only an enlargement of the original structure Schematic diagram. During implementation, the dimensions and specifications of the components are not limited to the proportions shown in the drawings.

The first electrode layer 5 has a circular first connecting portion 51 , and a plurality of first interdigitated electrode portions 52 radially distributed along the periphery of the first connecting portion 51 and extending radially outward from the first connecting portion 51 . , and a first conductive portion 53 extending radially outward from the first connecting portion 51 and used for conducting alternating current. The second electrode layer 6 has a substantially ring-shaped second connecting portion 61 disposed around the first connecting portion 51 at intervals, and a plurality of radially inwardly distributed along the inner periphery of the second connecting portion 61 . A second interdigitated electrode portion 62 extending from the first connecting portion 51 , and a second conductive portion 63 extending radially outward from the second connecting portion 61 for conducting alternating current. Each first interdigitated electrode part 52 is in the shape of a long strip extending in equal width, and each second interdigitated electrode part 62 is in the form of a triangle whose width gradually narrows radially inward, and the first interdigitated electrode part 52 The second interdigitated electrode parts 62 are arranged in a staggered manner around the center of the first connecting part 51 .

In the first embodiment, the first electrode layer 5 and the second electrode layer 6 are made of ITO (indium tinoxide), and are disposed on the chip body 4 through micro-electro-mechanical process. However, during implementation, the materials of the electrode layers 5 and 6 are not limited thereto. In addition, in this first embodiment, the radius of the first connecting portion 51 is 400um, the width of each first interdigitated electrode portion 52 is 50um, and the extension length is 3150um, and the inner peripheral radius of the second connecting portion 61 is 3580um, the distance between each adjacent first interdigitated electrode part 52 and each second interdigitated electrode part 62 is 35um, and the distance between the end of each first interdigitated electrode part 52 and the inner periphery of the second connecting part 61 The pitch is 30um.

The dielectric layer 7 is made of a high-permittivity semiconductor inorganic material, and the dielectric coefficient of the high-permittivity semiconductor inorganic material ranges from 3.7 to 80 F/m. In the first embodiment, the dielectric layer 7 is formed on the chip body 4 by electroplating, and its thickness is between 100-300 nm. However, during implementation, there are many ways to coat the chip body 4 with a high-permittivity semiconductor inorganic material to form a thin-film dielectric layer 7, such as by chemical vapor deposition (CVD), physical vapor deposition (PVD), or Spin-coating methods such as spin-on-glass (SOG) and spin-on-dielectric (SOD).

When the dielectric particle control chip 3 is used, alternating currents of specific voltage, frequency and waveform can be applied to the first electrode layer 5 and the second electrode layer 6 respectively, and the two alternating currents have a phase difference of 180°. One interdigitated electrode part 52 and the second interdigitated electrode part 62 generate a negative dielectrophoretic force, and the specific dielectric particles in the dielectrophoretic liquid suspended above it are attracted downwards and close to the top surface of the dielectric layer 7, The space is located directly above each first interdigitated electrode portion 52 and each second interdigitated electrode portion 62, and then the AC electroosmotic force field formed between the first electrode layer 5 and the second electrode layer 6 is used to drive the The specific dielectric particles close to the dielectric layer 7 are attracted downward to move and concentrate toward the center of the first connecting portion 51 , so as to achieve the purpose of collecting the specific dielectric particles in the dielectrophoretic liquid.

Two experimental examples are used below to illustrate the effect of the dielectric particle control chip 3 of the present invention on controlling the dielectric particles. In the following experimental examples, there are four kinds of high-permittivity semiconductor inorganic materials used in the dielectric layer 7 of the dielectric particle control chip 3 of the present invention, namely SiO ₂ (Silicon dioxide), HfO ₂ (Hafnium dioxide) , TiO ₂ (Titaniumdioxide), and Si ₃ N ₄ (Silicon nitride), and the dielectric particle control chip composed of the existing dielectric layer material (SU-8 photoresist) disclosed in the prior art of this case was used as a control group . Among them, the dielectric coefficient of SiO ₂ is 3.7F/m, that of Si ₃ N ₄ is 7.5F/m, that of HfO ₂ is 25F/m, and that of TiO ₂ is 80F/m.

The dielectric particles used in the above experimental examples are lactic acid bacteria (LAB for short, BCRC910525), and the live lactic acid bacteria are diluted with secondary water (DI water) to prepare the dielectrophoretic solution containing bacteria for the experiment. The concentration of lactic acid bacteria in the electrophoresis solution is 1×10 ⁶ CFU/ml. Since it is a prior art to prepare the dielectrophoresis solution with bacteria, it will not be described in detail. During implementation, the microscope equipment (OLYMPUS IX70) equipped with an image capture device (microfire CCD camera) is used to capture the microscopic image of each dielectric particle control chip 3, and the imaging rate is 10 frames/sec, so as to analyze the dielectric particles movement speed.

The SU-8 photoresist is coated on the chip body by spin coating, and the thickness of the formed dielectric layer is 1200nm, and under the conditions of the driving voltage (10V _pp ~ 50 V _pp ) used in the experiment, The frequency of the driving voltage must reach 1000 Hz, so that the generated AC electroosmotic force field is sufficient to drive the movement of the dielectric particles in the dielectrophoretic fluid. In the experiment of the effect of the type of dielectric layer on the control of the flow rate by dielectric particles, the thickness of the dielectric layer 7 in this case was fixed at 200 nm, the driving voltage range was from 4V _pp to 12V _pp , and the driving voltage frequency range was from 100Hz to 500Hz. In the experiment of the influence of the thickness of the dielectric layer on the flow rate controlled by the dielectric particles, the thickness of the dielectric layer 7 in this case ranges from 100nm to 300nm, the driving voltage ranges from 4 V _pp to 12V _pp , and the driving voltage frequency is fixed at 500Hz .

Referring to Figures 2, 4-7, it can be seen from the signal curves of the control group that when the driving voltage frequency is _1000Hz , as the driving voltage potential increases, the moving speed of the dielectric particles also slowly increases. Under the condition of high driving voltage, the maximum flow velocity of dielectric particles is only 18μm/sec. On the contrary, when _SiO2 is used as the dielectric layer 7, when the driving voltage frequency is 100Hz, 300Hz and 500Hz, only the driving voltage of 4V _pp can drive the dielectric particles to move. When the driving voltage is increased to 12V _pp , the dielectric particles The moving speed of electric particles can reach 18μm/sec. When HfO ₂ is used as the dielectric layer 7, when the driving voltage frequency is 100 Hz and the driving voltage is 12 V _pp , the flow velocity of the dielectric particles can be as high as 80 μm/sec. Similarly, the dielectric particles control chip 3 made of the dielectric layer 7 of the other two dielectric materials can also drive the dielectric particles to generate a high flow rate under the above driving voltage conditions.

Referring to Figures 2 and 8, taking SiO ₂ as the dielectric layer 7 as an example, under the frequency condition of a fixed driving voltage, when the thickness of the dielectric layer 7 is 100nm and 300nm, a very low driving voltage is also required, and various The dielectric particle movement speed (greater than 40 μm/sec) produced by the thickness of the dielectric layer 7 under the condition of 12V _pp is significantly higher than that of the existing SU-8 photoresist made of dielectric particles to control the movement of dielectric particles in the chip Speed (about 20μm/sec).

Referring to Figures 2 and 9, in this first embodiment, the shape of the second connecting portion 61 of the second electrode layer 6 is designed to be circular, but in practice, in other embodiments of the present invention, the The shape of the second connecting portion 61 can be changed to other geometric ring shapes, such as the rectangular ring shape shown in FIG. 9 .

It must be noted that when there are dielectric particles with different dielectric properties in the dielectrophoretic fluid, the AC conditions applied to the first electrode layer 5 and the second electrode layer 6 can be adjusted, such as a specific voltage and a specific frequency Make the electrode layers 5, 6 cooperate to produce different dielectrophoretic force and alternating current percolation force for dielectric particles with different dielectric properties, and can be used to control the movement of dielectric particles with different dielectric properties for classification Collection, such as sorting and collecting dead bacteria and live bacteria, etc., but its implementation and application methods are not limited to this. Due to the application of specific alternating current conditions between the two electrode layers 5 and 6, different dielectrophoretic forces and alternating current percolation forces are generated for dielectric particles with different dielectric properties, and the movement of various dielectric particles in the dielectrophoretic fluid is controlled. It is prior art, so it will not be described in detail.

Referring to FIG. 10 , the difference between the second embodiment of the dielectric particle control chip 3 of the present invention and the first embodiment lies in the shape design of the first electrode layer 5 and the second electrode layer 6 . For convenience of description, only the differences between the second embodiment and the first embodiment will be described below.

In the above-mentioned first embodiment, the first electrode layer 5 and the second electrode layer 6 of the dielectric particle control chip 3 are designed to be radially spaced from inside to outside, but in this second embodiment, the first The connecting portion 51 and the second connecting portion 61 are designed to be long strips extending back and forth and parallel to the left and right intervals. The first interdigitated electrode portions 52 are distributed along the length of the first connecting portion 51 at intervals, and toward the second The two connecting parts 61 extend in the direction, and the second interdigitated electrode parts 62 are spaced along the length of the second connecting part 61 and extend toward the first connecting part 51. The first interdigitated electrode parts 52 and The second interdigitated electrode portions 62 are arranged in a staggered manner at intervals from each other.

With this structural design, it is also possible to use high-permittivity semiconductor inorganic materials as the design of the dielectric layer 7, greatly reduce the thickness of the dielectric layer 7, and reduce the need for driving the dielectric particles to control the chip 3. The electric potential and frequency of the alternating current of the dielectrophoretic force and the alternating current osmotic force can effectively increase the controlled moving speed of the dielectric particles.

In summary, the present invention can greatly reduce the thickness of the dielectric layer 7 by using high-permittivity semiconductor inorganic materials as the design of the dielectric layer 7, so that the dielectric particle control chip 3 can be controlled at a lower cost. The driving voltage of potential and frequency drives the dielectric particles in the dielectrophoretic fluid, and can greatly increase the moving speed of the manipulated dielectric particles, which can greatly shorten the collection and concentration time of specific dielectric particles in the sample fluid, thereby shortening the test time. It is a very innovative and high-efficiency dielectric particle control chip 3 design. Therefore, the object of the present invention can be achieved indeed.

However, the above descriptions are only embodiments of the present invention, and should not limit the scope of the present invention. All simple equivalent changes and modifications made according to the scope of the claims of the present invention and the contents of the description are still the same. It belongs to the scope covered by the patent of the present invention.

Claims (6)

1. a kind of dielectric particles manipulate chip, comprising chip body, it is arranged at intervals at the first electrode of the chip body top surface First electrode layer described in layer and the second electrode lay and overlay masking is arranged with the second electrode lay is fixed on the chip sheet The dielectric layer of body top surface, the first electrode layer have first connecting portion and multiple first fourchette electrode portions, the second electrode Layer has the second connecting portion and multiple second fourchette electrode portions with the first connecting portion separately, the first fourchette electrode portion Extend from the first connecting portion towards the second connecting portion, the second fourchette electrode portion is from the second connecting portion towards described First connecting portion extends, and the first fourchette electrode portion and the second fourchette electrode portion are staggered distribution at each interval, It is characterized by: the dielectric layer is made of high-dielectric coefficient semiconductor inorganic materials, and the high-dielectric coefficient semiconductor The dielectric coefficient of inorganic material is between 3.7~80F/m.

2. dielectric particles according to claim 1 manipulate chip, it is characterised in that: the first electrode layer and described second Electrode layer be it is radially inner and outer be arranged at intervals on the chip body, the second connecting portion is annular in shape, and interval is surrounded on institute State first connecting portion radial outside, the second fourchette electrode portion be spaced apart along the second connecting portion inner peripheral from institute It is radial inside towards the first connecting portion projection to state second connecting portion, the first fourchette electrode portion is along the first connecting portion Periphery extends towards the second connecting portion with being spaced apart radially outward.

3. dielectric particles according to claim 1 or 2 manipulate chip, it is characterised in that: the high-dielectric coefficient semiconductor Inorganic material is selected from SiO₂、Si₃N₄、HfO₂And TiO₂。

4. dielectric particles according to claim 1 or 2 manipulate chip, it is characterised in that: the thickness range of the dielectric layer Between 100~300nm.

5. dielectric particles according to claim 4 manipulate chip, it is characterised in that: the high-dielectric coefficient semiconducting inorganic Material is to be fixed on the chip by the way that plating, physical vaporous deposition, chemical vapour deposition technique or rotary coating mode are coating Ontology.

6. dielectric particles according to claim 2 manipulate chip, it is characterised in that: every one first fourchette electrode portion is from institute The extending radially outward and wide strip of first connecting portion is stated, every one second fourchette electrode portion is from the second connecting portion diameter To extend inside and in the triangle of width gradually narrow contracting.