An optical fiber light microfluidic integrated device

Abstract

The utility model provides a kind of optical fiber light microflow integrated device, including double-channel micro-pipe and the first single-mode optical fiber and second single-mode optical fiber respectively fused at its two ends, three form light beam transmission path after being connected, the free end of first single-mode optical fiber is connected to broadband light source for providing incident light;The free end of second single-mode optical fiber is connected to spectrometer for receiving and analyzing output light;Double-channel micro-pipe is equipped with two channels that are parallel to each other and position symmetric, and two channels do not interfere with light beam transmission path, the inlet end of two channels is all sealed connection with micro-injection pump, and outlet end is all pipeline connection to waste liquid pool.The utility model forms light beam transmission path by double-channel micro-pipe and the first single-mode optical fiber and second single-mode optical fiber respectively fused at its two ends, realizes the efficient, stable integration of optical path and multi-path microfluid, solves the problem of traditional device coupling difficulty, unstable connection, single function, low detection efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of fiber optic sensing and microfluidics technology, and in particular relates to an integrated fiber optic microfluidics device. Background Technology

[0002] Microfluidics, with its ability to precisely manipulate fluids at the microliter and even nanoliter levels, shows immense potential in fields such as biochemical analysis, disease diagnosis, and environmental monitoring. Fiber optic sensing technology offers advantages such as resistance to electromagnetic interference, high sensitivity, and remote operation. Combining these two technologies, "optical microfluidics" enables in-situ, real-time, and highly sensitive optical detection of trace fluids, representing a cutting-edge direction in analytical science. Most existing optical microfluidic devices employ planar waveguides or fiber end-to-end connections to microchannel chips. Planar waveguide devices suffer from complex fabrication processes, low coupling efficiency with external optical fibers, and high insertion loss. Fiber end-to-end connections, on the other hand, present challenges such as alignment difficulties, poor connection stability, and susceptibility to leakage, and typically only allow for single-channel detection, limiting functionality and hindering the manipulation of multiple parameters or complex flow paths. Microstructured optical fibers, especially those with multiple air channels, can themselves serve as natural microfluidic channels. However, efficiently and reliably introducing and extracting liquids into these micrometer-scale channels, and achieving low-loss, stable connections with standard single-mode optical fibers, remains a key challenge hindering their practical application. Existing technologies typically rely on complex precision fixtures or cumbersome capillary bonding, resulting in bulky devices with low reliability and difficulty in achieving independent multi-channel sample introduction and detection. Utility Model Content

[0003] In view of this, the present invention aims to propose an integrated fiber optic microfluidic device to solve at least one of the above-mentioned problems. The present invention forms a beam transmission path through a dual-channel microtube and a first single-mode fiber and a second single-mode fiber respectively fused at both ends. The dual-channel microtube has two parallel and symmetrical channels, and the two channels do not interfere with the beam transmission path, realizing efficient and stable integration of the optical path and multiple microfluidics, and solving the problems of difficult coupling, unstable connection, single function and low detection efficiency of traditional devices.

[0004] To achieve the above objectives, the technical solution of this utility model is implemented as follows: An integrated fiber-optic microfluidic device includes a dual-channel microtube and a first single-mode fiber and a second single-mode fiber fused to its two ends, respectively. The three components are connected to form a beam transmission path. The fusion joint between the dual-channel microtube and the first single-mode fiber forms a first interface, and the fusion joint between the dual-channel microtube and the second single-mode fiber forms a second interface. The free end of the first single-mode fiber is connected to a broadband light source for providing incident light. The free end of the second single-mode fiber is connected to a spectrometer for receiving and analyzing the output light. The dual-channel microtube has two parallel and symmetrically positioned channels that do not interfere with the beam transmission path. The inlet ends of both channels are sealed to a micro-injection pump, and the outlet ends of both channels are piped to a waste liquid tank.

[0005] Furthermore, the dual-channel microchannel has a cylindrical structure, and the outer diameters of the first single-mode fiber, the second single-mode fiber, and the dual-channel microchannel are the same.

[0006] Furthermore, the length of the dual-channel microchannel is 200 micrometers, and the inner diameter of each channel ranges from 40 to 45 micrometers.

[0007] Furthermore, the two channels have the same cross-section, which is either circular or elliptical.

[0008] Furthermore, the two channels are a first microfluidic channel and a second microfluidic channel, respectively. The first microfluidic channel has a symmetrical first inlet and a first outlet at both ends, and the second microfluidic channel has a symmetrical second inlet and a second outlet at both ends. The included angle between the first inlet, the first outlet, the second inlet, the second outlet and the axis of the dual-channel microtube is 30°-80°.

[0009] Furthermore, the dual-channel microchannel is a one-piece molded structure.

[0010] Furthermore, the fusion splice of the dual-channel microtube and the first single-mode optical fiber is sleeved on the first connecting tube, and the two ends of the first connecting tube are sealed with UV glue to the fusion splice and the connecting tube of the micro-injection pump. The fusion splice of the dual-channel microtube and the second single-mode optical fiber is fixedly sleeved on the second connecting tube, and the two ends of the second connecting tube are sealed with UV glue to the fusion splice and the connecting tube of the waste liquid pool.

[0011] Furthermore, the inner diameter of both the first connecting pipe and the second connecting pipe is 1 mm.

[0012] Furthermore, both the first and second single-mode optical fibers are standard single-mode optical fibers with a length of 150 micrometers, an outer diameter of 125 micrometers, and an inner diameter of 9 micrometers.

[0013] Furthermore, the dual-channel microchannel is made of transparent glass or quartz.

[0014] Compared with existing technologies, the fiber optic microfluidic integrated device of this invention has the following advantages: (1) This utility model forms a beam transmission path by means of a dual-channel microtube and a first single-mode fiber and a second single-mode fiber respectively fused at both ends. The dual-channel microtube is provided with two parallel and symmetrical channels, and the two channels do not interfere with the beam transmission path. This realizes the efficient and stable integration of the optical path and multiple microfluids, and solves the problems of difficult coupling, unstable connection, single function and low detection efficiency of traditional devices.

[0015] (2) This utility model is achieved by standard single-mode fiber fusion splicing, with low connection loss and high mechanical strength; the structure is extremely compact, avoiding complex alignment and packaging processes; the unique side corner design of the dual-channel microchannel provides inlet and outlet for two independent microfluidic channels respectively, so that the two microfluidic channels can be simultaneously introduced into the liquid to be tested, which greatly improves the detection efficiency.

[0016] (3) This application utilizes the characteristics of microstructured optical fiber, which can confine the light field well in the air channel or in the quartz matrix around it, and interact strongly with the liquid to be tested in the microfluidic channel, thereby obtaining a highly sensitive detection signal. Attached Figure Description

[0017] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings: Figure 1 This is a schematic diagram of the fiber optic microfluidic integrated device described in an embodiment of the present invention; Figure 2 This is a schematic diagram of the beam transmission path described in an embodiment of the present invention; Figure 3 This is a schematic diagram of the dual-channel microtube circuit described in an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the working principle of the fiber optic microfluidic integrated device described in this embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1-First single-mode optical fiber; 2-Dual-channel microtube; 21-First microfluidic channel; 211-First inlet; 212-First outlet; 22-Second microfluidic channel; 221-Second inlet; 222-Second outlet; 3-Second single-mode optical fiber; 4-First connecting tube; 5-Second connecting tube; 6-Broadband light source; 7-Spectrometer; 8-First interface; 9-Second interface; 10-Micro-injection pump; 11-Waste liquid tank; A-Optical signal path; B-Flow path of the liquid to be tested in the first microfluidic channel; C-Flow path of the liquid to be tested in the second microfluidic channel. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] A fiber optic microfluidic integrated device, such as Figures 1 to 4 As shown, the device includes a dual-channel microtube 2 and a first single-mode fiber 1 and a second single-mode fiber 3 fused to its two ends. The three components are connected to form a beam transmission path. The fusion joint between the dual-channel microtube 2 and the first single-mode fiber 1 forms a first interface 8, and the fusion joint between the dual-channel microtube 2 and the second single-mode fiber 3 forms a second interface 9. The free end of the first single-mode fiber 1 is connected to a broadband light source 6 for providing incident light. The free end of the second single-mode fiber 3 is connected to a spectrometer 7 for receiving and analyzing the output light. The dual-channel microtube 2 has two parallel and symmetrically positioned channels that do not interfere with the beam transmission path. The inlet ends of both channels are sealed to a micro-injection pump 10, and the outlet ends are piped to a waste liquid tank 11.

[0024] This application achieves efficient and stable integration of optical paths and multi-channel microfluidics through a dual-channel microtube and a first single-mode fiber and a second single-mode fiber fused to both sides, solving the problems of difficult coupling, unstable connection and single function of traditional devices.

[0025] In some embodiments, the micro-injection pump 10 is sealed to the inlet end of the two channels via a plastic hose; the waste liquid tank 11 is sealed to the outlet end of the two channels via a plastic hose.

[0026] In some embodiments, the first single-mode fiber 1 and the second single-mode fiber 3 are both standard single-mode fibers with a length of 150 micrometers, an outer diameter of 125 micrometers, and an inner diameter of 9 micrometers. The standard single-mode fiber transmits only one fundamental mode, which is used to excite the dual-channel microchannel 2. This ensures that the light entering the sensing area is a single, stable mode, and provides an ideal optical channel for achieving high-sensitivity and high-precision micro-liquid spectral analysis.

[0027] In some embodiments, the dual-channel microchannel 2 is a cylindrical structure, and the outer diameters of the first single-mode fiber 1, the second single-mode fiber 3, and the dual-channel microchannel 2 are the same, which facilitates fusion splicing between the three.

[0028] In some embodiments, the dual-channel microchannel 2 is made of transparent glass or quartz, which facilitates observation of the internal liquid flow and also facilitates its splicing with the first single-mode optical fiber 1 and the second single-mode optical fiber 3 on both sides.

[0029] In some embodiments, the length of the dual-channel microchannel 2 is 200 micrometers, and the inner diameter of each channel ranges from 40 to 45 micrometers, which can maximize the flow resistance of the liquid to be tested through the dual-channel microchannel.

[0030] In some embodiments, the two channels have the same cross-section, which is either circular or elliptical. The identical cross-section ensures that the light beam has the same transmission path between the two channels without any difference. The circular or elliptical cross-section also ensures that the liquid passes through without any dead corners, facilitating subsequent cleaning and reuse.

[0031] In some embodiments, the two channels are a first microfluidic channel 21 and a second microfluidic channel 22, respectively. The first microfluidic channel 21 has a symmetrical first inlet 211 and a first outlet 212 at its two ends, and the second microfluidic channel 22 has a symmetrical second inlet 221 and a second outlet 222 at its two ends. The angle between the first inlet 211, the first outlet 212, the second inlet 221, the second outlet 222 and the axis of the dual-channel microtube 2 is 30°-80°, preferably 50°. This structure allows the light field to be well confined in or around the dual-channel microtube 2 matrix in the two channels, and to interact strongly with the liquid to be tested in the channels, thereby obtaining a highly sensitive detection signal.

[0032] In some embodiments, the dual-channel microchannel 2 is a one-piece molded structure, which is simple, easy to manufacture, and thus reduces economic costs.

[0033] In some embodiments, the axis of the dual-channel microtube 2 and the fusion splice of the first single-mode optical fiber 1 are sleeved on the first connecting tube 4, and the two ends of the first connecting tube 4 are sealed with UV glue to the fusion splice and the connecting tube of the micro-injection pump 10. The axis of the dual-channel microtube 2 and the fusion splice of the second single-mode optical fiber 3 are fixedly sleeved on the second connecting tube 5, and the two ends of the second connecting tube 5 are sealed with UV glue to the fusion splice and the connecting tube of the waste liquid pool to prevent liquid leakage.

[0034] In some embodiments, the broadband light source 6 is a 905nm ASE broadband light source; the spectrometer 7 is an Advantage 532. The micro-injection pump 10 is a Lange LSP01-2A integrated injection pump. Its integrated design saves space. Unlike the separate design of "pump head + controller", the integrated design integrates all control units and drive units into a compact body. This greatly saves laboratory workbench space, simplifies wiring, and makes movement and placement very convenient.

[0035] In some embodiments, the inner diameter of the first connecting tube 4 and the second connecting tube 5 is 1 mm. The two connecting tubes are easy to hold, align and fix, which greatly reduces the difficulty of operation and protects the delicate dual-channel microchannel 2 structure, making the device more robust and durable. At the same time, it significantly reduces fluid resistance. The 1 mm diameter can also encapsulate the optical fiber segment and the plastic tubing at the same time, making it easier for liquid to be pumped into the microchannel.

[0036] Working principle of a fiber optic microfluidic integrated device: The optical path is emitted from a broadband light source 6, passes sequentially through a first single-mode fiber 1, a dual-channel microtube segment 2, and a second single-mode fiber 3, and is finally received by a spectrometer 7, forming a complete transmission measurement system. When the light emitted from the broadband light source 6 is coupled from the first single-mode fiber 1 into the dual-channel microtube 2, at the first interface 8, its optical field is strongly modulated by the air holes (first liquid inlet 211 and second liquid inlet 221) on both sides of the core of the first single-mode fiber 1, exciting two propagation modes with an effective refractive index difference (or considered as two spatially separated guide waves). Therefore, the light is split into three beams at the first interface 8: one beam penetrates into the solid core of the dual-channel microtube 2, one beam enters the first microfluidic channel 21, and one beam enters the second microfluidic channel 22. These three beams accumulate phase differences during transmission due to their different phase constants. When they merge again at the second interface 9, interference occurs, and the interference pattern strongly depends on the phase difference accumulated during transmission. When the refractive index of the liquid in the first and second microfluidic channels changes, it causes a change in the optical path difference. This change directly leads to a shift in the interference fringes in the transmission spectrum. By monitoring and calculating the shift of the fringes in real time using spectrometer 7, highly sensitive, real-time measurement of changes in the refractive index of the liquid under test can be achieved.

[0037] A method of using a fiber optic microfluidic integrated device: like Figure 4 As shown in Figure A, when the broadband light source 7 is turned on, the light passes sequentially through the first single-mode fiber 1, the dual-channel microchannel 2, and the second single-mode fiber 3, and is finally received by the spectrometer 7, which will display a series of clear interference fringes. Figure 4 As shown in B and C, liquid injection: The sample liquid to be tested is pumped into the first capillary tube 4 through the plastic tubing using the micro-injection pump 10, so that the sample liquid to be tested can smoothly enter the first inlet 211 and the second inlet 221, flow through the first microfluidic channel 21 and the second microfluidic channel 22, and then be discharged from the first outlet 212 and the second outlet 222 respectively, and flow into the waste liquid pool 11 through the pipeline.

[0038] The optical path of this application is achieved through standard single-mode fiber fusion splicing, resulting in low connection loss and high mechanical strength. The structure is extremely compact, avoiding complex alignment and packaging processes. The unique four-corner side design provides inlet and outlet for two independent microfluidic channels, allowing the two microfluidic channels to simultaneously flow with the liquid to be tested, greatly improving detection efficiency. Utilizing the characteristics of microstructured optical fibers, the optical field can be well confined in the air channel or the surrounding quartz matrix, interacting strongly with the liquid to be tested within the microfluidic channel, thereby obtaining a highly sensitive detection signal.

[0039] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A fiber optic microfluidic integrated device, characterized in that: The device includes a dual-channel microtube and a first single-mode fiber and a second single-mode fiber fused to its two ends. The three components are connected to form a beam transmission path. The fusion joint between the dual-channel microtube and the first single-mode fiber forms a first interface, and the fusion joint between the dual-channel microtube and the second single-mode fiber forms a second interface. The free end of the first single-mode fiber is connected to a broadband light source for providing incident light, and the free end of the second single-mode fiber is connected to a spectrometer for receiving and analyzing the output light. The dual-channel microtube has two parallel and symmetrically positioned channels that do not interfere with the beam transmission path. The inlet ends of both channels are sealed to a micro-injection pump, and the outlet ends are piped to a waste liquid tank.

2. The fiber optic microfluidic integrated device according to claim 1, characterized in that: The dual-channel microtube has a cylindrical structure, and the outer diameters of the first single-mode fiber, the second single-mode fiber, and the dual-channel microtube are the same.

3. The fiber optic microfluidic integrated device according to claim 1, characterized in that: The dual-channel microchannel is 200 micrometers long, and the inner diameter of each channel ranges from 40 to 45 micrometers.

4. The fiber optic microfluidic integrated device according to claim 1, characterized in that: The two channels have the same cross-section, which is either circular or elliptical.

5. The fiber optic microfluidic integrated device according to claim 1, characterized in that: The two channels are a first microfluidic channel and a second microfluidic channel. The first microfluidic channel has a symmetrical first inlet and a first outlet at both ends, and the second microfluidic channel has a symmetrical second inlet and a second outlet at both ends. The included angle between the first inlet, the first outlet, the second inlet, the second outlet and the axis of the dual-channel microtube is 30°-80°.

6. The fiber optic microfluidic integrated device according to claim 1, characterized in that: The dual-channel microchannel is a one-piece molded structure.

7. The fiber optic microfluidic integrated device according to claim 1, characterized in that: The axis of the dual-channel microtube and the fusion splice of the first single-mode fiber are sleeved on the first connecting tube, and the two ends of the first connecting tube are sealed with UV glue to the fusion splice and the connecting tube of the micro-injection pump. The axis of the dual-channel microtube and the fusion splice of the second single-mode fiber are fixedly sleeved on the second connecting tube, and the two ends of the second connecting tube are sealed with UV glue to the fusion splice and the connecting tube of the waste liquid tank.

8. The fiber optic microfluidic integrated device according to claim 1, characterized in that: The inner diameter of both the first and second connecting pipes is 1 mm.

9. The fiber optic microfluidic integrated device according to claim 1, characterized in that: Both the first and second single-mode fibers are standard single-mode fibers, with a length of 150 micrometers, an outer diameter of 125 micrometers, and an inner diameter of 9 micrometers.

10. The fiber optic microfluidic integrated device according to claim 1, characterized in that: The dual-channel microtubes are made of transparent glass or quartz.

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