CN112525226A

CN112525226A - Additive manufacturing equipment and method for sensing elastic foam and multi-channel coaxial extrusion of sensing elastic foam

Info

Publication number: CN112525226A
Application number: CN202011485385.7A
Authority: CN
Inventors: 刘禹; 徐嘉文; 张星浩; 张阳; 姜晶
Original assignee: Jiangnan University
Current assignee: Jiangnan University
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2021-03-19
Also published as: WO2022126943A1

Abstract

The invention relates to the field of flexible electronic technology and additive manufacturing, in particular to a sensing elastic foam and an additive manufacturing device and method for multi-channel coaxial extrusion thereof. The sensing elastic foam of the present invention is an elastic dielectric unit, which is formed by stacking no less than 3 layers of porous grids, and each layer of porous grids is formed by interweaving core-shell linear structural units, and the core-shell linear structural units include An elastic line unit, a sensing unit and a wire unit, wherein the sensing unit and the wire unit are cores, and the elastic line unit is a shell. The invention adopts the multi-channel coaxial extrusion additive manufacturing equipment to prepare the sensing elastic foam, and achieves the purpose of switching printing different line patterns by adjusting the printing parameters online, thereby completing the continuous manufacture of different functional units of the sensing elastic foam.

Description

Additive manufacturing equipment and method for sensing elastic foam and multi-channel coaxial extrusion of sensing elastic foam

Technical Field

The invention relates to the field of flexible electronic technology and additive manufacturing, in particular to additive manufacturing equipment and method for sensing elastic foam and multi-channel coaxial extrusion of the elastic foam.

Background

With the continuous progress of scientific technology, more and more electronic products are turned to flexibility and personalized customization, such as wearable devices, flexible circuit antennas, microwave cables, electronic skins and the like, and these electronic products not only require the normal operation of electronic components, but also require that the electronic components can be elastically deformed according to the needs of users, and thus flexible sensors therein are required, and have both sensing function and elastic deformation, and such needs undoubtedly create great challenges for the traditional manufacturing. The related research and manufacture of the existing flexible sensor is to embed a conductive material into an elastic material by means of a mold and perform encapsulation molding. However, the related research and manufacture of the existing flexible sensor has the following limitations: (1) the existing flexible sensor is manufactured by adopting a traditional casting mould mode, a mould needs to be manufactured in advance, the production cost is very high, and if different process adjustment is carried out according to different requirements, the mould needs to be replaced according to the requirements, so that a great deal of waste of manpower, time and cost is caused; (2) due to the factors, the existing flexible sensor is difficult to meet more and more personalized customization requirements of users.

Disclosure of Invention

In view of the above problems in the prior art, the present invention provides an additive manufacturing apparatus and method for sensing elastic foam and multi-channel coaxial extrusion thereof. The multi-channel coaxial extrusion additive manufacturing equipment and method for the sensing elastic foam overcome the problems of the traditional mask and layered manufacturing mode, have the advantages of high forming speed, wide applicable materials, uninterrupted process, high customization degree and the like, and integrally save labor, time and production cost.

In order to solve the defects of the prior art, the invention adopts the following technical scheme: the sensing elastic foam is an elastic dielectric unit and is formed by stacking at least 3 layers of porous grids, each layer of porous grids is formed by interweaving core-shell line structure units, each core-shell line structure unit comprises an elastic line unit, a sensing unit and a lead unit, the sensing unit and the lead unit are cores, and the elastic line unit is a shell.

Further, the line width of the elastic line unit is 500-; the line width of the sensing unit is 10-1500 microns, and the line width of the wire unit is 10-1500 microns.

Further, the pattern type of the porous grid is one of a criss-cross type, a triangular shape or a hexagonal shape.

The utility model provides a vibration material disk equipment that multichannel was coaxially extruded, includes air compressor machine, gas circuit branch line head, electron pneumatic valve, connects the trachea, loads feed cylinder, the coaxial shower nozzle of multichannel, XYZ motion module, anchor clamps and fuselage, be provided with XYZ motion module on the fuselage, load the feed cylinder and pass through anchor clamps and fix on the fuselage, the air compressor machine passes through gas circuit branch line head and connects the trachea and load feed cylinder and multichannel coaxial shower nozzle is connected, be provided with electron pneumatic valve between gas circuit branch line head and the loading feed cylinder for the extrusion of different mode lines of control, the coaxial shower nozzle of multichannel is located Y motion module directly over.

Furthermore, the multi-channel coaxial nozzle comprises a first channel, a second channel and a third channel, the three channels are arranged in the coaxial nozzle, are not communicated with each other and converge at the tail end of the nozzle to form a height difference, the third channel envelopes the second channel, the second channel envelopes the first channel, and the overall size of the nozzle is 0.6-1.5 mm.

Further, the loading barrel comprises a sensing material barrel, a wire material barrel and an elastic material barrel, wherein the sensing material barrel is connected with the first channel, and sensing material is extruded from the first channel;

the wire material barrel is connected with the second channel, and the wire material is extruded from the second channel;

the elastomeric cartridge is connected to the third passageway and elastomeric material is extruded from the third passageway.

Further, the sensing material comprises carbon-based conductive liquid, carbon-based conductive paste, conductive polymer hydrogel and conductive ion gelOne or more of the glues, the sensing material having a conductivity of 10²~10⁵S/m, viscosity of 10²~10⁶cps；

The wire material comprises one or more of conductive ionic liquid, conductive polymer solution and gallium indium tin alloy, and has a conductivity of 10⁵~10⁷S/m, viscosity of 1 to 10³cps；

The elastic material comprises one or more of polydimethylsiloxane, polyurethane, thermoplastic rubber and thermoplastic resin, and has a suitable viscosity of 10⁵~10⁹cps。

Further, the multi-channel coaxial extrusion additive manufacturing equipment performs line mode conversion and adjustment methods, and the line mode conversion and adjustment methods mainly realize extrusion of lines in different modes by switching on and off of air pressure switches of respective channels:

opening a third channel, opening a first channel, closing a second channel, and extruding to form a sensing unit;

opening a third channel, closing the first channel, opening the second channel, and extruding to form a lead unit;

opening a third channel, closing the first channel and closing the second channel, and extruding to form an elastic line unit;

the air pressure range of each channel is 0-800 KPa, and the proportion of the line width occupied by the sensing material is adjusted by changing the air pressure proportion of each channel.

The preparation method of the sensing elastic foam comprises the following steps:

a. installing the multi-channel coaxial nozzle on a clamp at the tail end of the Z-shaped moving module;

b. elastic materials, lead materials and sensing materials are correspondingly loaded in the loading charging barrel and are connected with the electronic pneumatic valve and the air compressor through the connecting air pipe and the branch line head;

c. generating a printing path through a control system, setting the printing speed of continuous additive manufacturing equipment to be 0.1-50 mm/s, setting extrusion parameters of three line modes,

elastic unit: setting the air pressure of the first channel to be 0 kPa, the air pressure of the second channel to be 0 kPa, and the air pressure of the third channel to be 600-800 kPa;

the sensing unit: setting the air pressure of the first channel to be 0 kPa, the air pressure of the second channel to be 350-400 kPa and the air pressure of the third channel to be 600-800 kPa;

wire unit: setting the air pressure of the first channel to be 300-500 kPa, the air pressure of the second channel to be 0 kPa and the air pressure of the third channel to be 600-900 kPa;

d. adjusting the multi-channel coaxial nozzle to a position 0.1-0.9 mm above the plane where the Y-shaped movement module is located, wherein the adjustment height is 0.9 times of the inner diameter of the multi-channel coaxial nozzle;

e. the motion control technology and the extrusion system control work cooperatively, a printing path and a corresponding line mode are set, self-supporting is completed by utilizing the characteristic of high storage modulus of a shell layer elastic material, and meanwhile, a lead material or/and a sensing material are/is extruded inside;

f. after the grid structure is printed out, the grid structure is placed in a high-temperature environment with the temperature higher than 80 ℃ to be completely cured, nodes are connected when the grid structure is not cured, good cross-linking can be formed after curing, and internal materials are constrained in the inner layer of the wire body to form a coaxial elastic wire body structure, so that an elastic foam grid is constructed;

g. and f, inserting an external copper wire on the elastic foam grid obtained in the step f to be in contact with a wire material to serve as a lead-out wire, and packaging and forming by using photocuring silica gel to obtain the elastic capacitance sensing grid structure.

Further, an auxiliary curing apparatus including a heat curing heating plate and a heating light source is selectively configured for curing cases of different materials.

Compared with the prior art, the invention has the following advantages:

the invention avoids the traditional complex production process of utilizing a die or manually, can meet the requirements of different users on any plane topological structure, geometric dimension and the like, simultaneously has the advantages of good forming, high continuity, uninterrupted process and the like, and saves labor, time and production cost.

The invention adopts liquid or colloid material, and the foam produced by the liquid or colloid material has elasticity due to the good elastic deformation of the liquid or the colloid. When the elastic material is silicon rubber, the prepared elastic foam has obvious advantages because the silicon rubber has good insulativity and elastic deformation capability, is nontoxic and tasteless, resists high temperature and low temperature, and has good inertia.

The invention can continuously switch and print lines with different functional modes, so that the elastic foam structure with the force sensing function can be formed by one-time continuous printing, has the advantages of high integration, high forming speed and the like, and can solve the problem that the sensing unit is led out from a lead inside the elastic foam body.

The method can realize arbitrariness and adjustability through software programming according to requirements; and regulating and controlling printing parameters, namely the distance between the coaxial spray head and the printing substrate, the specification of the coaxial spray head, a preset path and the extrusion air pressure of the extrusion system, so as to realize the adjustment of the wire material and the content of the sensing material in the coaxial lines in the elastic foam, the thickness of the line elastic material and the switching of the line mode.

The multi-channel coaxial nozzle can finish the deposition of lines in different modes in the process of one-time printing, compared with the mode of multi-nozzle switching, the multi-material deposition is finished, the steps of nozzle switching and positioning for head-to-tail printing are omitted, the continuously printed lines have the advantages of being higher in interface performance and higher in printing speed, materials without self-supporting can be used in the inner core materials, and the usable material system is expanded.

Drawings

FIG. 1 is a schematic view showing the structure of a sensor elastic foam in embodiment 1 of the present invention.

FIG. 2 is a schematic structural view of a single coaxial line element in the sensor resilient foam of FIG. 1.

Fig. 3 is a schematic structural diagram of a multi-channel additive manufacturing apparatus of the present invention.

Fig. 4 is a schematic structural view of the multi-channel coaxial showerhead of the present invention.

Fig. 5 is a schematic diagram of a path planning process of sensing elastic foam printing in embodiment 1 of the present invention.

Fig. 6 is a schematic diagram of a path planning process of sensing elastic foam printing in embodiment 2 of the present invention.

Description of reference numerals: 1-an air compressor; 2-gas path branching head; 3-an electronic pneumatic valve; 4-connecting the air pipe; 5-loading the material cylinder; 6-multi-channel coaxial nozzles; 7-XYZ motion module; 8-a clamp; 9-a fuselage; 10-sensing a resilient foam; 101-elastic line unit; 102-a sensing unit; 103-wire unit; 51-a sensing material cartridge; 52-a wire barrel; 53-a cylinder of elastomeric material; 61-a first channel; 62-a second channel; 63-a third channel; 71-X motion module; a 72-Y motion module; 73-Z motion module.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and examples. It should be understood that the scope of the above-described subject matter is not limited to the following examples, and any techniques implemented based on the disclosure of the present invention are within the scope of the present invention.

Example 1

As shown in fig. 1 and 2, a sensing elastic foam, where the sensing elastic foam 10 is an elastic dielectric unit formed by stacking at least 3 layers of porous grids, each layer of porous grids is formed by interweaving core-shell line structure units, each core-shell line structure unit includes an elastic line unit 101, a sensing unit 102, and a wire unit 103, where the sensing unit 102 and the wire unit 103 are cores, the elastic line unit 101 is a shell, the sensing unit 102 has a resistance, a capacitance, or an inductance that changes significantly after being deformed by a force, heated, or stimulated by other external factors, and the resistance and the change of the wire unit 103 are smaller than those of the sensing unit 102, so that the elastic foam can implement a sensing function.

The line width of the elastic line unit 101 is 1100 microns, and the wall thickness is 1100 microns; the line width of the sensing unit 102 is 1100 microns, the wall thickness is 300 microns, the inner core diameter is 500 microns, the line width of the wire unit 103 is 1100 microns, the wall thickness is 400 microns, and the inner core diameter is 300 microns.

As shown in fig. 3, a material increase manufacturing equipment that multichannel was coaxially extruded, including air compressor machine 1, gas circuit branch line head 2, electron pneumatic valve 3, connecting gas pipe 4, loading feed cylinder 5, multichannel coaxial shower nozzle 6, XYZ motion module 7, anchor clamps 8 and fuselage 9, be provided with XYZ motion module 7 on the fuselage 9, loading feed cylinder 5 passes through anchor clamps 8 to be fixed on fuselage 9, and air compressor machine 1 is connected with loading feed cylinder 5 and multichannel coaxial shower nozzle 6 through gas circuit branch line head 2 and connecting gas pipe 4, be provided with electron pneumatic valve 3 between gas circuit branch line head 2 and the loading feed cylinder 5 for control the extrusion of different mode lines, multichannel coaxial shower nozzle 6 is located Y motion module 71 directly over.

As shown in fig. 4, the multi-channel coaxial nozzle 6 includes a first channel 61, a second channel 62 and a third channel 63, the three channels are in the coaxial nozzle, are not communicated with each other, and converge at the nozzle end to form a height difference, wherein the third channel 3 envelopes the second channel 2, the second channel 2 envelopes the first channel 1, and the nozzle end size is 1.1 mm.

The loading barrel 5 comprises a sensing material barrel 51, a lead material barrel 52 and an elastic material barrel 53, wherein the sensing material barrel 51 is connected with a first channel 61, and sensing material is extruded from the first channel 61;

the wire material barrel 52 is connected with the second channel 62, and the wire material is extruded from the second channel 62;

the elastic material cylinder 53 is connected to the third passage 63, and the elastic material is extruded from the third passage 3.

The sensing material is conductive carbon paste with the conductivity of 4 x 10⁴S/m, viscosity of 10⁶cps；

The conducting wire material is a conducting polymer solution with the conductivity of 10⁵S/m, viscosity of 10³cps；

The elastic material is polydimethylsiloxane with the viscosity of 5 x 10⁶cps。

The preparation method of the sensing elastic foam is characterized in that three pressure sensing line units at different positions are embedded in the middle layer, and comprises the following steps:

a. conductive carbon paste is filled in a sensing material cylinder 51 connected with a first channel 61, a conductive polymer solution is filled in a lead material cylinder 52 connected with a second channel 62, and polydimethylsiloxane silicone rubber is filled in an elastic material cylinder 53 connected with a third channel 63;

b. the loading material cylinder 5 and the branch line head 2 are connected with the electronic pneumatic valve 3 and the air compressor 1 through the connecting air pipe 4; the inner diameter and the outer diameter of the tail end of each channel of the spray head are different, wherein the inner diameter of the tail end of the first channel 61 is 0.21 mm, and the outer diameter is 0.4 mm; the inner diameter of the end of the second channel 62 is 0.3 mm, and the outer diameter is 0.45 mm; the inner diameter of the end of the third channel 63 is 0.5 mm, and the outer diameter is 0.6 mm; the three spray heads are arranged in a wedge shape.

c. Generating a printing path through a control system, setting the printing speed of the continuous additive manufacturing equipment to be 15 mm/s, and setting extrusion parameters of three line modes:

elastic unit: setting the air pressure of the first channel 61 to be 0 kPa, the air pressure of the second channel 62 to be 0 kPa, and the air pressure of the third channel 63 to be 700 kPa;

the sensing unit: setting the air pressure of the first channel 61 to 0 kPa, the air pressure of the second channel 62 to 375 kPa, and the air pressure of the third channel 63 to 650 kPa;

wire unit: setting the air pressure of the first channel 61 to be 500 kPa, the air pressure of the second channel 62 to be 0 kPa, and the air pressure of the third channel 63 to be 700 kPa;

the multi-channel coaxial nozzle 6 is adjusted to be 0.9 mm above the plane where the Y-shaped movement module 71 is located;

initially, printing is carried out by using the corresponding air pressure of the elastic unit, when the elastic unit is deposited at a position where lines of the pressure sensing unit need to be placed in the middle layer, printing is carried out by using the corresponding air pressure of the sensing unit, after the sensing unit with a specified length is finished, printing is carried out by using the corresponding air pressure of the wire unit, the printing path is shown in fig. 5, and the elastic unit and the wire unit can be stacked layer by layer to form a grid shape;

d. placing the finished sample into an oven, maintaining the temperature of 80 ℃ for curing for 3 hours, and curing and forming the sensory elastic foam obtained in the step c to obtain the sensory elastic foam with the size of 30 x 10 mm, wherein the width of each coaxial line is about 0.7 mm.

e. And d, inserting copper wires with the diameter of 0.1 mm (the length of the copper wires which are immersed into the coaxial lines is 3-5 mm) into the two ends of each coaxial line of the sensing elastic foam obtained in the step d, injecting UV (ultraviolet) light curing glue into the two ends of the coaxial lines, then carrying out light curing, and leading out a test lead.

And (3) selectively configuring auxiliary curing equipment comprising a thermosetting heating plate and a heating light source according to curing conditions of different materials, and heating and curing the cladding material in the printing process to obtain a better cladding effect.

Finally, a sensor elastic foam as shown in FIG. 1 was produced, and the resistance of the sensor material embedded in the elastic foam was measured using a Keysight LCR meter, which was about 1.5 x 10⁶Omega, resistance 6 x 10 after compression of the foam⁸Ω。

Example 2

A sensing elastic foam is characterized in that the sensing elastic foam 10 is an elastic dielectric unit and is formed by stacking at least 3 layers of porous grids, each layer of porous grid is formed by interweaving a core-shell line structure unit, the core-shell line structure unit comprises an elastic line unit 101, a sensing unit 102 and a lead unit 103, the sensing unit 102 and the lead unit 103 are cores, the elastic line unit 101 is a shell, resistance, capacitance or inductance of the sensing unit 102 changes obviously after being deformed by stress, heated or stimulated by other external factors, and resistance and change of the lead unit 103 are smaller than those of the sensing unit 102, so that the sensing function of the elastic foam can be realized.

The line width of the elastic line unit 101 is 1200 micrometers, and the wall thickness is 1200 micrometers; the line width of the sensing unit 102 is 1200 microns, the wall thickness is 300 microns, the inner core diameter is 600 microns, the line width of the wire unit 103 is 1200 microns, the wall thickness is 450 microns, and the inner core diameter is 300 microns.

As shown in fig. 4, the multi-channel coaxial nozzle 6 includes a first channel 61, a second channel 62 and a third channel 63, the three channels are in the coaxial nozzle, are not communicated with each other, and converge at the end of the nozzle to form a height difference, wherein the third channel 3 envelopes the second channel 2, the second channel 2 envelopes the first channel 1, and the overall size of the nozzle is 1.1 mm.

The sensing material comprises graphene silica gel with the conductivity of 2 x 10³S/m, viscosity 4 x 10⁵cps；

The wire material comprises ionic conductive liquid with the conductivity of 3.3 x 10⁴S/m, viscosity of 10³cps；

The elastic material is thermosetting polyurethane with the viscosity of 2 x 10⁸cps。

The preparation method of the sensing elastic foam is characterized in that three temperature sensing line units at different positions are embedded in the middle layer, and comprises the following steps:

a. a temperature sensing material graphene silica gel is filled in a sensing material cylinder 51 connected with the first channel 61, liquid gallium indium tin alloy is filled in a lead material cylinder 52 connected with the second channel 62, and polyurethane is filled in an elastic material cylinder 53 connected with the third channel 63;

b. the loading material cylinder 5 and the branch line head 2 are connected with the electronic pneumatic valve 3 and the air compressor 1 through the connecting air pipe 4; the inner diameter and the outer diameter of the tail end of each channel of the spray head are different, wherein the inner diameter of the tail end of the first channel 61 is 0.4 mm, and the outer diameter is 0.6 mm; the inner diameter of the tail end of the second channel 62 is 0.6 mm, and the outer diameter is 0.7 mm; the inner diameter of the tail end of the third channel 63 is 0.7 mm, and the outer diameter is 1 mm;

c. generating a printing path through a control system, setting the printing speed of the additive manufacturing equipment to be 50 mm/s, and setting extrusion parameters of three line modes:

elastic unit: setting the air pressure of the first channel 61 to be 0 kPa, the air pressure of the second channel 62 to be 0 kPa, and the air pressure of the third channel 63 to be 800 kPa;

the sensing unit: setting the air pressure of the first channel 61 to be 0 kPa, the air pressure of the second channel 62 to be 400 kPa and the air pressure of the third channel 63 to be 800 kPa;

wire unit: setting the air pressure of the first channel 61 to be 500 kPa, the air pressure of the second channel 62 to be 0 kPa and the air pressure of the third channel 63 to be 800 kPa;

the multi-channel coaxial nozzle 6 is adjusted to be 0.45 mm above the plane where the Y-shaped movement module 71 is located, and the adjustment height is 0.9 times of the inner diameter of the multi-channel coaxial nozzle 6;

initially, printing is carried out by using the corresponding air pressure of the elastic unit, when the elastic unit is deposited at a position where a temperature sensing unit line needs to be placed in the middle layer, printing is carried out by using the corresponding air pressure of the sensing unit, after the sensing unit with a specified length is finished, printing is carried out by using the corresponding air pressure of the wire unit, the printing path is as shown in fig. 6, and the elastic unit and the wire unit can be stacked layer by layer to form a grid shape;

d. and (c) placing the finished sample into an oven, keeping the temperature of 80 ℃ for curing for 3 hours, and curing and forming the sensing elastic foam obtained in the step c to obtain the elastic foam with temperature sensing, wherein the width of each coaxial line is about 1.2 mm.

Finally, temperature sensing elastic foam is prepared, an LCR (liquid crystal storage controller) table of Keysight company is utilized to measure the resistance of the graphene silica gel embedded in the elastic foam, and the value of the resistance is about 3 x 10 at the normal temperature of 25 DEG C⁶Omega, resistance of 3.42 x 10 at around 0 ℃ ambient temperature⁶Ω。

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modification, change and equivalent changes of the above embodiments according to the principles of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A sensing elastic foam, characterized in that the sensing elastic foam (10) is an elastic dielectric unit, formed by stacking not less than 3 layers of porous grids, each layer of porous grids is composed of a core-shell The line structure units are interwoven and formed, and the core-shell line structure unit includes an elastic line unit (101), a sensing unit (102) and a wire unit (103), wherein the sensing unit (102) and the wire unit (103) is the core, and the elastic line element (101) is the shell.

2. The sensing elastic foam according to claim 1, wherein the line width of the elastic line unit (101) is 500-2000 microns, and the wall thickness is 100-2000 microns; the sensing unit (102) ) has a line width of 10-1500 μm, and the wire unit (103) has a line width of 10-1500 μm.

3 . The sensing elastic foam according to claim 1 , wherein the pattern type of the porous grid is one of criss-cross, triangle or hexagon. 4 .

4. A multi-channel coaxial extrusion additive manufacturing equipment, characterized in that it comprises an air compressor (1), an air line branch head (2), an electronic air pressure valve (3), a connecting air pipe (4), a loading A barrel (5), a multi-channel coaxial nozzle (6), an XYZ motion module (7), a clamp (8) and a body (9), the body (9) is provided with an XYZ motion module (7) ), the loading barrel (5) is fixed on the fuselage (9) by the clamp (8), and the air compressor (1) is connected to the loading barrel (5) and the The multi-channel coaxial spray head (6) is connected, and an electronic air pressure valve (3) is arranged between the air line branch head (2) and the loading barrel (5), which is used to control the extrusion of lines in different modes. The channel coaxial nozzle (6) is located just above the Y motion module (72).

5. The additive manufacturing equipment for multi-channel coaxial extrusion according to claim 4, wherein the multi-channel coaxial nozzle (6) comprises a first channel (61), a second channel (62) and The third channel (63), the three channels are inside the coaxial nozzle and are not connected to each other, and converge at the end of the nozzle to form a height difference, wherein the third channel (3) envelops the second channel (2), and the second channel ( 2) Envelop the first channel (1), and the overall size of the nozzle is 0.6-1.5 mm.

6. The multi-channel coaxial extrusion additive manufacturing equipment according to claim 5, characterized in that the loading barrel (5) comprises a sensing material barrel (51), a wire material barrel (52) and an elastic material barrel (52) a material cylinder (53), wherein the sensing material cylinder (51) is connected with the first channel (61), and the sensing material is extruded from the first channel (61);

The wire material barrel (52) is connected with the second channel (62), and the wire material is extruded from the second channel (62);

The elastic material cylinder (53) is connected with the third channel (63), and the elastic material is extruded from the third channel (3).

7. The additive manufacturing equipment for multi-channel coaxial extrusion according to claim 6, wherein the sensing material comprises carbon-based conductive liquid, carbon-based conductive paste, conductive polymer hydrogel, conductive ions One or more of the gels, the conductivity of the sensing material is 10 ² -10 ⁵ S/m, and the viscosity is 10 ² -10 ⁶ cps;

The wire material includes one or more of conductive ionic liquid, conductive polymer solution, and gallium indium tin alloy, and the wire material has a conductivity of 10 ⁵ to 10 ⁷ S/m and a viscosity of 1 to 10 ³ cps;

The elastic material includes one or more of polydimethylsiloxane, polyurethane, thermoplastic rubber, and thermoplastic resin, and has a viscosity of 10 ⁵ to 10 ⁹ cps.

8. The multi-channel coaxial extrusion additive manufacturing equipment of claim 4 performs line mode conversion and adjustment method, characterized in that, the line mode conversion and adjustment method is mainly by switching the opening and closing of the air pressure switches of the respective channels , so as to achieve the extrusion of several different mode lines:

①The third channel (63) is opened, the first channel (61) is opened, the second channel (62) is closed, and the sensing unit is formed by extrusion;

②The third channel (63) is opened, the first channel (61) is closed, the second channel (62) is opened, and the lead unit is formed by extrusion;

③ The third channel (63) is opened, the first channel (61) is closed, the second channel (62) is closed, and the elastic line unit is formed by extrusion;

The pressure range of each channel is 0-800 KPa, and the proportion of the line width occupied by the sensing material is adjusted by changing the pressure ratio of each channel.

9. The preparation method of the sensing elastic foam according to claim 1, characterized in that, comprising the following steps:

a. Install the multi-channel coaxial nozzle (6) on the fixture at the end of the Z motion module (73);

b. Load the elastic material, wire material and sensing material into the loading barrel (5) correspondingly, and connect the air pipe (4) and the shunt head (2) with the electronic air pressure valve (3), air compressor (1) Connection;

c. Generate the printing path through the control system, set the printing speed of the continuous additive manufacturing equipment to 0.1-50 mm/s, set the extrusion parameters of the three line modes,

①Elastic unit: Set the air pressure of the first channel (61) to 0 kPa, the air pressure of the second channel (62) to 0 kPa, and the air pressure of the third channel (63) to be 600-800 kPa;

②Sensing unit: Set the air pressure of the first channel (61) to 0 kPa, the air pressure of the second channel (62) to 350-400 kPa, and the air pressure of the third channel (63) to be 600-800 kPa;

③ Lead wire unit: Set the air pressure of the first channel (61) to 300-500 kPa, the air pressure of the second channel (62) to 0 kPa, and the air pressure of the third channel (63) to be 600-800 kPa;

d. Adjust the multi-channel coaxial nozzle (6) to 0.1-0.9 mm above the plane where the Y motion module (72) is located, and adjust the height to be 0.9 times the inner diameter of the multi-channel coaxial nozzle (6);

e. X-axis module and Y-axis module perform path interpolation at the same time, control the electronic air pressure valve of each channel to achieve the required ratio, complete the setting of printing path and extrusion line mode, and use shell elastic material with high energy storage mode The characteristics of the quantity are self-supporting, and the wire material or/and the sensing material are extruded internally; after the single-layer printing is completed, the Z-axis module is lifted to print the next layer;

f. After printing the grid structure, place it in a high temperature environment with a temperature greater than 80°C to fully cure it. Since the nodes are connected before curing, they can form good cross-links after curing, and the internal materials are constrained in The inner layer of the wire forms a coaxial elastic wire body structure, thereby constructing an elastic foam grid;

g. Insert external copper wires into the elastic foam grid obtained in step f to contact the wire material as lead wires, and then encapsulate and form with light-cured silica gel to obtain an elastic capacitive sensing grid structure.

10 . The method for preparing sensing elastic foam according to claim 9 , wherein, according to the curing conditions of different materials, auxiliary curing equipment including a thermal curing heating plate and a heating light source are selectively configured. 11 .