3D printing system and method having auto-tracking function

Abstract

The present invention relates to a 3D printing system and method having an auto-tracking function. The 3D printing system having an auto-tracking function, according to the present invention, comprises: a spray unit including a nozzle for spraying ink; a transport unit for transporting, in the horizontal or height direction, the spray unit or a stage on which an object to be printed is seated, according to a printing path set on the basis of shape information of a surface being printed; a displacement detection unit disposed at one side of the nozzle so as to detect, in real time, the height-directional displacement of an impact point at which ink ejected from the nozzle lands; a rotation unit for rotating the displacement detection unit about an axis of the nozzle; a nozzle transport unit for moving, on the basis of information about the height-directional displacement of the impact point obtained from the displacement detection unit, the nozzle in the height direction such that the distance between the point of impact and the nozzle is maintained constant; and a control unit, which controls, when printing is performed according to the printing path set by the transport unit, the rotation unit according to the printing direction so as to control the position of the displacement detection unit differently.

Description

3D printing system and method with auto-tracking function

[0001] The present invention relates to a 3D printing system and method having an auto-tracking function, and more specifically, to a 3D printing system and method having an auto-tracking function for printing a 3D structure on a printing surface of a 3D shape.

[0002] Bioprinting is a concept that combines 3D printing technology with biotechnology, which allows for the fabrication of artificial tissues or organs by stacking living cells into a desired shape. While the basic printing method is the same as general 3D printing, bioprinting differs in that it uses bioinks based on biocompatible polymers, biomaterials, and hydrogels to print living cells.

[0003] Recently, along with research on the development of improved bioinks, active research is being conducted on bioprinting technology that forms artificial tissues by directly spraying bioink onto affected areas of animals or humans.

[0004] However, when printing bioink directly onto a living organism, there is a problem in that it is difficult to form high-quality artificial tissue regardless of the characteristics of the bioink because the position of the living organism is unstable.

[0005] For example, even if the position of the affected area is stably fixed, minute displacement may occur due to the respiration of living organisms, etc.

[0006] These displacements cause large errors in the bioprinting process, which requires fine control ranging from tens of micrometers to several millimeters. Consequently, the bioink is not printed in the correct location and volume, which leads to a problem of reduced quality of the artificial tissue filled in the affected area.

[0007] Accordingly, a method was considered to measure the vertical displacement of the impact point where the bioink lands in real time from a sensor placed on one side of the nozzle, and to control the nozzle to move up and down according to the vertical displacement so that the distance between the nozzle and the impact point is maintained constant while printing.

[0008] However, since the sensor is positioned on one side of the nozzle and measures the displacement in an inclined direction relative to the curved impact point, it can measure the displacement at a point other than the impact point, so the distance between the nozzle and the impact point is not maintained at a constant, resulting in a problem of reduced printing accuracy.

[0009] The objective of the present invention is to solve such conventional problems. When printing is performed according to a printing path set by a transfer unit, a displacement sensing unit positioned on one side of the nozzle to measure the height-direction displacement of the impact point is controlled to be in a position perpendicular to the printing direction relative to the nozzle or in a position forward of the nozzle relative to the printing direction. By doing so, the height-direction displacement of the impact point can be accurately measured in real time, and printing can be performed by moving the nozzle to maintain a constant distance between the impact point and the nozzle. Accordingly, the invention provides a 3D printing system and a 3D printing method having an auto-tracking function that can increase printing precision even if the impact point moves due to breathing or other factors.

[0010] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below.

[0011] The above objective can be achieved by a 3D printing system having an auto-tracking function, characterized in that, according to the present invention, it comprises: a spraying unit including a nozzle for spraying ink; a transfer unit that transfers the spraying unit or a stage on which an object to be printed is placed in a horizontal or vertical direction according to a printing path set based on shape information of a surface to be printed; a displacement sensing unit disposed on one side of the nozzle that detects in real time the vertical displacement of a point of impact where ink sprayed from the nozzle lands; a rotation unit that rotates the displacement sensing unit around the axis of the nozzle; a nozzle transfer unit that moves the nozzle in a vertical direction so that the distance between the point of impact and the nozzle is maintained constant based on information regarding the vertical displacement of the point of impact obtained from the displacement sensing unit; and a control unit that controls the rotation unit according to the printing direction to control the position of the displacement sensing unit differently when printing is performed according to a printing path set by the transfer unit.

[0012] According to the 3D printing system and 3D printing method with an auto-tracking function of the present invention, there is an advantage in that the change in movement of the impact point is accurately measured in real time, so that printing precision can be maintained at a high level even if the impact point moves.

[0013] FIG. 1 is a drawing illustrating the configuration of a 3D printing system with an auto-tracking function according to one embodiment of the present invention.

[0014] Figure 2 is a photograph showing a laser sensor positioned behind the printing direction and a laser beam directed toward the point of impact on an inclined surface.

[0015] Figures 3 and 4 are diagrams illustrating that when a laser sensor is placed behind the printing direction and a laser is irradiated toward the point of impact on an inclined surface, a measurement error of the point of impact occurs.

[0016] FIG. 5 is a diagram illustrating an operation of performing printing by positioning a displacement sensing unit so that it is positioned perpendicular to the printing direction when performing printing according to an embodiment of the present invention along a printing path.

[0017] FIG. 6 is a diagram illustrating an operation of performing printing by positioning a displacement sensing unit so that it is positioned in front of the printing direction when performing printing according to another embodiment of the present invention along a printing path.

[0018] FIG. 7 is a diagram illustrating the sequence of a 3D printing method with an auto-tracking function according to an embodiment of the present invention.

[0019] One embodiment of the present invention discloses a 3D printing system having an auto-tracking function, comprising: a spraying unit including a nozzle for spraying ink; a transfer unit that transfers the spraying unit or a stage on which an object to be printed is placed in a horizontal or vertical direction according to a printing path set based on shape information of a surface to be printed; a displacement sensing unit disposed on one side of the nozzle that detects in real time the vertical displacement of a point of impact where ink sprayed from the nozzle lands; a rotation unit that rotates the displacement sensing unit around the axis of the nozzle; a nozzle transfer unit that moves the nozzle in a vertical direction so that the distance between the point of impact and the nozzle is maintained constant based on information regarding the vertical displacement of the point of impact obtained from the displacement sensing unit; and a control unit that controls the rotation unit according to the printing direction to control the position of the displacement sensing unit differently when printing is performed according to a printing path set by the transfer unit.

[0020] In this embodiment, the control unit can control the rotation unit so that the displacement sensing unit is positioned perpendicular to the printing direction with respect to the nozzle.

[0021] In this embodiment, the control unit can control the rotating part so that the displacement sensing part is positioned in front of the nozzle with respect to the printing direction.

[0022] In this embodiment, the ink may be a bioink.

[0023] In this embodiment, the printing surface is a body part, and the nozzle transfer unit can correct the height displacement of the body part.

[0024] In this embodiment, the displacement sensing unit may be a laser displacement sensor.

[0025] In this embodiment, a shape detection unit for identifying shape information of the surface to be printed may be further included.

[0026] Another embodiment of the present invention discloses a 3D printing method having an auto-tracking function, wherein, when printing is performed according to a printing path set in the printing step, the displacement detection unit is rotated around the axis of the nozzle according to the printing direction to change the position of the displacement detection unit.

[0027] In this embodiment, during the printing step, the displacement sensing unit may be rotated around the axis of the nozzle so that the displacement sensing unit is positioned perpendicular to the printing direction with respect to the nozzle.

[0028] In this embodiment, during the printing step, the displacement sensing unit may be rotated around the axis of the nozzle so that the displacement sensing unit is positioned in front of the nozzle with respect to the printing direction.

[0029] In this embodiment, the ink may be a bioink.

[0030] Specific details of the embodiments are included in the detailed description and drawings.

[0031] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the specification, like reference numerals refer to like components.

[0032] Hereinafter, the present invention will be described with reference to the drawings for explaining a 3D printing system with an auto-tracking function and a 3D printing method according to embodiments of the present invention.

[0033] FIG. 1 is a diagram illustrating the configuration of a 3D printing system with an auto-tracking function according to one embodiment of the present invention; FIG. 2 is a photograph showing a laser sensor placed behind the printing direction and a laser being irradiated toward the point of impact on an inclined surface; FIG. 3 and FIG. 4 are diagrams explaining that when a laser sensor is placed behind the printing direction and a laser is irradiated toward the point of impact on an inclined surface, a measurement error of the point of impact occurs; FIG. 5 is a diagram explaining the operation of performing printing while controlling the position of a displacement detection unit to be in a position perpendicular to the printing direction when performing printing along a printing path according to one embodiment of the present invention; FIG. 6 is a diagram explaining the operation of performing printing while controlling the position of a displacement detection unit to be in a position forward of the printing direction when performing printing along a printing path according to another embodiment of the present invention.

[0034] The 3D printing system with an auto-tracking function according to the present invention relates to a printing system that performs printing as a 3D structure on a surface of a 3D shape. For example, as shown in FIG. 1, it may be a 3D bioprinting system that treats a defective area, i.e., a affected area (15), existing in a part of the body (10) of a living organism such as an animal or a human by directly printing bioink on the affected area (15) to form artificial tissue on the affected area (15). Although the following description describes a 3D bioprinting system, the technical features of the present invention are not limited thereto and can be applied to all other 3D printing systems that form a 3D structure on a surface of a 3D shape.

[0035] A 3D printing system with an auto-tracking function according to one embodiment of the present invention may include a stage (110), a shape detection unit (120), a spraying unit (130), a transfer unit (140), a displacement detection unit (150), a rotation unit (160), a nozzle transfer unit (170), and a control unit (180).

[0036] A 3D printing system with an auto-tracking function according to one embodiment of the present invention can treat a defective area, i.e., a affected area (15), that exists in a part of the body (10) of a living organism such as an animal or a human by directly printing bioink on the affected area (15) to form artificial tissue on the affected area (15).

[0037] The stage (110) is a part on which the object to be printed is placed, and may be, for example, a part on which an animal or patient having a wound (15) requiring treatment or a part of the patient's body (10) is placed. Depending on the treatment target, the stage (110) may form a bed structure, or it may form a table structure so that a small animal or a part of the body (10) can be placed.

[0038] The shape detection unit (120) identifies the shape of the printing surface of an object placed on the stage (110). That is, in this embodiment, the shape of a lesion (15) existing on a part of a patient's body (10) or an animal placed on the stage (110) can be detected.

[0039] A non-contact scanning device known as the shape detection unit (120) above may be applied. The non-contact scanning method is a method of scanning an object using light, and models the three-dimensional shape of the object by irradiating the object with light using a laser or white light and measuring the time of the reflected light to quantify the distance.

[0040] That is, the shape detection unit (120) can generate modeled shape information of a three-dimensional shape corresponding to the defective part of the affected area (15) which is in the shape of an intaglio.

[0041] The shape detection unit (120) may be fixedly positioned on the upper side of the stage (110), or it may be configured to be installed on a separate transfer unit so that it can be moved on the upper side of the stage (110). For example, if the entire upper part of the stage (110) is the detection area, the entire shape of the affected part (15) can be detected while fixed on the upper side of the stage (110), and if a part of the upper part of the stage (110) is the detection area, the entire shape of the affected part (15) can be detected while moving on the upper side of the stage (110).

[0042] The shape detection unit (120) may be configured to be transported together with the spray unit (130) by the spray unit transport unit (140) described later.

[0043] In this embodiment, the shape detection unit (120) directly identifies the shape of the surface to be printed for an object placed on the stage (110), but the shape information of the object to be printed may be identified in advance and provided as 3D design data.

[0044] The spraying unit (130) is positioned above the stage (110) and may include a nozzle (135) that sprays ink toward the printing surface of an object placed on the stage (110).

[0045] In this embodiment, the spraying unit (130) sprays bioink toward the affected area (15) of the body (10). The bioink may contain a biomaterial or cell fluid. The biomaterial may be a biocompatible polymer or a hydrogel. The cell fluid may be a cell solution containing cells, a cell culture medium, and a hydrogel.

[0046] In the drawing, one spraying unit (130) is formed, but a plurality of spraying units (130) may be formed. For example, the spraying unit (130) may include a first spraying unit provided with a first nozzle for spraying biomaterial and a second spraying unit provided with a second nozzle for spraying cell fluid.

[0047] The above bioink may be made of materials with various characteristics depending on the location or type of artificial tissue being fabricated, and is not specifically limited thereto.

[0048] The transfer unit transfers the spray unit (130) horizontally (XY plane direction) or in a height direction (Z direction) according to a printing path generated based on shape information identified from the shape detection unit (120), or transfers the stage (110) horizontally or in a height direction. In this embodiment, the transfer unit (140) transfers the spray unit (130) horizontally or in a height direction according to a printing path generated based on shape information of the affected part (15) identified from the shape detection unit (120). That is, in FIG. 1, a spray unit transfer unit (140) that transfers the spray unit (130) horizontally or in a height direction is shown.

[0049] Although not illustrated, the transfer unit may be composed of a stage transfer unit that transfers the stage (110) in a horizontal or vertical direction. Alternatively, it may be composed of a combination of a spray unit transfer unit (140) and a stage transfer unit. For example, transfer in the X-axis and Y-axis directions may be composed of a spray unit transfer unit (140), and transfer in the Z-axis direction may be composed of a stage transfer unit.

[0050] When shape information of the printing surface obtained through the shape detection unit (120), that is, shape information modeled as a shape corresponding to the defect portion of the affected part (15), is obtained, a printing path can be created and set by the spraying unit (130).

[0051] For example, bio-ink is sprayed onto a predetermined impact point on the affected area (15) to pattern a spot or line shape. A nozzle (135) that is transported together with the spraying unit (130) is moved horizontally in the horizontal (X-axis) or vertical (Y-axis) direction, or a stage (110) is moved horizontally in the horizontal or vertical direction to collect the spot or line shape patterns and form a first layer of pattern. Then, the nozzle (135) of the spraying unit (130) is raised in the height (Z-axis) direction or the stage (110) is lowered in the height direction, and a stacking process is performed to build up a second layer of pattern, thereby forming the required three-dimensional structure.

[0052] That is, the printing path by the transfer of the injection unit (130) or the stage (110) can be set as a continuous printing path from the first injection point where the bio-ink is injected to the injection end point where the defective area of ​​the affected part (15) is completely filled with bio-ink, and at this time, from the injection point to the injection end point, the nozzle (135) is set to maintain a constant height from the point of impact located within the affected part (15).

[0053] The distance between the nozzle (135) and the point of impact can be set differently depending on the type of bioink used. For example, the distance between the first nozzle of the first spraying unit that sprays biomaterial and the second nozzle of the second spraying unit that sprays cell fluid can be set differently from each other.

[0054] The above-mentioned spray unit transfer section (140) may include a horizontal transfer section that transfers the spray unit (130) in a horizontal direction parallel to the stage (110), and a vertical transfer section that moves the spray unit (130) closer to or further away from the stage (110) in a vertical direction.

[0055] Likewise, the stage transfer unit may include a horizontal transfer unit that transfers the stage (110) in a horizontal direction and a vertical transfer unit that moves the stage (110) closer to or further away from the spray unit (130) in a vertical direction.

[0056] The above-mentioned transfer unit may utilize a general linear transfer structure, such as a linear motor or a structure combining a rotary motor and a ball screw; since the configuration of such a linear transfer structure is obvious to a person skilled in the art, a detailed description is omitted.

[0057] An animal or patient placed on the stage (110) experiences vertical displacement in the affected area (15) due to breathing, rigidity, convulsions, etc., which causes vertical displacement of the impact point where the bioink ejected from the nozzle (135) reaches. The displacement occurring at the impact point of the animal or patient may be vertical displacement (Z-axis) relative to the stage (110).

[0058] For example, when exhaling, the position of the impact point relatively decreases, and when inhaling, the position of the impact point relatively increases. If bio-ink is sprayed by moving the spray unit (130) or stage (110) along only the previously set printing path without considering the displacement of the affected area (15) in the height direction due to breathing, the distance between the impact point and the nozzle (135) changes in the height direction, so the problem arises that the bio-ink discharged from the nozzle (135) cannot be accurately sprayed to the impact point.

[0059] If the distance between the impact point and the nozzle (135) becomes closer than the set distance, an artificial tissue pattern smaller than the normal pattern may be formed, and if the distance between the impact point and the nozzle (135) becomes farther, the bioink diffuses and an artificial tissue pattern larger than the normal pattern may be formed.

[0060] Therefore, if the distance between the point of impact and the nozzle (135) on the printing path changes, the uneven formation conditions of the artificial tissue may cause a problem of quality degradation during the regeneration process of the artificial tissue.

[0061] To resolve this, the present invention detects the displacement in the height direction of the point of impact where ink is ejected from the nozzle (135) in real time, and based on this, moves the nozzle (135) to maintain the distance between the point of impact and the nozzle (135) at all times while performing printing. That is, the 3D bioprinting system according to the present embodiment can improve printing quality by detecting the displacement in the height direction of the point of impact caused by the respiration of an animal or patient in real time, and based on this, moves the nozzle (135) to maintain the distance between the point of impact and the nozzle (135) at all times while performing printing.

[0062] The displacement detection unit (150) is positioned on one side of the nozzle (135) and detects in real time the height direction displacement of the impact point where the ink ejected from the nozzle (135) lands. The impact point refers to the point where the ink (bio-ink) discharged from the nozzle (135) reaches the printing surface (the affected area (15)), and this can have an area of ​​tens of micrometers to several millimeters.

[0063] A laser displacement sensor may be applied to the displacement detection unit (150) above. The laser displacement sensor transmits a laser signal toward the point of impact and receives the reflected signal to measure the height displacement of the point of impact.

[0064] When the spray unit (130) is transported by the spray unit transport unit (140), the displacement detection unit (150) may be configured to be transported together with the spray unit (130). Since the displacement detection unit (150) is positioned on one side of the nozzle (135), it does not detect the displacement in the height direction of the impact point from the vertical upper side of the impact point, but rather measures the displacement in the inclination direction. In this case, as described later with reference to FIGS. 3 and 4, the displacement of the impact point may not be accurately measured.

[0065] The rotating part (160) rotates the displacement sensing part (150) around the axis of the nozzle (135). That is, the position of the displacement sensing part (150) relative to the nozzle (135) is not fixed, but can be changed by rotating it around the axis of the nozzle (135) by the rotating part (160).

[0066] The nozzle transfer unit (170) transfers the nozzle (135) in the vertical height direction based on information regarding the height direction displacement of the impact point obtained from the displacement detection unit (150) so that the distance between the impact point and the nozzle (135) is always maintained constant.

[0067] The nozzle transfer unit (170) is positioned on the aforementioned spray unit transfer unit (140), and can transfer the nozzle (135) in the height (Z-axis) direction parallel to the vertical transfer unit on the vertical transfer unit (140).

[0068] For the nozzle transfer unit (170), a general linear transfer structure such as a linear motor, a rotary motor, and a ball screw combination structure may be used, and since the configuration of such a linear transfer structure is obvious to a person skilled in the art, a detailed description is omitted.

[0069] Accordingly, in this embodiment, when irradiating the bioink onto the affected area (15) of the body (10), 3D printing can be performed by correcting the height-direction displacement of the impact point in real time by taking into account the change in height-direction displacement of the impact point caused by the breathing of the body (10).

[0070] When the control unit (180) performs printing by transporting the injection unit (130) or the stage (110) by the transport unit according to the set printing path, it controls the rotation unit (160) according to the printing direction to control the position of the displacement detection unit (150) differently. Although the drawing shows that the control unit (180) controls only the rotation unit (160), the control unit (180) can control all operations related to the 3D printing system. That is, the control unit (180) can control the operation of the shape detection unit (120), injection unit (130), transport unit, displacement detection unit (150), nozzle transport unit (170), etc.

[0071] FIGS. 3 and 4 illustrate a case where printing is performed by moving the nozzle (135) from left to right on a curved printing surface of a 3D shape, and the displacement sensing unit (150) is located behind the nozzle (135).

[0072] When printing is performed on the highest point of a printing surface that is curved in a 3D shape as shown in FIG. 3, the sensor signal of the displacement detection unit (150) can be accurately directed toward the point of impact. That is, even if the displacement detection unit (150) is positioned behind the nozzle (135) with respect to the printing direction, on a rising inclined surface, the sensor signal of the displacement detection unit (150) can be accurately directed toward the point of impact on the inclined surface.

[0073] However, as shown in FIG. 4, when the nozzle (135) moves to the right, the sensor signal of the displacement detection unit (150) does not reach the point of impact vertically below the nozzle (135) with respect to the inclined surface inclined downward in the printing direction (from left to right), but the sensor signal of the displacement detection unit (150) may reach the bottom surface to the right of the point of impact. In FIG. 2, it can be seen that in the situation of FIG. 4, the actual laser displacement sensor signal is directed to the right of the point of impact rather than to the point of impact.

[0074] Therefore, in this case, the displacement detection unit (150) fails to measure the height-direction displacement of the impact point vertically below the current nozzle (135) position and instead measures the height-direction displacement of another point, causing the measurement value to change suddenly. Consequently, the nozzle transfer unit (170) transfers the nozzle (135) based on the incorrectly measured value, which may result in the distance between the nozzle (135) and the impact point not being maintained constant, thereby causing a problem of reduced printing precision.

[0075] Accordingly, in the present invention, when the control unit (180) performs printing according to the set printing path, the position of the displacement detection unit (150) is controlled differently according to the printing direction so that no error occurs in the measurement value measured by the displacement detection unit (150).

[0076] For example, as illustrated in FIG. 5, the control unit (180) can control the rotation unit (160) so that the displacement detection unit (150) is positioned perpendicular to the printing direction with respect to the nozzle (135). Here, the printing direction does not mean the direction in which ink is discharged from the nozzle (135), but rather the direction in which ink is continuously printed along the printing path while transporting the nozzle (135) or the stage (110).

[0077] When printing is performed by changing the printing direction by the transfer unit along the printing path indicated by the dotted line in the drawing, at each point where the printing direction changes, the displacement detection unit (150) is controlled to be in a position perpendicular to the printing direction with respect to the nozzle (135), thereby preventing an error in the displacement measurement value when the displacement detection unit (150) is positioned behind the printing direction as described with reference to FIG. 4.

[0078] This is because if the displacement detection unit (150) is positioned in a direction perpendicular to the printing direction, the sensor signal of the displacement detection unit (150) reaches the point of impact regardless of the inclined surface.

[0079] Alternatively, as shown in FIG. 6, the control unit (180) can control the rotation unit (160) so that the displacement detection unit is positioned in front of the nozzle (135) with respect to the printing direction. When printing is performed by changing the printing direction by the transfer unit along the printing path indicated by the dotted line as shown in FIG. 6, the displacement detection unit (150) is controlled to be positioned in front of the nozzle (135) with respect to the printing direction at each point where the printing direction changes, thereby preventing an error in the displacement measurement value from occurring when the displacement detection unit (150) is positioned behind the printing direction as described with reference to FIG. 4.

[0080] Hereinafter, a 3D printing method with an auto-tracking function according to the present invention will be described.

[0081] FIG. 7 is a diagram illustrating the sequence of a 3D printing method with an auto-tracking function according to an embodiment of the present invention.

[0082] The 3D printing method with an auto-tracking function according to the present invention may include the step of identifying the shape of the surface to be printed (S210), the step of generating a printing path (S220), and the step of printing (S230).

[0083] In the step (S210) of determining the shape of the surface to be printed, the shape of the surface to be printed of the object to be printed prepared on the stage (110) is determined. In this embodiment, the shape of the affected area (15) existing on a part of the body (10) or animal prepared on the stage (110) is determined. That is, the shape detection unit (120) can be used to generate and model the three-dimensional shape information corresponding to the defective part of the affected area (15) in the form of an intaglio. Alternatively, the shape information of the object may be determined in advance and provided as 3D design data before the object to be printed is placed on the stage (110).

[0084] Next, a printing path is generated based on the shape information of the surface to be printed (S220). That is, in this embodiment, a printing path in which ink is printed is set based on the shape information of the affected area (15) obtained by the shape detection unit (120). The printing path thus set can be a continuous printing path from the initial point of injection where bio-ink is sprayed toward the affected area (15) to the end point of injection where the defective area of ​​the affected area (15) is completely filled with bio-ink.

[0085] At this time, when printing is performed along the printing path from the injection point to the injection end point, the distance between the nozzle (135) and the point of impact can be set to be maintained at a constant distance. The distance between the nozzle (135) and the point of impact can be set differently depending on the type of bioink used and the degree of defect in the affected area (15).

[0086] Next, the printing step (S230) performs printing by moving the injection unit (130) or the stage (110) in a horizontal or vertical direction according to the generated printing path. That is, in this embodiment, bio-ink is injected from the nozzle (135) according to the generated printing path to form artificial tissue.

[0087] For example, the nozzle (135) of the spraying unit (130) is moved horizontally in the horizontal (X-axis) or vertical (Y-axis) direction, or moved vertically in the height (Z-axis) direction, and the spraying unit (130) is moved along a set printing path and bio-ink is sprayed toward the affected area (15).

[0088] Thus, the displacement in the height direction of the impact point is measured in real time using a displacement detection unit (150) that detects in real time the displacement in the height direction of the impact point where the ink sprayed from the nozzle (135) lands while spraying ink. That is, in this embodiment, while spraying bio-ink toward the affected area (15), the process includes compensating for the height direction position of the nozzle (135) by taking into account the change in height direction displacement of the affected area (15) due to breathing, etc.

[0089] That is, the printing step (S230) may include a step of detecting the displacement in the height direction of the impact point in real time and a step of correcting the height direction position of the nozzle (135) so that the distance between the impact point and the nozzle (135) is maintained constant.

[0090] At this time, in the printing step (S230) described with reference to FIGS. 5 and 6, when printing is performed according to a set printing path, the position of the displacement detection unit (150) is changed by rotating the displacement detection unit (150) around the axis of the nozzle (135) according to the printing direction. At this time, when the displacement detection unit (150) acquires the displacement of the impact point formed as a 3D curved surface in real time, the position of the displacement detection unit (150) is changed to a point where no error occurs in the measurement value.

[0091] For example, whenever the printing direction changes, it is preferable to change the position of the displacement detection unit (150) by rotating the displacement detection unit (150) around the axis of the nozzle (135) so that the displacement detection unit (150) is positioned perpendicular to the printing direction with respect to the nozzle (135) or is positioned further forward than the nozzle (135).

[0092] After 3D bioprinting is completed and a certain amount of time has passed, the cells contained in the bioink receive oxygen and nutrients through the diffusion of body fluids until new blood vessels are formed in most tissues or organs. Then, as blood vessels enter the body and blood supply is established, the cells proliferate and differentiate to form new tissues, and the biomaterial decomposes and disappears during this time.

[0093] The scope of the present invention is not limited to the embodiments described above but may be implemented in various forms of embodiments within the scope of the appended claims. It is deemed that the scope of the claims of the present invention includes various modifications that are possible by anyone with ordinary knowledge in the technical field to which the invention pertains, without departing from the essence of the invention claimed in the claims.

Claims

1. A spraying unit including a nozzle for spraying ink; A transfer unit that transfers the injection unit or the stage on which the object to be printed is placed in a horizontal or height direction according to a printing path set based on shape information of the surface to be printed; A displacement sensing unit disposed on one side of the nozzle and detecting in real time the height-direction displacement of the impact point where the ink sprayed from the nozzle lands; A rotating part that rotates the above displacement sensing part around the axis of the nozzle; A nozzle transfer unit that moves the nozzle in the height direction so that the distance between the impact point and the nozzle is maintained constant, based on information regarding the height direction displacement of the impact point obtained from the displacement detection unit; and A 3D printing system having an auto-tracking function, comprising a control unit that controls the position of the displacement sensing unit differently by controlling the rotation unit according to the printing direction when performing printing according to a printing path set by the transfer unit.

2. In Paragraph 1, The above control unit is a 3D printing system having an auto-tracking function that controls the rotation unit so that the displacement sensing unit is positioned perpendicular to the printing direction with respect to the nozzle.

3. In Paragraph 1, The above control unit is a 3D printing system having an auto-tracking function that controls the rotation unit so that the displacement sensing unit is positioned in front of the nozzle with respect to the printing direction.

4. In Paragraph 1, The above ink is a bioink, a 3D printing system with an auto-tracking function.

5. In Paragraph 4, The above-mentioned printing surface is a body part, and the above-mentioned nozzle transfer unit is a 3D printing system having an auto-tracking function that corrects the height-direction displacement of the body part.

6. In Paragraph 1, The above displacement sensing unit is a laser displacement sensor, a 3D printing system with an auto-tracking function.

7. In Paragraph 1, A 3D printing system with an auto-tracking function that further includes a shape detection unit for identifying shape information of the surface being printed.

8. Step of determining the shape of the surface to be printed; A step of generating a printing path based on shape information of the surface to be printed; and The method includes the step of printing while moving a spraying unit including a nozzle that sprays ink according to a generated printing path, or a stage on which an object to be printed is placed, in a horizontal or vertical direction. The above printing step is, A step of detecting in real time the height direction displacement of the impact point using a displacement detection unit disposed on one side of the nozzle and detecting in real time the height direction displacement of the impact point where the ink sprayed from the nozzle lands; and Based on information regarding the height-direction displacement of the impact point obtained from the displacement detection unit, the method includes the step of moving the nozzle in the height direction so that the distance between the impact point and the nozzle is maintained constant. A 3D printing method having an auto-tracking function that changes the position of the displacement sensing unit by rotating the displacement sensing unit around the axis of the nozzle according to the printing direction when performing printing according to a printing path set in the printing step.

9. In Paragraph 8, A 3D printing method having an auto-tracking function that rotates the displacement sensing unit around the axis of the nozzle so that, in the printing step, the displacement sensing unit is positioned perpendicular to the printing direction with respect to the nozzle.

10. In Paragraph 8, A 3D printing method having an auto-tracking function that rotates the displacement sensing unit around the axis of the nozzle so that the displacement sensing unit is positioned ahead of the nozzle with respect to the printing direction during the printing step.

11. In Paragraph 8, The above ink is a 3D printing method with an auto-tracking function that is a bioink.

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