CN112481721A - Microfluidic spinning device, linear type core-shell structure conductive fiber, and preparation method and application thereof - Google Patents

Abstract

Translated fromChinese

本发明公开了一种微流控纺丝装置、直线型核壳结构导电纤维及其制备方法和应用，该方法基于共流的微流控纺丝装置，通过将壳层溶液和核层溶液分别导入内相毛细管和中间相毛细管中，得到呈现层流状态的核壳结构纤维前体，再利用外相固化溶液对纤维前体进行迅速的固化，从而顺利保持纤维的核壳结构；通过调整纤维各相流速对纤维的壁厚进行精密调整，进而实现导电纤维的形貌调控，制备工艺简单、成本低廉，适合大规模生产；直线型核壳结构导电纤维以MXene水溶液作为核层，生物相容性较好的收缩性藻酸盐水凝胶材料为鞘层，在保证良好核壳结构的同时，赋予纤维卓越的导电性能和光热收缩性能，从而可以应用到对外界光热刺激进行响应的柔性电子器件上。

The invention discloses a microfluidic spinning device, a linear core-shell structure conductive fiber and a preparation method and application thereof. The method is based on a co-flow microfluidic spinning device. Introduce into the inner phase capillary and the mesophase capillary to obtain a core-shell fiber precursor in a laminar flow state, and then use the outer phase curing solution to rapidly solidify the fiber precursor, so as to maintain the core-shell structure of the fiber smoothly; The phase flow rate precisely adjusts the wall thickness of the fiber, and then realizes the shape control of the conductive fiber. The preparation process is simple, the cost is low, and it is suitable for large-scale production; the linear core-shell structure conductive fiber uses the MXene aqueous solution as the core layer, which is biocompatible. The better shrinkable alginate hydrogel material is the sheath layer, which not only ensures a good core-shell structure, but also endows the fiber with excellent electrical conductivity and photothermal shrinkage properties, so that it can be applied to flexibility in response to external photothermal stimuli. on electronic devices.

Description

Microfluidic spinning device, linear type core-shell structure conductive fiber, and preparation method and application thereof

Technical Field

The invention relates to the technical field of biological materials, in particular to a microfluidic spinning device, a linear type core-shell structure conductive fiber, and a preparation method and application thereof.

Background

In recent years, electrically conductive hydrogels have been widely used in various applications including pressure sensors, temperature sensors, supercapacitors, soft robots, etc., and are considered to be the most promising materials for flexible electronic systems. Nowadays, various conductive elements have been combined with hydrogels and exhibit excellent conductive properties and mechanical properties. Among these conductive elements, MXene, a two-dimensional early transition metal carbide/carbonitride newly discovered in 2011, has been widely assembled with two-dimensional materials and even three-dimensional materials due to its excellent electrical and thermal conductivity and excellent hydrophilic properties, and is applied to various biomedical engineering fields. However, assembly of MXenes with one-dimensional hydrogel fibers still faces significant challenges due to the inherent two-dimensional structure of MXene. Moreover, most of the existing preparation methods are too simple and rough, and the morphology cannot be accurately controlled, so that the finally obtained conductive material has poor conductivity.

The micro-fluidic spinning is a common technology for preparing one-dimensional fibers, can accurately control micro-scale fluid, and has the advantages of small device volume, controllable liquid flow, easiness in control and the like. By adjusting a micro-channel device of a micro-fluidic spinning technology, functional fiber carriers with various shapes and structures, particularly functional fiber carriers with a core-shell structure, can be controllably prepared, can realize the encapsulation of chemical and biological samples with different properties, and has been widely applied to the field of biomedical engineering. However, the MXene conductive core-shell structure fiber generated by the microfluidic spinning technology still deserves further exploration and development in the field of flexible conductive systems, and particularly has application value in photo-thermal-resistance response.

Disclosure of Invention

Aiming at the defects of the existing research on the assembly of MXene and fibers and the preparation of flexible conductive elements by microfluidic spinning, the invention provides a method for preparing linear type core-shell structure conductive fibers with good conductivity and photo-thermal shrinkage performance based on a microfluidic spinning technology and application of the prepared linear type core-shell structure conductive fibers in a flexible electronic system.

In order to achieve the technical purpose, the technical scheme adopted by the invention is as follows: a micro-fluidic spinning device comprises an internal phase capillary tube, an intermediate phase capillary tube, an observation capillary tube, an external phase capillary tube, an internal phase liquid inlet device, an intermediate phase liquid inlet device and an external phase liquid inlet device, wherein the intermediate phase capillary tube is coaxially sleeved at the rear part of the internal phase capillary tube, the external phase capillary tube is coaxially sleeved at the rear part of the intermediate phase capillary tube, the observation capillary tube is positioned at a joint of the intermediate phase capillary tube and the external phase capillary tube, the internal phase capillary tube is connected with the internal phase liquid inlet device to form an internal phase fluid circulation pipeline, the intermediate phase capillary tube is connected with the intermediate phase liquid inlet device to form an intermediate phase fluid circulation pipeline, and the external phase capillary tube is connected with.

Further, internal phase inlet means, mesophase inlet means and external phase inlet means structure are the same, all include syringe pump and syringe connection syringe needle, and the syringe pump passes through the pipe and is connected the syringe needle switch-on with the syringe, internal phase inlet means, mesophase inlet means and external phase inlet means's syringe connection syringe needle communicates with internal phase capillary, mesophase inlet means and external phase inlet means respectively through the pipe, and the flow direction of internal phase fluid, mesophase fluid and external phase fluid is the same.

Furthermore, the inner phase capillary tube, the middle phase capillary tube, the observation capillary tube and the outer phase capillary tube are all glass capillary tubes, the inner diameter of the inner phase capillary tube is 1/3-1/2 of the inner diameter of the middle phase capillary tube, the inner diameter of the middle phase capillary tube is 1/4-3/4 of the inner diameter of the outer phase capillary tube, and the joints of the inner phase capillary tube, the middle phase capillary tube, the observation capillary tube and the outer phase capillary tube are sealed by transparent epoxy resin.

Furthermore, the outflow port of the inner phase capillary tube is in a pointed cone shape, and the inner diameter of the inner phase capillary tube is 100-200 mu m; the outflow port of the intermediate phase capillary tube is in a pointed cone shape, and the inner diameter of the intermediate phase capillary tube is 250-350 mu m; the outflow port of the external phase capillary is circular, and the inner diameter of the external phase capillary is 800 μm; the observation capillary was a square capillary.

The invention also provides a preparation method of the linear type core-shell structure conductive fiber, which is prepared by adopting the microfluidic spinning device and comprises the following steps:

s1, assembling the microfluidic spinning device: coaxially assembling an inner phase capillary tube into an intermediate phase capillary tube, coaxially assembling the intermediate phase capillary tube into an outer phase capillary tube, and observing that the capillary tube is sleeved at the interface of the intermediate phase capillary tube and the outer phase capillary tube, wherein the inner diameter of the inner phase capillary tube is 100-200 mu m, the inner diameter of the intermediate phase capillary tube is 250-350 mu m, and the inner diameter of the outer phase capillary tube is 800 mu m; then connecting the inner phase capillary tube with the inner phase liquid inlet device to form an inner phase fluid circulation pipeline, connecting the intermediate phase capillary tube with the intermediate phase liquid inlet device to form an intermediate phase fluid circulation pipeline, and connecting the outer phase capillary tube with the outer phase liquid inlet device to form an outer phase fluid circulation pipeline;

s2, preparing an aqueous solution with an inner phase having both electrical conductivity and photo-thermal responsiveness, and introducing a mesophase contractive hydrogel solution and an outer phase curing solution into the microfluidic spinning device assembled in the step S1 respectively, wherein all fluids flow in the same direction;

and S3, adjusting the flow rate of each phase fluid, and finally curing to form the linear type core-shell structure conductive fiber.

The inner phase aqueous solution with conductivity and photo-thermal responsiveness is MXene aqueous solution, the intermediate phase contractive hydrogel solution is sodium alginate (Na-Alg) aqueous solution doped with N-isopropylacrylamide (NIPAM) hydrogel, and the outer phase solidified solution is calcium chloride (CaCl)₂) An aqueous solution.

In step S2, the mesophase shrinkage hydrogel solution and the aqueous solution with both electrical conductivity and photo-thermal responsiveness in the internal phase are sequentially and respectively introduced into the mesophase capillary and the internal phase capillary to obtain a core-shell fiber precursor in a laminar flow state, and then the core-shell fiber precursor is cured by introducing the external phase curing solution into the external phase capillary to maintain the core-shell structure of the conductive fiber; the core-shell ratio of the linear core-shell structure conductive fiber is adjusted by adjusting the flow rate of each phase fluid, wherein the flow rate adjusting range of each phase is as follows: the flow rate of the fluid in the inner phase is adjusted to be 0.1-0.5 mL/h, the flow rate of the fluid in the middle phase is 1.5-2.5 mL/h, the flow rate of the fluid in the outer phase is 8-16 mL/h, and the wall thickness of the linear core-shell structure conductive fiber is changed within the range of 100-300 microns, so that the regulation and control of the conductivity, the photo-thermal responsiveness and the shrinkage performance of the linear core-shell structure conductive fiber are realized.

The linear type core-shell structure conductive fiber is prepared by adopting the preparation method.

Further, the diameter of the linear type core-shell structure conductive fiber is 200-400 μm.

The linear type core-shell structure conductive fiber is applied to a photo-thermal response flexible electronic system, and the fiber temperature of the linear type core-shell structure conductive fiber is correspondingly changed under the irradiation of near infrared light to drive the fiber to contract so as to adjust the electrical property of the fiber.

Compared with the prior art, the invention has the beneficial effects that: the invention provides a microfluidic spinning device and a method for preparing a linear type core-shell structure conductive fiber by adopting the device, the microfluidic spinning device has simple channel, low cost and convenient assembly and operation, and the accurate regulation and control of the shape of the linear type core-shell structure conductive fiber can be realized by regulating the flow velocity of fluid of an internal phase, a middle phase and an external phase; the prepared linear type core-shell structure conductive fiber takes MXene aqueous solution as a core layer, the sheath layer is a contractive alginate hydrogel material with good biocompatibility and doped with NIPAM, the good core-shell structure is ensured, meanwhile, excellent conductive performance and photothermal contractive performance are endowed, the practicability is high, and the linear type core-shell structure conductive fiber can be applied to a series of flexible electronic products needing photothermal response.

Drawings

FIG. 1 is a schematic structural diagram of a capillary microfluidic spinning device according to the present invention;

fig. 2 is an example diagram of a linear core-shell structure conductive fiber according toembodiment 1 of the present invention;

FIG. 3 is a graph of the shape control of the linear core-shell structured conductive fiber according toembodiment 2 of the present invention;

FIG. 4 is a graph showing electrical property curves of the linear core-shell structure conductive fibers in example 3 of the present invention;

FIG. 5 is a physical diagram of the photothermal shrinkage performance of the linear core-shell structured conductive fiber in example 4 of the present invention;

FIG. 6 is a graph showing the photo-thermal response of the linear core-shell structure conductive fiber in light-temperature according to example 4 of the present invention;

fig. 7 is a photo-thermal response application diagram of the linear core-shell structure conductive fiber in the photo-electric aspect in example 4 of the present invention.

Wherein the reference numerals are: the device comprises an internal phase capillary 1, an intermediate phase capillary 2, anobservation capillary 3, an external phase capillary 4, an internal phaseliquid inlet device 5, an intermediate phaseliquid inlet device 6 and an external phaseliquid inlet device 7.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings.

The experimental procedures used in the examples below are, unless otherwise specified, conventional procedures and the reagents, methods and equipment used are, unless otherwise specified, conventional in the art.

As shown in figure 1, the microfluidic spinning device comprises an inner phasecapillary tube 1, an intermediate phasecapillary tube 2, an observationcapillary tube 3, an outer phasecapillary tube 4, an inner phaseliquid inlet device 5, an intermediate phaseliquid inlet device 6 and an outer phaseliquid inlet device 7, wherein the inner phasecapillary tube 1, the intermediate phasecapillary tube 2, the observationcapillary tube 3 and the outer phasecapillary tube 4 are all glass capillary tubes, the outflow port of the inner phasecapillary tube 1 is in a pointed cone shape, the inner diameter of the inner phasecapillary tube 1 is 1/3-1/2 of the inner diameter of the intermediate phasecapillary tube 2, the outflow port of the intermediate phasecapillary tube 2 is in a pointed cone shape, the intermediate phasecapillary tube 2 is coaxially sleeved at the rear part of the inner phasecapillary tube 1, the inner diameter of the intermediate phasecapillary tube 2 is 1/4-3/4 of the inner diameter of the outer phasecapillary tube 4, the outflow port of the outer phase capillary, theobservation capillary 3 is a square capillary and is positioned at the interface of theintermediate phase capillary 2 and the external phase capillary 4, the interfaces of the internal phase capillary 1, the intermediate phase capillary 2, the observation capillary 3 and the external phase capillary 4 are all sealed by transparent epoxy resin, the internal phase capillary 1 is connected with the internal phaseliquid inlet device 5 to form an internal phase fluid circulation pipeline, the intermediate phase capillary 2 is connected with the intermediate phaseliquid inlet device 6 to form an intermediate phase fluid circulation pipeline, and theexternal phase capillary 4 is connected with the external phaseliquid inlet device 7 to form an external phase fluid circulation pipeline.

The structure of the inner phaseliquid inlet device 5, the structure of the middle phaseliquid inlet device 6 and the structure of the outer phaseliquid inlet device 7 are the same, the inner phaseliquid inlet device 5, the structure of the middle phaseliquid inlet device 6 and the structure of the outer phaseliquid inlet device 7 are all composed of an injection pump and a syringe connecting needle, the injection pump is communicated with the syringe connecting needle through a guide pipe, the syringe connecting needles of the inner phaseliquid inlet device 5, the middle phaseliquid inlet device 6;

optimally, the inner diameter of the inner phasecapillary tube 1 is 100-200 μm; the inner diameter of the intermediate phase capillary 2 is 250-350 μm; the inner diameter of the outer phase capillary 4 was 800. mu.m.

Example 1

A linear type core-shell structure MXene conductive fiber comprises the following steps:

s1, assembling the microfluidic spinning device: referring to fig. 1, an internal phase capillary 1, an intermediate phase capillary 2 and an external phase capillary 4, which have inner diameters of 100 μm, 250 μm and 800 μm, respectively, are coaxially assembled into anobservation capillary 3, and are encapsulated with transparent epoxy resin at necessary positions (at a joint between the internal phase capillary 1 and theintermediate phase capillary 2, at a joint between theintermediate phase capillary 2 and the observation capillary 3, and at a joint between the external phase capillary 4 and the observation capillary 3); then connecting theinternal phase capillary 1 with an internal phaseliquid inlet device 5 to form an internal phase fluid circulation pipeline, connecting theintermediate phase capillary 2 with an intermediate phaseliquid inlet device 6 to form an intermediate phase fluid circulation pipeline, and connecting theexternal phase capillary 4 with an external phaseliquid inlet device 7 to form an external phase fluid circulation pipeline;

S2M in which the internal phase of the preparation had both electrical conductivity and photothermal responsiveness, and the aqueous solution was 5mg/mLThe Xenes aqueous solution and the mesophase shrinkage hydrogel solution are 10: 1, 1.5wt% aqueous Na-Alg solution: 10wt% NIPAM aqueous solution, external phase solidification collection solution is 2wt% CaCl₂An aqueous solution;

s3, respectively injecting an aqueous solution with both electric conductivity and photo-thermal responsiveness in an inner phase, a shrinkage hydrogel solution in an intermediate phase and a solidification and collection solution in an outer phase into theinner phase capillary 1, the intermediate phase capillary 2 and the outer phase capillary 4 through the inner phaseliquid inlet device 5, the intermediate phaseliquid inlet device 6 and the outer phaseliquid inlet device 7, adjusting the flow rate of an inner phase fluid to be 0.1-0.5 mL/h, the flow rate of an intermediate phase fluid to be 1.5-2.5 mL/h and the flow rate of an outer phase fluid to be 8-16 mL/h, and preparing the stable linear MXene conductive fiber with the core-shell structure;

as shown in fig. 2, linear core-shell structured MXene conductive fibers with different wall thicknesses are prepared by adjusting the flow rates of the internal phase fluid, the intermediate phase fluid and the external phase fluid only in this embodiment, where fig. 2a is a linear core-shell structured MXene conductive fiber prepared when the flow rate of the internal phase fluid, the flow rate of the intermediate phase fluid and the flow rate of the external phase fluid are 0.2mL/h, 2mL/h and 10mL/h, respectively; FIG. 2b shows linear MXene conductive fibers with core-shell structure prepared when the flow rates of the inner phase fluid, the intermediate phase fluid and the outer phase fluid are respectively 0.5mL/h, 1.5mL/h and 10 mL/h.

Example 2: morphology regulation and control of linear type core-shell structure conductive fiber

The microfluidic spinning device assembled in theembodiment 1 is adopted to prepare the linear type core-shell structure conductive fiber, and in the preparation process, the inner phase MXenes aqueous solution, the intermediate phase Na-Alg/NIPAM aqueous solution or the outer phase CaCl is adjusted₂The change of the wall thickness of the linear core-shell structure conductive fiber can be observed on line by the flow velocity of the aqueous solution, so as to realize the precise regulation and control of the appearance of the linear core-shell structure conductive fiber, as shown in fig. 3, wherein fig. 3a is external phase CaCl₂The flow velocity of the aqueous solution is fixed, and the wall thickness of the linear type core-shell structure conductive fiber changes when the flow velocities of the internal phase MXenes aqueous solution and the intermediate phase Na-Alg/NIPAM aqueous solution are adjusted; FIG. 3b shows the adjustment of the flow rate of the aqueous Na-Alg/NIPAM intermediate phase to adjust the internal MXenes aqueous solution and the external CaCl phase₂Flow rate of aqueous solution, straight lineThe wall thickness change condition of the core-shell structure conductive fiber; the wall thickness of the linear type core-shell structure conductive fiber can be changed between 100 and 300 mu m, and the subsequent accurate regulation and control of the conductivity and the shrinkage performance of the linear type core-shell structure conductive fiber are realized by regulating and controlling the appearance, such as the wall thickness, of the linear type core-shell structure conductive fiber, so that a foundation is laid for the subsequent flexible electronic application.

Example 3: electrical property test of linear type core-shell structure conductive fiber

Taking MXene as a core and hydrogel as a shell as shown in FIG. 2 in example 1, and taking a linear type core-shell structure conductive fiber prepared at different flow rates as an example, the resistance performance of the linear type core-shell structure conductive fiber under different lengths, different inner core sizes and different stretching conditions was tested, and a corresponding resistance change value was calculated, as shown in FIG. 4;

the linear type core-shell structure conductive fibers with different inner core sizes are obtained by adjusting the flow rate of an inner phase solution (adjusting the flow rate of the inner phase from 0.1 mL/h to 0.5mL/h, and keeping the flow rate of a middle phase and the flow rate of an outer phase to be 1.5mL/h and 10mL/h respectively) on the basis of the same microfluidic spinning device, and have the same length and different inner diameters. As shown in fig. 4a, it is a graph of the relationship between the resistance of the linear core-shell structure conductive fiber and the inner diameter thereof under the same test length condition; specifically, the larger the inner diameter of the linear core-shell structure conductive fiber is, the smaller the resistance of the fiber is, and the better the conductivity is;

the linear type core-shell structure conductive fibers with different lengths are prepared based on the same microfluidic spinning device, namely the inner diameters of the linear type core-shell structure conductive fibers are controlled to be consistent (the flow rates of an inner phase, a middle phase and an outer phase are controlled to be 0.3mL/h, 1.5mL/h and 10mL/h uniformly). As shown in fig. 4b, under the same inner diameter of the test fiber, the electrical resistance of the fiber is increased and the electrical conductivity is not outstanding by changing the test length of the fiber to be longer;

fig. 4c shows the resistance change of the linear core-shell structure conductive fiber with a specific length (2 cm) and a specific inner diameter (corresponding to a flow rate of the internal phase/intermediate phase/external phase fluid of 0.3 mL/h/1.5 mL/h/10 mL/h) under different stretching conditions, and it can be seen that the greater the stretching degree, the less outstanding the conductivity of the fiber;

fig. 4d shows the resistance change of the linear core-shell structure conductive fiber wrapped in the elastic film and having the same length and inner diameter as those of fig. 4c under different stretching conditions, wherein the change trend is similar to that of the unencapsulated single fiber, but the stretching degree is increased.

The results prove that the linear type core-shell structure conductive fiber prepared by the method has stable and excellent electrical properties and can play a great application potential in flexible electronic systems such as flexible skins.

Example 4: photo-thermal response application of linear type core-shell structure conductive fiber

Referring to example 1, taking MXene as a core and linear conductive fibers (prepared according to the flow rates of 0.5mL/h of internal phase fluid, 2mL/h of intermediate phase flow rate and 8 mL/h of external phase fluid) with shrinkable hydrogel as a shell as an example, the linear conductive fibers with the core-shell structure are irradiated under near infrared light, the shrinkage condition and the temperature change of the fibers are observed, the resistance change condition of the fibers is simultaneously observed in real time, the repeatability of photothermal-shrinkage-resistance response is researched, the value of the fibers in practical application is explored, and the result is shown in FIGS. 5 to 7.

As shown in fig. 5, it is a physical diagram of the photo-thermal shrinkage performance of the linear core-shell structure conductive fiber;

as shown in fig. 6a, the temperature of the fiber surface was increased faster as the irradiation power was higher, as a result of examining the irradiation power and the fiber surface temperature while maintaining the irradiation distance under the irradiation of infrared light for 1 minute; FIG. 6b shows the results of a study of the irradiation distance and the fiber surface temperature under 1 minute infrared irradiation with the irradiation power kept constant, and shows that the temperature of the fiber surface increases faster the closer the irradiation distance; fig. 6c shows that the recovery condition of the linear core-shell structure conductive fiber after 30s infrared irradiation is observed while the irradiation power and the irradiation distance are kept unchanged, and 20 times of cycle tests are performed, so that the linear core-shell structure conductive fiber is finally proved to have excellent heat recovery performance;

as shown in fig. 7a, the results of examining the change in the fiber resistance and the irradiation power with the irradiation distance kept constant under 1 minute infrared irradiation revealed that the higher the irradiation power, the faster the fiber resistance decreased; FIG. 7b shows the results of examining the change in the fiber resistance and the irradiation distance with the irradiation power kept constant for 1 minute of infrared irradiation, and it was found that the resistance of the fiber decreased more rapidly the closer the irradiation distance; FIG. 7c is a graph showing the recovery of the fiber resistance after 30s infrared irradiation, with the irradiation power and irradiation distance kept unchanged, and with 20 cycles of tests, the resistance recovery performance of the fiber is finally proved to be excellent; finally, the fact that the linear type core-shell structure conductive fiber can realize repeatable and stable resistance relative change in photo-thermal response can be proved, and a foundation is laid for specific application of flexible electronics.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.

Claims (10)

Translated fromChinese

1.一种微流控纺丝装置，其特征在于，包括内相毛细管（1）、中间相毛细管（2）、观察毛细管（3）、外相毛细管（4）、内相进液装置（5）、中间相进液装置（6）和外相进液装置（7），所述中间相毛细管（2）同轴套接于内相毛细管（1）后部，所述外相毛细管（4）同轴套接于中间相毛细管（2）后部，所述观察毛细管（3）位于中间相毛细管（2）和外相毛细管（4）接口处，所述内相毛细管（1）与内相进液装置（5）相连，形成内相流体流通管道，所述中间相毛细管（2）与中间相进液装置（6）相连，形成中间相流体流通管道，所述外相毛细管（4）与外相进液装置（7）相连，形成外相流体流通管道。1. A microfluidic spinning device, characterized in that it comprises an inner phase capillary (1), an intermediate phase capillary (2), an observation capillary (3), an outer phase capillary (4), and an inner phase liquid inlet device (5) , an intermediate phase liquid inlet device (6) and an external phase liquid inlet device (7), the intermediate phase capillary (2) is coaxially sleeved at the rear of the inner phase capillary (1), and the outer phase capillary (4) is coaxially sleeved Connected to the rear of the mesophase capillary (2), the observation capillary (3) is located at the interface of the mesophase capillary (2) and the outer phase capillary (4), and the inner phase capillary (1) is connected to the inner phase liquid inlet device (5). ) are connected to form an inner phase fluid circulation pipeline, the mesophase capillary (2) is connected with the intermediate phase liquid inlet device (6) to form an intermediate phase fluid circulation pipeline, and the outer phase capillary tube (4) is connected to the outer phase liquid inlet device (7) ) are connected to form an external phase fluid circulation pipeline.2.根据权利要求1所述的微流控纺丝装置，其特征在于：所述内相进液装置（5）、中间相进液装置（6）和外相进液装置（7）结构相同，均包括注射泵和注射器连接针头，注射泵通过导管与注射器连接针头接通，所述内相进液装置（5）、中间相进液装置（6）和外相进液装置（7）的注射器连接针头通过导管分别与内相毛细管（1）、中间相进液装置（6）和外相进液装置（7）连通，内相流体、中间相流体和外相流体的流向相同。2 . The microfluidic spinning device according to claim 1 , wherein the inner phase liquid feeding device ( 5 ), the intermediate phase liquid feeding device ( 6 ) and the outer phase liquid feeding device ( 7 ) have the same structure, 2 . All include a syringe pump and a syringe connecting needle, the syringe pump is connected to the syringe connecting needle through a catheter, and the syringes of the inner phase liquid feeding device (5), the intermediate phase liquid feeding device (6) and the external phase liquid feeding device (7) are connected The needle is respectively communicated with the inner phase capillary (1), the intermediate phase liquid inlet device (6) and the outer phase liquid inlet device (7) through the conduit, and the flow directions of the inner phase fluid, the intermediate phase fluid and the outer phase fluid are the same.3.根据权利要求2所述的微流控纺丝装置，其特征在于：所述内相毛细管（1）、中间相毛细管（2）、观察毛细管（3）和外相毛细管（4）均为玻璃毛细管，且内相毛细管（1）内径为中间相毛细管（2）内径的1/3～1/2，中间相毛细管（2）内径为外相毛细管（4）内径的1/4～3/4，内相毛细管（1）、中间相毛细管（2）、观察毛细管（3）和外相毛细管（4）的各接口处均用透明环氧树脂进行密封。3. The microfluidic spinning device according to claim 2, wherein the inner phase capillary (1), the intermediate phase capillary (2), the observation capillary (3) and the outer phase capillary (4) are all glass capillary, and the inner diameter of the inner phase capillary (1) is 1/3 to 1/2 of the inner diameter of the intermediate phase capillary (2), and the inner diameter of the intermediate phase capillary (2) is 1/4 to 3/4 of the inner diameter of the outer phase capillary (4), Each interface of the inner phase capillary (1), the intermediate phase capillary (2), the observation capillary (3) and the outer phase capillary (4) is sealed with transparent epoxy resin.4.根据权利要求3所述的微流控纺丝装置，其特征在于：所述内相毛细管（1）流出端口为尖锥形，内相毛细管（1）的内径为100～200μm；中间相毛细管（2）的流出端口为尖锥形，中间相毛细管（2）的内径为250～350μm；外相毛细管（4）的流出端口为圆形，外相毛细管（4）的内径为800μm；观察毛细管（3）为方形毛细管。4 . The microfluidic spinning device according to claim 3 , wherein the outflow port of the inner phase capillary ( 1 ) is tapered, and the inner diameter of the inner phase capillary ( 1 ) is 100-200 μm; The outflow port of the capillary (2) is a pointed cone, the inner diameter of the intermediate phase capillary (2) is 250-350 μm; the outflow port of the outer phase capillary (4) is circular, and the inner diameter of the outer phase capillary (4) is 800 μm; the observation capillary ( 3) is a square capillary.5.一种直线型核壳结构导电纤维的制备方法，其特征在于，采用权利要求1～4任一项所述的微流控纺丝装置制备，包括以下步骤：5. A method for preparing a linear core-shell structure conductive fiber, characterized in that, using the microfluidic spinning device according to any one of claims 1 to 4 to prepare, comprising the following steps:S1、组装微流控纺丝装置：将内相毛细管（1）同轴组装到中间相毛细管（2）中，中间相毛细管（2）同轴组装到外相毛细管（4）中，观察毛细管（3）套接于中间相毛细管（2）和外相毛细管（4）接口处，其中内相毛细管（1）的内径为100～200μm，中间相毛细管（2）的内径为250～350μm，外相毛细管（4）的内径为800μm；然后将内相毛细管（1）与内相进液装置（5）相连，形成内相流体流通管道，所述中间相毛细管（2）与中间相进液装置（6）相连，形成中间相流体流通管道，所述外相毛细管（4）与外相进液装置（7）相连，形成外相流体流通管道；S1. Assemble the microfluidic spinning device: Assemble the inner phase capillary (1) coaxially into the mesophase capillary (2), and coaxially assemble the mesophase capillary (2) into the outer phase capillary (4), observe the capillary (3) ) is sleeved at the interface of the mesophase capillary (2) and the outer phase capillary (4), wherein the inner diameter of the inner phase capillary (1) is 100-200 μm, the inner diameter of the mesophase capillary (2) is 250-350 μm, and the outer phase capillary (4 ) with an inner diameter of 800 μm; then the inner phase capillary (1) is connected to the inner phase liquid inlet device (5) to form an inner phase fluid circulation pipeline, and the intermediate phase capillary (2) is connected to the intermediate phase liquid inlet device (6) , forming an intermediate-phase fluid circulation pipeline, and the outer-phase capillary (4) is connected with the outer-phase liquid inlet device (7) to form an outer-phase fluid circulation pipeline;S2、配制内相兼具导电性和光热响应性水溶液，中间相收缩性水凝胶溶液和外相固化溶液，分别导入到步骤S1组装的微流控纺丝装置中，所有流体同向流动；S2. Prepare an aqueous solution with both electrical conductivity and photothermal response in the inner phase, a shrinkable hydrogel solution in the mesophase and a solidification solution in the outer phase, which are respectively introduced into the microfluidic spinning device assembled in step S1, and all fluids flow in the same direction;S3、调整各相流体的流速，最终固化后形成直线型核壳结构导电纤维。S3, adjusting the flow rate of each phase fluid, and finally forming a linear core-shell structure conductive fiber after solidification.6.根据权利要求5所述的直线型核壳结构导电纤维的制备方法，其特征在于：所述内相兼具导电性和光热响应性水溶液选用MXene水溶液，所述中间相收缩性水凝胶溶液选用掺有N-异丙基丙烯酰胺水凝胶的海藻酸钠水溶液，所述外相固化溶液选用氯化钙水溶液。6 . The method for preparing a linear core-shell structure conductive fiber according to claim 5 , wherein the inner phase has both electrical conductivity and photothermal responsiveness and an aqueous solution of MXene is selected as the aqueous solution, and the mesophase shrinkage hydraulic The glue solution is selected from sodium alginate aqueous solution mixed with N-isopropylacrylamide hydrogel, and the external phase solidified solution is selected from calcium chloride aqueous solution.7.根据权利要求5所述的直线型核壳结构导电纤维的制备方法，其特征在于：步骤S2中，所述中间相收缩性水凝胶溶液和内相兼具导电性和光热响应性水溶液按先后顺序分别导入中间相毛细管（2）和内相毛细管（1）中，得到呈层流状态的核壳结构纤维前体，再通过将外相固化溶液导入外相毛细管（4）中，以固化核壳结构纤维前体，从而保持导电纤维的核壳结构；通过调节各相流体流速，以实现对直线型核壳结构导电纤维的核壳比调节，其中，各相流速调节范围为：调节内相流体流速为0.1～0.5mL/h，中间相流体流速为1.5～2.5mL/h，外相流体流速为8～16mL/h，直线型核壳结构导电纤维的壁厚在100～300μm区间内改变，进而实现对直线型核壳结构导电纤维的导电性、光热响应性、收缩性能的调控。7 . The method for preparing a linear core-shell conductive fiber according to claim 5 , wherein in step S2 , the mesophase shrinkable hydrogel solution and the inner phase have both electrical conductivity and photothermal responsiveness. 8 . The aqueous solution is respectively introduced into the intermediate phase capillary (2) and the inner phase capillary (1) in sequence to obtain a core-shell structure fiber precursor in a laminar flow state, and then the outer phase solidification solution is introduced into the outer phase capillary (4) to solidify The core-shell structure fiber precursor is used to maintain the core-shell structure of the conductive fiber; by adjusting the fluid flow rate of each phase, the core-shell ratio adjustment of the linear core-shell structure conductive fiber is realized, wherein the adjustment range of the flow rate of each phase is: The flow rate of the phase fluid is 0.1-0.5mL/h, the flow rate of the intermediate phase fluid is 1.5-2.5mL/h, and the flow rate of the outer-phase fluid is 8-16mL/h. , and then realize the regulation of the electrical conductivity, photothermal responsiveness and shrinkage performance of the linear core-shell conductive fibers.8.一种直线型核壳结构导电纤维，其特征在于，采用权利要求5～7任一项所述的制备方法制得。8 . A linear core-shell structure conductive fiber, characterized in that, it is prepared by the preparation method according to any one of claims 5 to 7 .9.根据权利要求8所述的直线型核壳结构导电纤维，其特征在于：所述直线型核壳结构导电纤维的直径为200～400μm。9 . The linear core-shell structure conductive fiber according to claim 8 , wherein the diameter of the linear core-shell structure conductive fiber is 200-400 μm. 10 .10.权利要求8或9所述的直线型核壳结构导电纤维在光热响应性柔性电子系统中的应用，其特征在于，所述直线型核壳结构导电纤维在近红外光照射下纤维温度发生相应变化，带动纤维收缩以调节其电学性能。10. The application of the linear core-shell structure conductive fiber according to claim 8 or 9 in a photothermal responsive flexible electronic system, wherein the linear core-shell structure conductive fiber has a fiber temperature under near-infrared light irradiation. Corresponding changes occur, driving the fibers to shrink to adjust their electrical properties.

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