CN217527256U - Virtual staggered electrode micro mixer based on light-induced alternating current seepage principle - Google Patents

Abstract

The utility model relates to a micro-fluidic technical field, the technical problem that solve lie in overcoming current different electroosmosis fluid mixing arrangement and need complicated physics metal electrode's limitation, and provide a virtual crisscross electrode micromixer based on light induction alternating current seepage flow principle, its structure mainly includes the mixed runner of electroosmosis, first sample reagent runner, second sample reagent runner, light guiding layer and signal generator, power amplifier, syringe pump, projecting apparatus and zoom light path etc.. Wherein the first sample reagent and the second sample reagent flow into the first sample reagent flow channel and the second sample reagent flow channel from the first sample reagent inlet and the second sample reagent inlet, respectively, and simultaneously merge into the electroosmotic mixing flow channel. The top and bottom walls of the electroosmosis mixing flow channel are transparent indium tin oxide glass, a light guide layer is continuously deposited on the inner side of the indium tin oxide glass substrate of the top and/or bottom wall of the electroosmosis mixing flow channel by adopting a plasma enhanced chemical vapor deposition method, a low-frequency alternating current signal generated by a signal generator and an amplifier is connected between the two indium tin oxide glass substrates, when a light source vertically irradiates a light guide layer, an optical virtual electrode is projected on the surface of the light guide layer and can generate a non-uniform electric field in the electroosmosis mixing flow channel, so that different fluids in the electroosmosis mixing flow channel generate vortex due to electroosmosis, the vortex forces the two fluids to be mixed, and the mixed fluid finally flows out of a mixed fluid outlet. The purpose of efficiently mixing different fluids can be achieved by adjusting the voltage and the frequency of the signal generator.

Description

Virtual staggered electrode micro mixer based on light-induced alternating current seepage principle

Technical Field

The utility model relates to a micro-fluidic field, in particular to microfluid field of mixing mainly is a light-induced alternating current seepage flow micromixer.

Background

Micro-laboratories in the biochemical applications industry often need to mix different fluids quickly. Conventional macroscopic fluids can be mixed by convection, while the fluids in the microchannels are less effective by diffusion alone due to the lower reynolds number. Therefore, in microsystems, in order to achieve efficient mixing of fluids in microchannels, passive mixing devices relying on geometry and active mixing devices using moving parts or external forces are often used.

The existing passive mixing device mainly depends on an internal complex geometric structure or the treatment of the surface of a channel to realize the mixing of fluid in a micro-channel, and is characterized in that the external power is not needed for driving, but the controllability of the fluid is poor, the fluid is extremely dependent on the geometric structure, and the mixing effect is poor. Most of active mixing devices mostly use moving parts to stir different reagents to realize mixing, the controllability of fluid is strong, the mixing effect is good, the efficiency is high, but the structures of main moving parts are complex and very fragile, the processing and manufacturing are difficult, the cost is higher, and a large amount of external energy is needed to be input, so that the active mixing devices are difficult to apply to harsh experimental environments. An alternative approach is to use external energy such as sound, magnetic or electric fields to achieve mixing perpendicular to the main flow direction of different reagents, and most of them use methods relying on electric fields, such as electroosmotic flow, which have the characteristics of simple structure, no moving parts, and easy integration. However, the electroosmotic flow technology is based on the principle of induced charge electroosmosis, and mainly depends on a physical metal electrode fixed by the electroosmotic flow technology, and how to overcome the above disadvantages, which is complicated to manufacture, expensive to process and difficult to operate, has become one of the goals addressed by the persons skilled in the relevant art.

Disclosure of Invention

An object of the utility model is to overcome current different fluid mixing arrangement and need put into the limitation of complicated physics metal electrode in advance, and provide a photoinduction electroosmotic flow micromixer, it has advantages such as simple structure, low cost and flexible operation at least, only needs the shape through the design facula, and the voltage peak value and the frequency size that adjustment signal generator produced just can control the nature and the position of the virtual electrode that produces.

The technical scheme of the utility model as follows:

the utility model provides a pair of light-induced electroosmotic flow micromixer, the structure mainly includes first sample reagent runner (1), second sample reagent runner (2), electroosmosis mixing flow way (3), light guide layer (4) and signal generator and power amplifier (5).

One end of the electroosmosis mixing flow channel (3) is respectively connected with the first sample reagent flow channel (1) and the second sample reagent flow channel (2), and the other end is provided with a mixed fluid outlet (31).

Further, the electroosmotic mixing flow channel (3) has a length of 200 μm, a width of 20 μm, and a height of 20 μm.

Further, the first sample reagent flow channel (1) and the second sample reagent flow channel (2) have the same size specification, and have a length of 50 μm, a width of 20 μm, and a height of 8.89 μm.

Further, the included angle formed by the first sample reagent flow channel (1) and the second sample reagent flow channel (2) at the electroosmosis mixing flow channel (3) is 60 degrees.

Furthermore, the first sample reagent flow channel (1), the second sample reagent flow channel (2) and the electroosmosis mixing flow channel (3) are of equal width and are located on the same plane, and the material is polydimethylsiloxane or polymethyl methacrylate or silicon or glass or quartz. The top wall and the bottom wall of the electroosmosis mixing flow channel (3) are made of transparent ITO (indium tin oxide) glass plated with the light guide layer (4) through a plasma enhanced chemical vapor deposition method, and the signal generator and the power amplifier (5) can be connected between the two ITO glass due to good light transmission and conductivity of the ITO glass so as to generate an alternating current electric field in the electroosmosis mixing flow channel (3).

Furthermore, the light guide layer (4) is of a multilayer film structure, the length is 200 micrometers, the width is 20 micrometers, the thickness is 2 micrometers, and the material of the light guide layer sequentially comprises heavily doped hydrogenated amorphous silicon with the thickness of 50nm, intrinsic hydrogenated amorphous silicon with the thickness of 1.5 micrometers and silicon carbide with the thickness of 25nm from bottom to top.

Because the hydrogenated amorphous silicon has good photosensitive characteristics, under the non-illumination condition, the hydrogenated amorphous silicon is used as an insulator to occupy more potential difference, so that an electric field in the electroosmosis mixed flow channel (1) is quite weak, but under the illumination condition, the photon-generated carriers increase the local conductivity of the illuminated area of the hydrogenated amorphous silicon, so that the hydrogenated amorphous silicon becomes a good conductor. When light projects light guide layer (4) when, will be in light guide layer (4) overhead projection produces optical pattern (facula), and this is promptly optical virtual electrode (41, 42, 43, 44, 45, 46, 47, 48), and its facula that can produce the projecting apparatus according to the actual demand designs, the utility model discloses a virtual electrode can be in the induced electroosmosis vortex that produces perpendicular to sample reagent mainstream direction in the mixed runner of electroosmosis (3), and then realize the fluidic mixture of two strands of layering sample reagents.

Compared with the prior art, the utility model discloses owing to replace traditional physics metal electrode with the virtual electrode of optics, the event has following advantage:

1. the structure is simple, does not depend on a complex geometric structure, and is directly suitable for a straight channel;

2. due to the silicon carbide film in the photoconductive layer, the hydrolysis phenomenon in the channel can be greatly weakened;

3. the mixing device is simple to manufacture, low in cost and short in period;

4. after the mixing is completed, the functions can be conveniently switched to other functions, so that the integration of multiple functions in the same chip becomes possible, and the method has the characteristic of flexible operation.

The utility model has the characteristics of reasonable in design, simple structure, easily processing, flexible operation etc, therefore, have fine using value widely.

Drawings

The present invention will be further explained with reference to the accompanying drawings. It is noted that, in accordance with standard practice in the industry, the drawings

The various features of (a) are not drawn to scale and, in fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a schematic structural diagram of a virtual staggered electrode micro-mixer based on the principle of light-induced alternating current seepage;

fig. 2 is a schematic view of the structure of the light guiding layer (4);

FIG. 3 is a graph of the velocity at the center cross section of the flow channel at 0.15s and a flow chart;

FIG. 4A is a vector diagram of the longitudinal section velocity of the virtual electrode (41) at 0.8 s;

FIG. 4B is a vector diagram of the longitudinal section velocity of the virtual electrode (42) at 0.8 s;

FIG. 5 is a graph of channel concentration at 0.8 s.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments. However, it is to be understood that

The embodiments provide many applicable concepts that can be embodied in a wide variety of specific contexts. The embodiments discussed and disclosed are merely illustrative and are not intended to limit the scope of the present invention.

Also, spatially relative terms, such as central, longitudinal, lateral, upper, lower, front, rear, left, right, top, bottom, inner, outer, vertical, horizontal, surface, and the like, are used for ease of explaining the relationship of one element or feature to another element or feature in the figures. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. These devices may also be rotated (e.g., by 90 degrees or to other orientations) and the spatially relative descriptors used herein interpreted accordingly. Furthermore, the terms first, second, third and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

It should be noted that unless expressly specified or limited otherwise, the terms mounted, connected, coupled, and the like are to be construed broadly and include, for example, fixed connections, removable connections, and integral connections; can be mechanically or electrically connected; either directly or through an intermediary, or internally connected between two elements or features. The specific meaning of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

As shown in the attached figure 1, the structure of the photo-induced electroosmotic flow micro mixer provided by the present invention mainly comprises a first sample reagent flow channel (1), a second sample reagent flow channel (2), an electroosmotic mixing flow channel (3), a photoconductive layer (4), a signal generator and a power amplifier (5)

One end of the electroosmosis mixing flow channel (3) is respectively connected with the first sample reagent flow channel (1) and the second sample reagent flow channel (2), and the other end is provided with a mixed fluid outlet (31). The first sample reagent flow channel (1) and the second sample reagent flow channel (2) are arranged in a Y shape with the electroosmosis mixing flow channel (3), and the included angle is 60 degrees, but the invention is not limited to the above. The end part of the first sample reagent flow channel (1) is provided with a first sample reagent inlet (11), the end part of the second sample reagent flow channel (2) is provided with a second sample reagent inlet (21), and the first sample reagent and the second sample reagent respectively flow into the first sample reagent flow channel (1) and the second sample reagent flow channel (2) through the first sample reagent inlet (11) and the second sample reagent inlet (21) under the action of external injection pump pressure and simultaneously flow into the electroosmosis mixing flow channel (3).

Wherein the flow rates of the first sample reagent and the second sample reagent are equal and are both 0.2 mm/s. The solute concentration of the first sample reagent is 1mol/m ³ Solute concentration of the second sample reagentThe degree is 0mol/m ³ . The first sample reagent flow channel (2) and the second sample reagent flow channel (3) are identical in size and specification, and are 50 micrometers in length, 20 micrometers in width and 20 micrometers in height. The electroosmosis mixing flow channel (3), the first sample reagent flow channel (1) and the second sample reagent flow channel (2) are equal in width and are located on the same plane. The electroosmotic mixing flow channel (3) has a length of 200 μm, a width of 20 μm and a height of 20 μm.

In order to generate an alternating current electric field in the electroosmotic mixed flow channel (3), the top of the electroosmotic mixed flow channel (1) is required,

The bottom walls are made of transparent ITO glass, and the ITO glass has good light transmittance and conductivity, so that electric signals can be loaded on the surfaces of the top wall and the bottom wall of the electroosmosis mixing flow channel (3), namely, the edges of the two ITO glass on the same side are subjected to reactive ion etching to be connected with copper wires, so that the signal generators (5) can be connected to the signal generators for providing voltage signals with certain amplitude and frequency, the peak value of alternating voltage is 1V, and the frequency is 5Hz, but the invention is not limited to the peak value and the frequency.

The electroosmosis mixing flow channel (3), the first sample reagent flow channel (1) and the second sample reagent flow channel (2) can be synchronously designed and manufactured by Micro-Electro-Mechanical System (MEMS) micromachining technology, the electroosmosis mixing flow channel is an industrial technology which integrates microelectronic technology and Mechanical engineering, and the operating range is in a micrometer range.

Specifically, the channels such as the electroosmotic mixing channel (3), the first sample reagent channel (1), and the second sample reagent channel (2) can also be manufactured by standard technologies such as a template hot pressing method or a template casting method.

FIG. 2 is a schematic structural diagram of the photoconductive layer (4), in order to form a microelectrode, 50nm thick heavily doped hydrogenated amorphous silicon (51), 1.5 μm thick intrinsic hydrogenated amorphous silicon (50) and 25nm thick silicon carbide (49) are continuously deposited on the inner side surface of the ITO glass substrate of the top and/or bottom wall of the electroosmosis mixing flow channel (3) by plasma enhanced chemical vapor deposition, and the multilayer film structure is the photoconductive layer (4). Wherein the light guiding layer (4) has a length of 200 μm and a width of 20 μm.

It should be noted that, the light guide layer (4) is deposited on the inner side surface of the top and/or bottom ITO glass substrate of the electroosmotic mixing flow channel (3), that is, the light guide layer (4) is deposited on the inner side surface of the top and bottom ITO glass substrate of the electroosmotic mixing flow channel (3), or the light guide layer (4) is deposited only on the inner side surface of the top ITO glass substrate of the electroosmotic mixing flow channel (3), or the light guide layer is deposited only on the inner side surface of the bottom ITO glass substrate of the electroosmotic mixing flow channel (3). (4) The requirements of the invention on the light guide layer (4) can be realized in all three ways.

Because the intrinsic hydrogenated amorphous silicon (50) has good photosensitive characteristics, under the non-lighting condition, the hydrogenated amorphous silicon is used as an insulator to occupy more potential difference, so that an electric field in the electroosmosis mixing flow channel (3) is quite weak, but under the lighting condition, electron hole pairs (photocarriers) increase the local conductivity of a lighting area of the hydrogenated amorphous silicon to form a good conductor, so that different partial pressures are generated in the lighting area and a dark area, and further a non-uniform electric field is generated in the electroosmosis mixing flow channel (3), light spots (optical patterns) at the lighting area are optical virtual electrodes (41, 42, 43, 44, 45, 46, 47, 48), and the electrodes can induce and generate eddy currents vertical to the main flow direction of a sample reagent in the electroosmosis mixing flow channel (3) under the electroosmosis effect, so that the mixing of two layered sample reagent fluids is realized. Meanwhile, silicon carbide (49) can weaken a hydrolysis phenomenon occurring in the electroosmotic mixing flow channel (3), and heavily doped hydrogenated amorphous silicon (51) can reduce contact resistance between the ITO glass substrate and the intrinsic hydrogenated amorphous silicon.

Fig. 3 is a cross-sectional velocity and flow chart of the center of the flow channel at 0.15s, with the scale indicating the magnitude of the velocity of the fluid in the flow channel, and the flow lines in the chart indicating the movement of a number of fluid particles in the flow field at 0.15 s. It can be seen that the two flows in the flow channel are mixed to a greater extent by the action of the electroosmotic flow generated by the virtual interleaved electrodes.

Fig. 4A is a vector diagram of the longitudinal section velocity of the virtual electrode (41) at 0.8s, fig. 4B is a vector diagram of the longitudinal section velocity of the virtual electrode (42) at 0.8s, and the scales indicate the velocity of the fluid in the flow channel. It can be seen from the figure that the electron-hole pairs (photo-generated carriers) generated by illumination increase the local conductivity of the illuminated area on the photoconductive layer (4), so that a non-uniform electric field is generated in the electroosmotic mixed flow channel (3), and the electric field generates large disturbance to the flow of the fluid. On one hand, the staggered virtual electrode arrangement generates rotating vortex flows between two flows, so that the convection effect of the flow velocity of the flows between the vortex flows is greatly enhanced. On the other hand, due to the action of the signal generator and the power amplifier, an alternating voltage signal with the frequency of 5Hz and the peak voltage of 1V is generated, so that the flow speed of the fluid is rapidly increased among the eddy currents, and the mixing speed of the fluid is increased. The eddy current is generated because a large potential gradient is provided between the opposite optical virtual electrodes (41, 42, 43, 44, 45, 46, 47, 48), and the potential gradient proves that the generated electric field force can be applied to the fluid in the flow channel, so that the wall surface of the flow channel generates electroosmotic velocity, and further generates electroosmotic flow eddy which plays a good role in mixing the fluid.

Fig. 5 is a graph of the channel concentration at 0.8s, with a scale indicating the concentration of fluid in the channel. As can be seen from the figure, the two flows with different concentrations achieve better mixing effect after a period of time, and the mixing efficiency can reach 98%.

With the above embodiments, those skilled in the art can easily realize the present invention. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the basis of the disclosed embodiments, a person skilled in the art can combine different technical features at will, thereby implementing different technical solutions. Except for the technical features described in the specification, the method is known by the technical personnel in the field.

Claims (8)

1. A virtual staggered electrode micromixer based on the principle of light-induced alternating current seepage comprises a first sample reagent flow channel (1), a second sample reagent flow channel (2), an electroosmosis mixing flow channel (3), a photoconductive layer (4), optical virtual electrodes (41, 42, 43, 44, 45, 46, 47, 48) and a signal generator and power amplifier (5), and is characterized in that: two fluids with different concentrations respectively flow into the electroosmosis mixing flow channel (3) from the first sample reagent flow channel (1) and the second sample reagent flow channel (2), a light guide layer (4) is attached to the bottom end of the electroosmosis mixing flow channel (3), the anode of a signal generator and a power amplifier (5) is connected to the top end of the electroosmosis mixing flow channel (3), and the cathode of the signal generator and the power amplifier (5) is connected to the bottom end of the light guide layer (4).

2. The virtual interleaved electrode micromixer based on the light-induced alternating current seepage principle of claim 1, which is characterized in that: the electroosmosis mixing flow channel (3) is 200 μm in length, 20 μm in width and 20 μm in height.

3. The virtual interleaved electrode micromixer based on the light-induced alternating current seepage principle of claim 1, which is characterized in that: and the inner side surface of the indium tin oxide glass on the top and/or bottom wall of the electroosmosis mixing flow channel (3) is coated with the photoconductive layer (4) by plasma enhanced chemical vapor deposition.

4. The virtual interleaved electrode micromixer based on the light-induced alternating current seepage principle of claim 1, which is characterized in that: the light guide layer (4) is of a multilayer film structure, the length of the light guide layer is 200 micrometers, the width of the light guide layer is 20 micrometers, and the light guide layer is made of heavily doped hydrogenated amorphous silicon with the thickness of 50nm, intrinsic hydrogenated amorphous silicon with the thickness of 1.5 micrometers and silicon carbide with the thickness of 25nm from outside to inside in sequence.

5. The virtual interleaved electrode micromixer based on light induced Alternating Current (AC) seepage principle according to claim 1, characterized in that: the light is focused and reflected to the photoconductive layer (4) through an optical lens and a plane mirror by a common projector light source, the optical virtual electrodes (41, 42, 43, 44, 45, 46, 47, 48) are generated by projection on the surface of the photoconductive layer (4) under the illumination condition, the length and the width of each optical virtual electrode (41, 42, 43, 44, 45, 46, 47, 48) are 10 mu m, and the distance between the electrodes is 10 mu m.

6. The virtual interleaved electrode micromixer based on the light-induced alternating current seepage principle of claim 1, which is characterized in that: the end part of the first sample reagent flow channel (1) is provided with a first sample reagent inlet (11), the end part of the second sample reagent flow channel (2) is provided with a second sample reagent inlet (21), two streams of reagents with different concentrations are pumped into the inlets of the two flow channels by an injection pump, one end of the electroosmosis mixing flow channel (3) is respectively connected with the first sample reagent flow channel (1) and the second sample reagent flow channel (2), and the other end of the electroosmosis mixing flow channel is provided with a mixed fluid outlet (31).

7. The virtual interleaved electrode micromixer based on light induced Alternating Current (AC) seepage principle according to claim 1, characterized in that: the first sample reagent flow channel (1) and the second sample reagent flow channel (2) are identical in size and specification, the lengths of the first sample reagent flow channel and the second sample reagent flow channel are both 50 micrometers, the widths of the first sample reagent flow channel and the second sample reagent flow channel are both 20 micrometers, the heights of the first sample reagent flow channel and the second sample reagent flow channel are both 8.89 micrometers, and an included angle formed by the first sample reagent flow channel (1) and the second sample reagent flow channel (2) at the electroosmosis mixing flow channel (3) is 60 degrees.

8. A virtual staggered electrode micro mixer based on light-induced alternating current seepage principle is characterized in that: the first sample reagent flow channel (1), the second sample reagent flow channel (2) and the electroosmosis mixing flow channel (3) are equal in width and located on the same plane, and the materials of the first sample reagent flow channel, the second sample reagent flow channel and the electroosmosis mixing flow channel are polydimethylsiloxane or polymethyl methacrylate.

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