KR101933985B1 - Soft sensor using 3D printing, and manufacturing method of the same, and wearable apparatus having the same - Google Patents

Abstract

A soft sensor using 3D printing according to the present invention is characterized in that two first and second elastic layers having different viscosities are formed and a conductive grease is applied between the first elastic layer and the second elastic layer by 3D printing using a syringe, It is possible to form microchannels of various sizes, numbers and shapes without being restricted by the size or shape of the sensor. In addition, since a mold is not used, a soft sensor having a thinner thickness than that of a mold can be manufactured. In addition, since the conductive grease is 3D-printed using a syringe, the thickness of the microchannel can be minimized. Further, the microchannel formed between the first stretchable layer and the second stretchable layer is formed of conductive grease and maintains the state of gel or sol, so that the stretchability of the microchannel can be secured. Further, since the channel pattern is designed using the CAD / CAM, the channel pattern can be easily designed and modified.

Description

Technical Field [0001] The present invention relates to a soft sensor using 3D printing, a manufacturing method thereof, and a wearable device using the soft sensor, and a manufacturing method of the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft sensor using 3D printing, a method of manufacturing the same, and a wearable device using the soft sensor. More particularly, the present invention relates to a soft sensor, A method of manufacturing the same, and a wearable device using the same.

In general, a soft sensor is a sensor that can measure elasticity, flexibility, and displacement or force by forming an electrode formed of a conductive material in a material having elasticity and flexibility such as silicon or PDMS. A conventional soft sensor is formed by forming a microchannel inside a stretchable material such as silicon or PDMS and injecting a conductive fluid into the microchannel, and by changing the shape of the inner microchannel It is a sensor that measures force and measures force. In recent years, as the range of applications such as wearable devices is expanding, demands for flexible and flexible soft sensors are increasing.

In a conventional method for fabricating a soft sensor, a mold for microchannel molding is manufactured, a silicon material is filled in the mold, the microchannel shape is formed by hardening, and a sensor is manufactured through a post-process.

However, in the conventional method of manufacturing a soft sensor, since the manufacturing process is complicated and complicated, there is a problem that the performance of the sensor is influenced by the proficiency of the manufacturer. Also, a large-sized sensor can not be manufactured.

Korean Patent Publication No. 10-2016-0136894

It is an object of the present invention to provide a soft sensor using 3D printing which can be easily manufactured and improved in performance, a method of manufacturing the same, and a wearable apparatus using the same.

A method of fabricating a soft sensor using 3D printing according to the present invention comprises: applying a first stretchable material onto a base substrate to form a first stretchable layer; Applying a second stretchable material over the first stretchable layer to form a second stretchable layer having a lower viscosity than the first stretchable layer before the first stretchable layer is hardened; Before the first stretchable layer and the second stretchable layer are hardened, a needle of a syringe whose movement is controlled by a CNC equipment passes the second stretchable layer and a conductive grease is printed on the first stretchable layer in a preset channel pattern Thereby forming a microchannel; And detaching the first elastic layer and the second elastic layer from the base substrate to form a soft sensor having a structure in which the microchannel is embedded in the first elastic layer and the second elastic layer when the first elastic layer and the second elastic layer are hardened .

A soft sensor using 3D printing according to the present invention comprises: a first elastic layer formed of a first elastic material; A second stretchable layer formed by applying a second stretchable material on the first stretchable layer and formed to have a viscosity lower than that of the first stretchable layer; And a microchannel formed between the first elastic layer and the second elastic layer and having conductive grease printed in a predetermined channel pattern by a syringe whose movement is controlled by a CNC equipment.

A soft sensor using 3D printing according to the present invention comprises: a stretchable sheet having first and second stretchable layers having different viscosities laminated; A plurality of microchannels formed between the first elastic layer and the second elastic layer inside the elastic sheet and formed by 3D printing of conductive grease in a predetermined pattern through a syringe whose movement is controlled by a CNC equipment; And electrodes connected to the microchannels.

A soft sensor using 3D printing according to the present invention is characterized in that two first and second elastic layers having different viscosities are formed and a conductive grease is applied between the first elastic layer and the second elastic layer by 3D printing using a syringe, It is possible to form microchannels of various sizes, numbers and shapes without being restricted by the size or shape of the sensor.

In addition, since a mold is not used, a soft sensor having a thinner thickness than that of a mold can be manufactured.

In addition, since the conductive grease is 3D-printed using a syringe, the thickness of the microchannel can be minimized.

Further, the microchannel formed between the first stretchable layer and the second stretchable layer is formed of conductive grease and maintains the state of gel or sol, so that the stretchability of the microchannel can be secured.

Further, since the channel pattern is designed using the CAD / CAM, the channel pattern can be easily designed and modified.

1 is a view showing a soft sensor using 3D printing according to an embodiment of the present invention.
FIG. 2 is a schematic view illustrating a method of manufacturing a soft sensor using 3D printing according to an embodiment of the present invention. Referring to FIG.
3 shows an example of a wearable device to which a soft sensor according to an embodiment of the present invention is applied.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a view showing a soft sensor using 3D printing according to an embodiment of the present invention.

Referring to FIG. 1, a soft sensor using 3D printing according to an embodiment of the present invention includes a stretchable sheet 10 and a microchannel 20 formed inside the stretchable sheet 10.

The stretchable sheet 10 includes a first stretchable layer 11 and a second stretchable layer 12. The first stretchable layer 11 and the second stretchable layer 12 are separately formed and stacked in a vertical direction.

The first stretchable layer (11) is a layer formed of the first stretchable material by applying a first stretchable material. The first stretchable material is a nonconductive material having stretchability and flexibility. The first stretchable material is exemplified by using silicon.

The second elastic layer 12 is a layer formed of the second elastic material by applying a second elastic material. The second stretchable material is a nonconductive material having stretchability and flexibility. In this embodiment, silicon is used as the second stretchable material, and the second stretchable material and the second stretchable material are the same material. If the first stretchable material and the second stretchable material are made of the same silicone, the silicone can be hardened into a monolithic sheet. However, the present invention is not limited to this, and it is of course possible to use the same material other than silicon or to use different materials.

The second elastic layer (12) is formed to have a lower viscosity than the first elastic layer (11). In the present embodiment, the first elastic layer 11 and the second elastic layer 12 are made of the same elastic material, and the first elastic layer 11 is made of a thickening material agent, and the second elastic layer 12 uses a thinning agent to lower the viscosity of the elastic material. However, the present invention is not limited to this, and the difference in viscosity between the first elastic layer 11 and the second elastic layer 12 may be set according to the viscosity of the first elastic material and the second elastic material, It is also possible to add and adjust the viscosity of the first elastic material and the viscosity of the second elastic material at different ratios.

The microchannel (20) is formed between the first elastic layer (11) and the second elastic layer (12). The microchannel 20 is formed by stacking a needle 31 of a syringe 30 coupled to a CNC fixture on the second elastic layer 12 after the second elastic layer 12 is laminated on the first elastic layer 11, (12), and scanning the conductive layer with conductive grease on the first stretchable layer (11) in a predetermined channel pattern.

The conductive grease is exemplified by using a carbon conductive grease. The carbon conductive grease is of gel or sol type and is easy to form the microchannel.

FIG. 2 is a schematic view illustrating a method of manufacturing a soft sensor using 3D printing according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 2, a method of manufacturing a soft sensor using 3D printing according to an embodiment of the present invention will now be described.

Referring to FIG. 2A, the first stretchable layer 11 is formed on the base substrate 2 by applying the first stretchable material. At this time, the first elastic layer 11 is a layer formed with a viscosity higher than that of the second elastic layer 12 described later, and is not hardened.

The base substrate 2 is formed in such a shape that the first stretchable layer 11 can be held in a state in which it is not hardened. That is, the base substrate 2 is formed into a bowl shape having a side wall portion.

Referring to FIG. 2B, the second stretchable material 12 is applied on the first stretchable layer 11 to form the second stretchable layer 12. Wherein the second elastic layer (12) is laminated on the first elastic layer (11) to form the elastic sheet (10), wherein the first elastic layer (11) and the second elastic layer Do not.

Referring to FIG. 2C, the carbon conductive grease 21 is injected into the elastic sheet 10 using the injector 30. At this time, the needle 31 of the syringe 30 passes through the second elastic sheet 12, and the needle 31 injects the carbon conductive grease 21 onto the first elastic layer 11 do. Therefore, the carbon conductive grease 21 can be injected only onto the first elastic layer 11 having a relatively high viscosity.

Because the second elastic layer 12 is low in viscosity, it is easy for the needle 31 of the syringe 30 to pass through and the needle 31 is pressed against the second elastic layer 12). That is, since the viscosity of the second elastic layer 12 is very low, no movement traces or through holes of the needle 31 remain in the second elastic layer 12 when the needle 31 is moved, Can be.

Since the first elastic layer 11 has a relatively high viscosity, it is easy to print the channel pattern with the carbon conductive grease 21 injected from the needle 31 of the injector 30. The height of the needle 31 of the syringe 30 can be controlled according to the control of a three-axis controller of the CNC equipment to be described later.

The syringe (30) is filled with the carbon conductive grease (21). The syringe 30 is coupled to the CNC equipment and is controlled to be movable in three axial directions. The CNC equipment corresponds to a 3D printer, and may include a three-axis controller, a scan controller, a microscope, and the like.

The syringe 30 scans the carbon conductive grease 21 while moving in a predetermined path under the control of the triaxial controller. The paths in the three axial directions are respectively set according to the channel pattern.

The channel pattern is designed by a user in a desired microchannel pattern using CAD. Since the channel pattern is designed using a CAD, it can be easily designed in various shapes, sizes, and numbers, and it is easy to modify. The shape, size, and number of the channel patterns are set according to the usage, size, and the like of the soft sensor.

After designing the channel pattern, a G code is generated using CAM, a G code is modified using a simulator, and then the signal is transmitted to the triaxial controller. Therefore, the channel pattern has an advantage of being easily designed and modified using a CAD / CAM. Further, there is an advantage that it is not necessary to produce a separate mold for forming the channel pattern.

When the carbon conductive grease is injected into the syringe 30, the shape and size of the microchannel and the characteristics of the soft sensor can be controlled by adjusting process parameters. The process parameters include the inner diameter of the needle of the syringe 30, the scan pressure of the syringe 30, and the transfer speed of the syringe. By appropriately combining the process variables, the shape, size and characteristics of the desired microchannel can be adjusted. The process variables may be set by the user directly or may be set to optimal conditions by a preset program. In this embodiment, the feeding speed of the syringe was set at 300 mm / min, and the scanning pressure of the syringe was set at 25 psi.

The smaller the inner diameter of the needle of the syringe 30, the smaller the width and height of the cross section of the microchannel 20. The performance of the soft sensor can be changed according to the width and height of the cross section of the microchannel 20. [ The smaller the width and height, the greater the sensitivity of the soft sensor. The syringe 30 is detachably coupled to the CNC facility and is replaceable. It is also possible to replace the needle of the syringe 30 only.

As the pressure for scanning the carbon conductive grease in the syringe 30 is higher, the width and height of the cross section of the microchannel 20 increases. The pressure of the syringe 30 is controlled by the dispensing controller.

As the feed rate of the syringe 30 increases, the diameter of the cross section of the microchannel 20 decreases. Since the microchannel 20 prints the carbon conductive grease on the unfixed silicon, the cross section of the microchannel 20 is formed into a circular shape, and the diameter becomes smaller as the feeding speed becomes higher. The feed rate of the syringe 30 is controlled by the triaxial controller.

After the microchannel 20 is formed, the needle 31 of the syringe 30 is moved upward and is withdrawn from the second elastic layer 12.

When the needle 31 of the syringe 30 is pulled out of the second elastic layer 12, the second elastic layer 12 has a low viscosity, so that the place where the needle 31 has penetrated can be immediately buried have.

Thereafter, when the first elastic layer 11 and the second elastic layer 12 are hardened, the base substrate 2 can be removed to complete the soft sensor.

The soft sensor fabricated in this way is advantageous in that since the microchannel 20 maintains a gel or sol state between the first elastic layer 11 and the second elastic layer 12, The elasticity of the elastic member 20 can be maintained.

In addition, the soft sensor can be made thinner than the case of using a mold.

In addition, the soft sensor can easily design and change the channel pattern using CAD / CAM.

Meanwhile, FIG. 3 shows an example of a wearable device to which a soft sensor according to an embodiment of the present invention is applied.

Referring to FIG. 3, a plurality of microchannels 20 are formed on one stretchable sheet 10. That is, the one stretchable sheet 10 may be cut into a shape suitable for a part to be worn. Here, an example will be described in which the sensor is used as a shoe sensor for cutting out the foot sole and measuring the ground reaction force.

As described above, since the plurality of microchannels 20 can be formed at one time by using 3D printing, it is easy to manufacture a sensor having a large size.

In addition, since molds for forming a plurality of channel patterns are not required, manufacturing can be simplified and cost can be reduced.

Since the soft sensor using 3D printing according to the present invention is capable of forming microchannels 20 of various numbers and shapes because the sensor is not limited in size and the thickness of the sensor is very thin and elastic, It is easy to apply to joints such as shoulders, ankles, wrists, and fingers that have complicated movements.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: stretchable sheet 11: first stretchable layer
12: second elastic layer 20: microchannel
30: Syringe 31: Needle

Claims (10)

Applying a first stretchable material over the base substrate to form a first stretchable layer;
Forming a second stretchable layer having a lower viscosity than the first stretchable layer by applying a second stretchable material over the first stretchable layer before the first stretchable layer is hardened to form a second stretchable layer having a lower viscosity than the first stretchable layer, Forming a stretchable sheet laminated and in which the first stretchable layer and the second stretchable layer are not intermixed with each other;
Before the first stretchable layer and the second stretchable layer are hardened, a conductive grease is injected into the stretchable sheet by using a syringe whose movement is controlled by a CNC equipment, and printing is performed in a preset channel pattern, ; ≪ / RTI >
When the first elastic layer and the second elastic layer are hardened, they are detached from the base substrate to maintain a state of gel or sol in the first elastic layer and the second elastic layer so that the micro- Forming a soft sensor of the structure,
Wherein the first elastic layer is formed by adding a viscosity increasing agent to the first elastic material,
Wherein the second elastic layer is formed by adding a thinning agent to the second elastic material to lower the viscosity,
In the step of forming the microchannel,
The needle of the syringe penetrating the second elastic layer, injecting the conductive grease onto the first elastic layer,
And printing the channel pattern and then moving the needle of the syringe upwardly and pulling it out of the second elastic layer, wherein the spot through which the needle has penetrated is filled. The method according to claim 1,
Wherein the conductive grease is made by 3D printing using carbon conductive grease. delete The method according to claim 1,
Wherein the first stretchable material and the second stretchable material are fabricated using 3D printing using silicon. The method according to claim 1,
The channel pattern may include:
A method of manufacturing a soft sensor using 3D printing, which is designed using CAD, coded using CAM, and transmitted to the CNC equipment. The method according to claim 1,
The shape, size, and performance of the micro-
Wherein the inner diameter of the needle of the syringe, the syringe pressure of the syringe, and the transfer speed of the syringe are controlled by 3D printing. A first stretchable layer formed of a first stretchable material;
A second stretchable layer formed by applying a second stretchable material on the first stretchable layer and formed to have a viscosity lower than that of the first stretchable layer;
Conductive grease is printed in a predetermined channel pattern by a syringe formed between the first elastic layer and the second elastic layer and controlled to be moved by a CNC equipment so that a gap between the first elastic layer and the second elastic layer A microchannel having elasticity by maintaining a state of gel or sol in the microchannel,
Wherein the first elastic layer is formed by adding a viscosity increasing agent to the first elastic material,
And the second elastic layer is formed by adding a thinning agent to lower the viscosity of the second elastic material. The method of claim 7,
The conductive grease is made by 3D printing using carbon conductive grease. delete A stretchable sheet in which first and second stretchable layers having different viscosities are laminated;
Conductive grease is formed by 3D printing in a predetermined pattern through a syringe formed between the first elastic layer and the second elastic layer inside the elastic sheet and controlled to move by a CNC equipment, A plurality of microchannels having elasticity by maintaining a state of gel or sol between the first elastic layer and the second elastic layer;
And electrodes connected to the microchannels,
Wherein the first elastic layer is formed by adding a viscosity increasing agent to the first elastic material,
Wherein the second elastic layer is formed by adding a thinning agent for lowering the viscosity of the second elastic material to the wearable device.

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