Patent Description:
A 3D printer includes a frame constituting the XYZ axis, and a nozzle capable of spraying and stacking a liquid or powder material in a flat form so as to form a three dimensional form. The 3D printer encompasses, for example, Cartesian-, Mendel-, Delta-, Core XY-style 3D printers, etc. depending on a printing method. In the Cartesian-style 3D printer, a bed moves in the X and Y axes, and a nozzle moves in the Z axis direction to implement 3D printing. In the Mendel-style 3D printer, a bed moves in the Z axis direction and a nozzle moves in the X, Y axes to implement 3D printing. In the Delta-style 3D printer, a nozzle moves in the X, Y, Z axes to implement 3D printing. The Core XY-style 3D printer, a nozzle moves in the X, Y axis directions by a belt connected by two motors and a bed moves in the Z direction. Recently, the Core XY-style 3D printer, which is capable of controlling the position of the nozzle most precisely, is widely used.

A bio-3D printer is a device that has been structurally modified so as to three-dimensionally create a living tissue or an organ by discharging a biomaterial through the nozzle of the 3D printer.

This bio-3D printer includes a dispenser-type for discharging the biomaterial. The bio-3D printer fills the nozzle with a viscous biomaterial such as collagen, gelatin, etc. This adopts a method that connects a pneumatic system to the nozzle filled with the viscous biomaterial to discharge the biomaterial while pushing it out.

An example of this bio-3D printer is disclosed in <CIT>. Meanwhile, when the viscosity is low depending on the type of biomaterials employed in the bio-3D printer, the dispenser-type nozzle as described above cannot be used. When the fluidity of the biomaterial resulting from its low viscosity is excessively high, the dispenser-type nozzle adopting an extrusion method to squeeze the material cannot be used because it is difficult to control the fluid. In this case, it is necessary to use a valve-type dispenser which controls and sprays a small amount of biomaterial in s droplet form. When outputting a biomaterial with high fluidity, a method of layered cross-liking or mixed crosslinking can be used while spraying the biomaterial onto a substrate in a mist form by employing a nebulizer, for example, as disclosed in <CIT>.

However, when employing the nebulizer as the above-mentioned, the nebulizer must be configured to downwardly spray the biomaterial toward the substrate. Most biomaterials used in the bio-3D printer are expensive. However, in the case of a downward spraying-type nebulizer, there is a problem that the biomaterial accommodated in the nebulizer unexpectedly leaks downwards due to gravity while the output thereof is stopped. In general, it takes <NUM> minutes to <NUM> minutes to output the biomaterial form the bio-3D printer. In this case, when conducting a study in the order of output --> incubation --> output --> incubation --> observation, it may take more than <NUM> weeks to output the biomaterial. In this process, when the biomaterial accommodated in the nebulizer leaks unexpectedly, there is a problem that not only economic loss but also fatal errors may occur.

<CIT> discloses a bio-3D printer that dispenses biomaterial and also medical adhesive. In one embodiment the bio-3D printer comprises a leakage prevention systema for the medical adhesive.

The present disclosure is contrived to solve the aforementioned problem, providing a bio-3D printer comprising an output unit constituted by a leakage prevention system for a downward spraying-type nebulizer for stacking a biomaterial of the bio-3D printer including a nebulizer that is configured to spray the biomaterial downwards so as to prevent the biomaterial from leaking.

In order to achieve the object as mentioned above, provided is a bio-3D printer comprising an output unit constituted by a leakage prevention system for a downward spraying-type nebulizer for stacking a biomaterial of the bio-3D printer according to the present disclosure, wherein the system constituting an output unit of the bio-3D printer includes:.

The leakage prevention system for a downward spraying-type nebulizer for stacking a biomaterial of the bio-3D printer according to the present disclosure is suitable to apply an air pressure below atmospheric pressure within a preset range to the nebulizer during a time when the nebulizer is not operated, so as to provide a prevention effect of leakage of biomaterial due to gravity.

Hereinafter, the preferred embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

<FIG> is a structural view of a system according to a preferred embodiment of the present disclosure. <FIG> is an exploded perspective view of the configuration in the vicinity of a nebulizer. <FIG> is an enlarged view of the configuration in the vicinity of the nebulizer as shown in <FIG>. <FIG> is a partial cross-sectional view taken long line IV - VI as shown in <FIG>.

Referring to <FIG>, a leakage prevention system for a downward spraying-type nebulizer for stacking a biomaterial of a bio-3D printer (hereinafter, referred to as "leakage prevention system for a nebulizer") includes a cartridge <NUM>, a nebulizer <NUM>, a vacuum cap <NUM>, a distributor <NUM>, a vacuum generating module <NUM>, a compressor <NUM>, a controller <NUM> and a drying fan <NUM>.

The leakage prevention system for a nebulizer is a system constituting an output unit of the bio-3D printer.

The nebulizer cartridge <NUM> is fixed to a housing <NUM> of the bio-3D printer. The nebulizer cartridge <NUM> is a rod-shaped structure, including a plurality of installation holes <NUM> formed to penetrate the cartridge in a direction perpendicular to the ground so as to detachably install the plurality of nebulizers <NUM>. The drying fan <NUM> blowing air to promote drying of the biomaterial <NUM> sprayed from the nebulizer <NUM> may be installed on a side surface of the nebulizer cartridge <NUM>.

The nebulizer <NUM> is a device that downwardly sprays the biomaterial <NUM> into a form of mist toward a substrate. The nebulizer <NUM> is installed in a state partially accommodated in the installation hole <NUM>. The nebulizer <NUM> may be firmly fixed to the nebulizer cartridge <NUM> with a fixing member <NUM> to be screwed in a lateral direction of the installation hole <NUM>. The nebulizer <NUM> includes a space accommodating the biomaterial <NUM> at an upper portion thereof. The nebulizer has a vibrating membrane <NUM> installed at a lower portion thereof. The nebulizer <NUM> employed in the present disclosure is a vibrating membrane type. The vibrating membrane <NUM> vibrates at a high frequency in response to a signal of the controller <NUM> to be described later so that the biomaterial <NUM> accommodated in the nebulizer <NUM> is divided into a mist form and sprayed downwards. The principal of the nebulizer <NUM> employed in the present disclosure is the same as that of a known vibrating membrane-type nebulizer. A particular size of the biomaterial <NUM> sprayed in the nebulizer <NUM> is preferably <NUM> or less. The nebulizer <NUM> may be provided in plurality.

The vacuum cap <NUM> is detachably installed on the upper portion of the nebulizer <NUM>. The vacuum cap <NUM> is installed to the nebulizer <NUM> to have a coupling force to the extent of being installed or detached by a person's hand. More particularly, a force applied for coupling or detaching the vacuum cap <NUM> and the nebulizer <NUM> is preferably 20N to 100N.

The vacuum cap <NUM> is connected to the distributor <NUM> to be described later with a hose. An O-ring <NUM> is connected to the vacuum cap <NUM>. The O-ring <NUM> is installed at a contact portion of the vacuum cap <NUM> and the nebulizer <NUM>, preventing a gap between the vacuum cap <NUM> and the nebulizer <NUM>.

The distributor <NUM> is connected to the vacuum cap <NUM> through a hose. The distributor <NUM> evenly distributes an air pressure of the negative pressure generated in the vacuum generating module <NUM> to be described later, performing a role to act this on each of the nebulizers <NUM>. The distributor <NUM> may adopt a known structure. An air pressure output from the vacuum generating module <NUM> is preferably - <NUM>. 5KPa to 0KPa. When an output air pressure of the vacuum generating module <NUM> is less than -<NUM>. 5KPa, there is a problem that the biomaterial <NUM> accommodated in the nebulizer <NUM> may flow backwards toward the distributor <NUM>. When an output air pressure of the vacuum generating module <NUM> is more than 0KPa, there is a problem that the biomaterial <NUM> accommodated in the nebulizer <NUM> cannot be prevented from leaking downwards.

The vacuum generating module <NUM> is connected to the distributor <NUM> with a hose. The vacuum generating module <NUM> is a device that generates an air pressure lower than atmospheric pressure in a specific branch pipe using the principal of the sprayer. The vacuum generating module <NUM> may be configured by employing a known vacuum generating module. The vacuum generating module <NUM> is electrically connected to the controller <NUM> to be described later, allowing variably adjusting a pressure generated by a signal of the controller <NUM>.

The compressor <NUM> is a device for acting an air pressure on the vacuum generating module <NUM>. As the air pressure generated in the compressor <NUM> is discharged to the outside through the vacuum generating module <NUM>, an air pressure lower than atmospheric pressure is formed in a specific portion of the vacuum generating module <NUM>.

A moisture removal filter (not illustrated) is installed between the vacuum cap <NUM> and the distributor <NUM> or between the distributor <NUM> and the vacuum generating module <NUM>. When a pressure generated in the vacuum generating module <NUM> exceeds an appropriate range and a greater negative pressure than necessary for the biomaterial <NUM> is generated, the biomaterial <NUM> may flow backwards from the nebulizer <NUM> toward the vacuum generating module <NUM>. In this case, the moisture removal filter performs a role to prevent the vacuum generating module <NUM> from being damaged by the back flowed biomaterial <NUM>.

The controller <NUM> is electrically connected to the vacuum generating module <NUM> and the nebulizer <NUM>. The controller <NUM> controls an output pressure of the vacuum generating module <NUM>. Further, the controller <NUM> controls the operation of the nebulizer <NUM>.

The drying fan <NUM> is arranged in the vicinity of the biomaterial <NUM> sprayed onto the substrate. The drying fan <NUM> is a device for blowing air to promote drying of the biomaterial <NUM> sprayed onto the substrate. The drying fan <NUM> may be controlled by the controller <NUM>. The drying fan <NUM> is preferably installed to the nebulizer cartridge <NUM>. An axial fan or a sirocco fan may be adopted as the drying fan <NUM>. The drying fan <NUM> is configured to suck air from a lateral direction of the nebulizer <NUM> and to discharge it to a downward direction of the nebulizer <NUM>.

The effect of the leaking prevention system for a downward spraying-type nebulizer for stacking a biomaterial of a bio-3D printer including the above-described components will be described in detail according to the operation sequence of the nebulizer.

Firstly, the nebulizer <NUM> is filled with the biomaterial <NUM>, and then the upper portion thereof is sealed with a vacuum cap <NUM>. The vacuum cap <NUM> is connected to the distributor <NUM> with a hose. Further, the distributor <NUM> is connected to the vacuum generating module <NUM> with another hose. The compressor <NUM> and the vacuum generating module <NUM> are connected by a hose.

In this state, the nebulizer <NUM> is operated by a signal of the controller <NUM>. As the vibrating membrane <NUM> of the nebulizer <NUM> vibrates at a high frequency, the biomaterial <NUM> is sprayed to the downward direction of the nebulizer <NUM>. After maintaining such a spraying for a predetermined time, the nebulizer <NUM> is stopped. The compressor <NUM> is always operated at the same time of turning the bio-3D printer on, regardless the operation of the nebulizer <NUM>. Accordingly, an air pressure lower than atmospheric pressure is generated in the vacuum generating module <NUM>, and a pressure below atmospheric pressure within a certain range acts on each of the nebulizers <NUM> through the distributor <NUM>. The biomaterial <NUM> accommodated in the nebulizer <NUM> may leak to the downward direction of the nebulizer <NUM> through a pore of the vibrating membrane <NUM> by gravity even when the vibrating membrane <NUM> does not vibrate. However, the biomaterial <NUM> accommodated in the nebulizer <NUM> does not leak from the nebulizer <NUM> by a pressure below atmospheric pressure generated in the vacuum generating module <NUM>.

When the nebulizer <NUM> is operated again by the controller <NUM>, the nebulizer <NUM> performs a normal output operation of the biomaterial <NUM> by vibration of the vibrating membrane <NUM>.

As described above, the leakage prevention for a downward spraying-type for stacking a biomaterial of a bio-3D printer according to the present disclosure is configured to apply an air pressure below atmospheric pressure within a preset range to the nebulizer, providing a prevention effect of leakage of biomaterial due to gravity during a time when the nebulizer is not operated.

In order to achieve the object as mentioned above, provided is a bio-3D printer comprising an output unit constituted by a leaking prevention system for a downward spraying-type nebulizer for stacking a biomaterial of the bio-3D printer according to the present disclosure, wherein the system constituting an output unit of the bio-3D printer includes:.

An air pressure output from the vacuum generating module is preferably -<NUM>. 5KPa to 0KPa.

The vacuum cap preferably has an O-ring at a portion in contact with the nebulizer.

Claim 1:
A bio-3D printer comprising an output unit constituted by a leakage prevention system for a downward spraying-type nebulizer for stacking a biomaterial of the bio-3D printer, characterized in that
the leakage prevention system comprises:
a nebulizer (<NUM>) that downwardly sprays a biomaterial (<NUM>) into a form of mist toward a substrate, the nebulizer (<NUM>) including a space accommodating the biomaterial (<NUM>) at an upper portion thereof, and having a vibrating membrane (<NUM>) installed at a lower portion thereof;
a vacuum cap (<NUM>) that is detachably installed on a upper portion of the nebulizer (<NUM>);
a distributor (<NUM>) that is connected to the vacuum cap (<NUM>) with a hose;
a vacuum generating module (<NUM>) that is connected to the distributor (<NUM>) with a hose;
a compressor (<NUM>) that generates an air pressure in the vacuum generating module (<NUM>);
a controller (<NUM>) that is electrically connected to the vacuum generating module (<NUM>) and the nebulizer (<NUM>), controlling an output pressure of the vacuum generating module (<NUM>) and an operation of the nebulizer (<NUM>), wherein the vibrating membrane (<NUM>) of the nebulizer (<NUM>) vibrates at a high frequency in response to a signal of the controller (<NUM>) so that the biomaterial (<NUM>) accommodated in the nebulizer (<NUM>) is divided into a mist form and sprayed downwards; and
a moisture removal filter installed between the vacuum cap (<NUM>) and the distributor (<NUM>) or between the distributor (<NUM>) and the vacuum generating module (<NUM>) for preventing the vacuum generating module (<NUM>) from being damaged by back flowed biomaterial (<NUM>).