CN117621439A - Pneumatic in-situ repair biological 3D printing gun, printing equipment and control method - Google Patents

Abstract

The invention relates to biological 3D printing equipment, in particular to a pneumatic in-situ repair biological 3D printing gun, printing equipment and a control method, wherein the printing equipment comprises a base and a printing gun head which are connected in a hinged manner; the inside of the printing gun head is provided with a needle cylinder groove, a heat exchange component, a microcontroller and a sensor; the front end of the needle cylinder groove is provided with a printing port penetrating through the printing gun head, the needle cylinder is arranged in the needle cylinder groove, and the front end of the needle cylinder extends into the printing port; the heat exchange component is embedded in the printing gun head; the sensor comprises an air pressure sensor and a temperature sensor which are respectively attached to the inner wall of the needle cylinder groove; the microcontroller is electrically connected with the heat exchange assembly and the sensor; a piston is arranged in the base, one end of the piston is connected with external air supply equipment through an air inlet channel arranged in the base, and the other end of the piston is connected into the needle cylinder groove. Compared with the prior art, the invention solves the defects of biological 3D printing in the aspects of printing speed and standardization in the prior art, and realizes standardized and automatic control of the printing quantity, printing speed and printing precision of the printing gun.

Description

Pneumatic in-situ repair biological 3D printing gun, printing equipment and control method

Technical Field

The invention relates to biological 3D printing equipment, in particular to a pneumatic in-situ repair biological 3D printing gun, printing equipment and a control method.

Background

Biological 3D printing technology is an innovative manufacturing technology that utilizes biological materials such as cells, bio-gels, etc. to construct organisms with complex structures and functions. The technology realizes high-precision three-dimensional printing by depositing biological materials layer by layer and using computer-controlled precise movement. Biological 3D printing technology has great potential in the biomedical field, and can be used for repair and regeneration of organs and tissues, manufacture of customized medical devices, and development of drug delivery systems. It also provides a platform for researchers to simulate and study organisms, accelerating the development of bioscience. However, biological 3D printing techniques still face challenges such as issues of biomaterial selection, printing speed, and feasibility, requiring further research and improvement.

When it comes to automated applications of in situ biological 3D technology, there are not so many detailed cases and examples available for reference. Some research institutions and academia are exploring the automation potential of in situ biological 3D technology. The goal of these studies is to develop a system capable of automatically performing a bioprinting task to improve the efficiency and accuracy of bioprinting and to reduce the need for manual operations.

In the existing biological 3D printing technology, the following defects and problems are often associated:

1) Printing speed and mass production: biological 3D printing is often a time consuming process, especially for large scale or complex constructs. Current printing speeds are slow, limiting the range of applications of biological 3D printing techniques, especially in situations where mass production is required.

2) Structure and resolution limitations: biological 3D printing techniques remain a challenge in achieving fine structures and high resolution. The current printing resolution is limited, and tiny structures and details are difficult to realize, so that the application of the printing resolution in certain application fields is limited.

3) Lack of standardization and specification: due to the rapid development of biological 3D printing technology, there is a lack of unified standards and specifications, leading to variability between different laboratories and manufacturers. This makes the reproducibility and comparability of the results difficult and limits further application and commercialization of the technology.

In view of the above drawbacks, there is a need to develop an apparatus and control method for automated, standardized biological 3D printing to better meet the needs of biological 3D printing.

Disclosure of Invention

The invention aims to solve at least one of the problems and provide a pneumatic in-situ repair biological 3D printing gun, printing equipment and a control method, so as to solve the defects of biological 3D printing in printing speed and standardization in the prior art.

The aim of the invention is achieved by the following technical scheme:

the first aspect of the invention discloses a pneumatic in-situ repair biological 3D printing gun, which comprises a base and a printing gun head which are connected in a hinged manner;

the printing gun head is internally provided with a needle cylinder groove, a heat exchange assembly, a microcontroller and a sensor;

the front end of the needle cylinder groove is provided with a printing port penetrating through the printing gun head, the needle cylinder loaded with printing ink is arranged in the needle cylinder groove, and the front end of the needle cylinder extends into the printing port;

the heat exchange component is embedded in the printing gun head and used for controlling the temperature in the needle cylinder groove;

the sensor comprises an air pressure sensor and a temperature sensor which are respectively attached to the inner wall of the needle cylinder groove;

the microcontroller is electrically connected with the heat exchange assembly and the sensor;

the base in be equipped with the piston, the one end of piston links to each other with outside air feed equipment through seting up in the air inlet channel in the base, the other end is connected to in the cylinder groove.

Preferably, the base is connected with the printing gun head through a movable hinge.

Preferably, the printing gun further comprises buckles respectively arranged on the base and the printing gun head, and the base is locked with the printing gun head through clamping connection of the buckles on the base and the printing gun head.

When the material in the printing gun needs to be replaced, the user only needs to open the printing gun head and put the needle cylinder filled with new ink into the printing gun head, and the whole process is very convenient.

Preferably, the heat exchange assembly comprises a semiconductor refrigeration sheet and a liquid cooling circulation system;

one side surface of the semiconductor refrigerating sheet is attached to the needle cylinder groove, and the other side surface is attached to the liquid cooling circulation system;

the liquid cooling circulation system is connected with external heat exchange equipment.

Preferably, the liquid cooling circulation system is a lamellar water cooling radiator and is connected with external heat exchange equipment.

Preferably, the air supply device comprises an air pump and a control valve, the air pump is connected to the piston through an air pipe, and the control valve is arranged on the air pipe.

Preferably, the control valve is a proportional valve.

The air pump, the proportional valve and the piston are connected in sequence through an air pipe.

A second aspect of the invention discloses a printing apparatus comprising a robotic arm, a control system and a print gun as described above;

the printing gun is connected to the tail end of the mechanical arm;

the control system is electrically connected with the microcontroller, the mechanical arm and the air supply equipment.

The main function of the mechanical arm is to replace a manual handheld printing gun to carry out in-situ biological printing work on a damaged part, and the control program of the mechanical arm can be remotely carried out on a computer and comprises the setting of key parameters such as moving speed, printing path and the like.

In 3D printing, the mechanical arm is used as a displacement control device of a printing head (printing gun), so that accurate spraying and deposition of highly controllable materials can be realized, and printing precision and quality are ensured. It can be accurately moved and positioned in three dimensions so that complex geometries and details can be created during printing. Applications of robotic arms in 3D printing techniques may include bioprinting, manufacturing prototypes, custom parts, and the like. For example, in bioprinting, robotic arms may assist in depositing biological material precisely to specific locations for tissue engineering and organ regeneration. In the manufacture of prototype and custom parts, the robotic arm can assist in printing complex structures and shapes, speeding up the product development and manufacturing process.

Preferably, the base of the printing gun is connected to the tail end of the mechanical arm through a flange plate.

Preferably, the mechanical arm is a six-axis mechanical arm. The six-axis mechanical arm is applied to the 3D printing technology to realize high-precision printing and construction of a complex structure, and the motion of the mechanical arm has multiple degrees of freedom and can perform normal printing under the condition of complex positions.

A third aspect of the present invention discloses a method of controlling a printing apparatus as described in any one of the above, comprising the steps of:

s1: the control system acquires temperature data in the syringe groove and compares the temperature data with set parameters:

a) If the temperature measurement data is within the set range, the microcontroller instructs the operation of the heat exchange assembly to control the temperature of the needle cylinder groove, and then the step S2 is carried out;

b) If the temperature measurement data is out of the set range, the microcontroller instructs the operation of the heat exchange assembly to regulate the temperature of the needle cylinder groove, and the step S2 is carried out after the measurement data is stabilized in the set range;

s2: the control system obtains an operation setting program of the mechanical arm:

a) If the acquisition is successful, entering a step S3;

b) If the acquisition fails, stopping the program and waiting for the program input, and entering step S3 after the input is completed;

s3: the control system instructs the air supply equipment to operate, and acquires pressure data in the syringe groove and compares the pressure data with set parameters:

a) If the pressure measurement data is within the set range, the control system instructs the air supply equipment to control the pressure of the needle cylinder groove, and then printing is started;

b) If the pressure measurement data is out of the set range, the control system instructs the air supply device to regulate the pressure of the needle cylinder groove, and printing is started after the measurement data is stabilized within the set range.

Preferably, the operation setting program of the mechanical arm comprises path planning, moving speed and residence time of the mechanical arm.

Compared with the prior art, the invention has the following beneficial effects:

the invention combines biological 3D printing with the mechanical arm and the remote operation automation system, thereby being capable of controlling the printing amount of the biological ink of the printing gun in a standardized way, and being convenient for repairing the damaged part in situ more accurately. Further analysis has the specific advantages as follows:

1. and (5) automatic control. In the field of automation control, a mechanical arm is used to connect the tail end of a printing gun, and printing can be automatically performed on a damaged part according to a pre-planned path based on a control system and the mechanical arm. In the automatic process, the control system accurately controls key parameters such as printing speed, path and the like, and ensures efficient and accurate execution through the mechanical arm.

2. And 3, accurate temperature control. To ensure the reactivity of the bio-ink before printing and after spraying, the temperature of the printed material must be maintained in the range of 0-10 ℃. In the invention, a set of temperature control system is adopted, and the core of the system is a microcontroller matched with a temperature sensor, a semiconductor refrigerating sheet and a liquid cooling circulation system. In the cylinder slot of the printing gun, a temperature sensor is installed, and the outer wall is embedded with a bidirectional refrigerating sheet and a sheet-shaped liquid cooling circulation system. The integrated application of the designs can effectively control and maintain the required temperature conditions and ensure the quality and activity of the biological ink.

3. The user customizes the output. In a control system (computer application program) matched with the printing gun and the UR5 mechanical arm, a user has the functions of autonomously setting temperature, air pressure value, printing running track and glue output. The control system has a bidirectional communication function, can not only receive required printing parameters input by a user, but also monitor printing progress in real time and adjust temperature, pressure value and printing path, thereby improving controllability and visualization of the whole system. In addition, the user can select proper materials by independently replacing the ink of the printing gun, so that more personalized requirements are met. Through the intelligent control, a user can flexibly adjust a plurality of parameters so as to achieve the aim of optimizing the printing effect. Meanwhile, the real-time progress monitoring and adjustable parameter setting ensure the high controllability and flexibility of the printing process, thereby meeting the requirements in various different application scenes.

4. And the cost is high. The whole design and the material of the printing gun are manufactured independently, namely, the printing gun head and the base are opened in a rotatable mode, the printing gun can be further manufactured into a detachable structure, and the printing gun can be matched with other parts for use, so that the printing gun is wide in practicability and high in practicality and cost performance. In addition, the printing gun part adopts air pressure to supply energy, and the realization method is realized by connecting an air pump and an air pressure proportional valve, namely pneumatic output. Compared with the traditional electric or fuel driving equipment, the energy can be utilized more efficiently, the energy consumption and emission are reduced, and the environment is more friendly and safer. In addition, because the air pump components are relatively fewer, maintenance is simpler, and meanwhile, the maintenance cost is reduced. Meanwhile, the output of the air pump is easy to adjust and quick in response, so that the air pump is suitable for different working requirements, and extremely high flexibility and reliability are shown.

5. The biological 3D printing gun has the remarkable characteristics of light weight, easiness in production and the like. Compared with the existing manual operation mode, the printing gun can effectively solve the problem that the traditional method is difficult in terms of guaranteeing printing quality and is not suitable for different injured parts of a human body due to overlarge equipment size. The printing gun only needs to provide the function of containing ink and installing the related controller, the whole size can be greatly reduced, the optimized printing gun is about 136.00mm long and 36.3mm wide, and the volume is small, so that the printing gun can be conveniently installed at the tail end of the mechanical arm, realizes automatic control and is used for accurate repair.

Drawings

FIG. 1 is a schematic cross-sectional view of a print gun;

FIG. 2 is a schematic view of the structure of the print gun when open;

FIG. 3 is a schematic diagram of a water-cooled circulation structure of a print gun;

FIG. 4 is a schematic diagram of the overall structure of the bit printing apparatus;

FIG. 5 is a control flow diagram of a printing apparatus;

in the figure: 1-a print gun head; 2-an air pressure sensor; 3-a liquid cooling circulation system; 4-a microcontroller; 5-semiconductor refrigerating sheets; 6-a piston; 7-a base; 8-a living hinge; 9-a temperature sensor; 10-needle cylinder grooves; 11-a mechanical arm; 12-a flange plate; 13-a print gun; 14-a control valve; 15-trachea; 16-air pump.

Detailed Description

The invention will now be described in detail with reference to the drawings and specific examples.

Examples

A pneumatic in-situ repair biological 3D printing gun 13, as shown in figures 1-5, comprises a base 7 and a printing gun head 1 which are connected in a hinged manner;

the printing gun head 1 is internally provided with a needle cylinder groove 10, a heat exchange component, a microcontroller 4 and a sensor;

the front end of the needle cylinder groove 10 is provided with a printing port penetrating through the printing gun head 1, the needle cylinder loaded with printing ink is arranged in the needle cylinder groove 10, and the front end of the needle cylinder extends into the printing port;

the heat exchange component is embedded in the printing gun head 1 and is used for controlling the temperature in the needle cylinder groove 10;

the sensor comprises an air pressure sensor 2 and a temperature sensor 9 which are respectively attached to the inner wall of the needle cylinder groove 10;

the microcontroller 4 is electrically connected with the heat exchange component and the sensor;

the base 7 is internally provided with a piston 6, one end of the piston 6 is connected with external air supply equipment through an air inlet channel arranged in the base 7, and the other end is connected into the needle cylinder groove 10.

More specifically, in the present embodiment:

the print gun 13 is formed by hinging a base 7 with the print gun head 1, as shown in figures 1, 2 and 3.

The inside of the printing gun head 1 is provided with a needle cylinder groove 10 for placing a needle cylinder containing printing ink, the front end of the needle cylinder groove 10 is provided with a printing opening penetrating through the printing gun head 1, and the front end of the needle cylinder extends into the printing opening during assembly, so that the ink can flow out from the printing opening. The printing gun head 1 is internally provided with a microcontroller 4, a heat exchange component for regulating and controlling the temperature in the syringe tank 10 and a power supply for supplying power, the inner wall surface of the syringe tank 10 is also provided with an air pressure sensor 2 and a temperature sensor 9, and the air pressure sensor 2, the temperature sensor 9 and the heat exchange component are respectively electrically connected with the microcontroller 4 and the power supply. In this embodiment, the microcontroller 4 is of STM32F103C8T6 type, the temperature sensor is of DS18B20 type, and the air pressure sensor is of SMC air pressure sensor. As shown in fig. 3, the heat exchange assembly specifically comprises a semiconductor refrigeration sheet 5 with one side surface attached to the wall surface of the syringe tank 10 and a liquid cooling circulation system 3 attached to the other side surface of the semiconductor refrigeration sheet 5, wherein the liquid cooling circulation system 3 is further connected with external heat exchange equipment; the semiconductor refrigerating sheet 5 adopts bidirectional refrigeration, and the liquid cooling circulation system 3 adopts a lamellar water-cooling radiator. At the part provided with the heat exchange component, the printing gun head 1 can be divided into a main body part provided with a needle cylinder groove 10 and a cover plate covered with the sealing heat exchange component, and the main body part and the cover plate can be detachably connected, such as screw fixation, clamping fixation and the like, a pair of openings for allowing a conduit for circulating heat exchange liquid to pass through are reserved on the cover plate, and the openings are respectively positioned at two ends of the liquid cooling circulation system 3.

A piston 6 is arranged in the base 7, one end of the piston 6 is communicated with an air inlet channel arranged in the base 7, the other end of the piston is communicated with a needle cylinder groove 10, and the air inlet channel is further connected with external air supply equipment. The air pressure of the air supply device can be transmitted into the cylinder groove 10 through the piston 6. The air supply device is mainly an air pump 16, the air pump 16 is connected with one end of the piston 6 through an air inlet channel by an air pipe 15, and a control valve 14 is arranged on the air pipe 15. The control valve 14 is preferably a proportional valve in this embodiment.

The base 7 and the printing gun head 1 are hinged by adopting a movable hinge 8, so that the printing gun head 1 can rotate around a hinge point to be opened, as shown in fig. 2, and the needle cylinder in the needle cylinder groove 10 can be replaced to replace printing ink. Based on the requirement of rotation opening, the printing gun head 1 adopts an ellipsoidal structure so as to avoid structural collision; meanwhile, the printing gun head 1 with the ellipsoidal structure can be better adapted to the shape of the used needle cylinder. Further, since the print gun 13 is pneumatically driven, at each junction, such as: sealing rings are arranged between the base 7 and the piston 6, between the piston 6 and the printing gun head 1, between the front end of the syringe and the syringe groove 10, and the like, so as to avoid leakage. A buckle is further arranged in the base 7 and the printing gun head 1 and used for limiting and locking after being rotationally closed, so that loosening in the operation process is avoided. The button extending out of the printing gun head 1 is attached to the side face of the buckle and used for releasing the clamping state, so that the printing gun head 1 and the base 7 can rotate around the movable hinge 8.

The print gun 13 has a very small overall size, and is measured to be about 136.00mm long and 36.3mm wide, so that the print gun can be suitable for various injured parts with high environmental requirements.

The print gun 13 is used in combination with the mechanical arm 11, as shown in fig. 4, specifically, the base 7 of the print gun 13 is connected to the end of the mechanical arm 11 through the flange 12, and the print gun 13 moves through the movement of the mechanical arm 11. The mechanical arm 11 in this embodiment adopts a UR5 six-axis mechanical arm 11, which has 6 degrees of freedom and flexible movement capability. The main function of the mechanical arm 11 is to replace manual hand-held printing gun 13 to perform in-situ biological printing on the damaged part, and automatic control can be realized by inputting a program of a control system to perform automatic control, wherein the controlled parameters comprise the selection of moving speed and the setting of a printing path.

The control system in this embodiment adopts a computer with a display, and is electrically connected with the mechanical arm 11, the air pump 16, the proportional valve and the microcontroller 4. The user can directly input the required temperature value (DEG C), air pressure value (MPa) and printing path in the control system, and can also set related parameters of the mechanical arm 11, such as the moving speed (mm/s) of the mechanical arm 11, the needle size (mm) and the like. After the selection is completed and confirmed, the control system sends instructions to the print gun 13 and the mechanical arm 11 to fulfill the requirements of the user.

In order to further accelerate the curing of the 3D printing material, an ultraviolet lamp is arranged at the front end of the housing and beside the printing port, and is electrically connected with the microcontroller 4, and the ultraviolet lamp is controlled to be turned on and off during the 3D printing so as to accelerate the completion of printing and curing.

The control logic proceeds according to the following method, as shown in fig. 5:

s1: the control system obtains temperature data in the syringe tank 10 and compares it with set parameters:

a) If the temperature measurement data is within the set range, the microcontroller 4 instructs the heat exchange assembly to operate to control the temperature of the syringe tank 10, and then step S2 is performed;

b) If the temperature measurement data is outside the set range, the microcontroller 4 instructs the heat exchange assembly to operate to regulate the temperature of the syringe tank 10, and the step S2 is performed after the measurement data is stabilized within the set range;

s2: the control system acquires an operation setting program of the robot arm 11:

a) If the acquisition is successful, entering a step S3;

b) If the acquisition fails, stopping the program and waiting for the program input, and entering step S3 after the input is completed;

s3: the control system instructs the air supply device to operate and acquires pressure data in the syringe tank 10 to compare with the set parameters:

a) If the pressure measurement data is within the set range, the control system instructs the air supply device to control the pressure of the syringe tank 10, and then printing is started;

b) If the pressure measurement data is outside the set range, the control system instructs the air supply device to regulate the pressure of the syringe tank 10, and printing is started after the measurement data is stabilized within the set range.

The operation setting program of the mechanical arm 11 includes parameters such as path planning, moving speed, and residence time of the mechanical arm 11.

In addition, an alarm can be further arranged on the mechanical arm 11 and electrically connected with the control system, and when errors occur continuously in the steps or the set range cannot be reached for a long time, an alarm is sent out to remind a user of whether the parameter setting has a problem or whether the equipment needs maintenance.

When in use, the utility model is characterized in that:

1. one side of the flange plate 12 is firstly arranged on an end effector of the mechanical arm 11, and then the tail end of the printing gun 13 is nested at the other end of the flange plate 12, so that the combination of the printing gun head 1 and the mechanical arm 11 is realized.

2. By means of the movable hinge 8 design of the printing gun 13, the buckle of the printing gun head 1 is unlocked, the printing gun head 1 is rotated to expose the syringe groove 10, a syringe (10 mL) filled with printing ink is placed into the syringe groove 10, and the syringe groove is carefully inspected, and sealing is carried out after confirming that the syringe is correct.

3. The power supply, control system of the print gun head 1 and the air pump 16 are turned on. It is observed whether the value on the pneumatic proportional valve is 0, and if not, the air pump 16 and control system are adjusted to zero. The preparation of the print gun 13 in advance is completed.

4. A constant temperature environment (0-10 c) needs to be created before the print gun 13 and the robotic arm 11 can operate. After the power supply is started, a user inputs temperature parameters required by the biological ink on the computer, and the microcontroller 4 receives signals to control the semiconductor refrigerating sheet 5 to start cooling the needle cylinder filled with the printing ink, so that the temperature of the needle cylinder is reduced to a set fluid and activation temperature, and the quality and activity of the biological ink are ensured; simultaneously, the liquid cooling circulation system 3 also synchronously starts to operate so as to radiate heat for the other side of the semiconductor refrigerating sheet 5. The real-time and continuous temperature change in the cooling process is collected by the temperature sensor 9 and fed back to the display in real time in a curve continuous change mode, so that data visualization is realized, and the user can observe, compare and debug conveniently.

5. And (3) turning on a power switch of the mechanical arm 11, and after the initialization is completed, the control system instructs the mechanical arm 11 to automatically move to a set initial point. The user enters the path that he wants to print and the associated print parameters into the control system, awaiting start-up.

6. After the air pressure is set in the control system, the print gun 13 and air tube 15 are connected by the piston 6 of the syringe base 7. The air pressure sensor 2 on the inner wall of the needle cylinder can transmit real-time air pressure data to the microcontroller 4, the display displays the current air pressure value in real time, the air pump 16 starts to operate, air pressure is transmitted to the proportional valve and the printing gun 13 from the air pipe 15, and printing is started. When the mechanical arm 11 finishes printing according to the path, the control system instructs the air pump 16 to stop air supply, the air pressure is stopped immediately, and the ink is stopped from the needle cylinder.

The invention provides an advanced version of an automated biological 3D printing gun 13 by adopting a mechanical arm 11 and a remote computer control program. The biological 3D printing gun 13 is repaired in situ by pneumatic force based on the control of the mechanical arm 11, so that in-vivo damaged tissues are repaired in situ, and the whole printing process is quickened and quantified by controlling the printing gun 13 through the mechanical arm 11. The computer application connects the print gun 13 and the robotic arm 11 so that the user's criteria can be met, increasing their commercial value. To better meet the demands of 3D bioprinting.

The previous description of the embodiments is provided to facilitate a person of ordinary skill in the art in order to make and use the present invention. It will be apparent to those skilled in the art that various modifications can be readily made to these embodiments and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above-described embodiments, and those skilled in the art, based on the present disclosure, should make improvements and modifications without departing from the scope of the present invention.

Claims (10)

1. The pneumatic in-situ repairing biological 3D printing gun is characterized by comprising a base (7) and a printing gun head (1) which are connected in a hinged manner;

the inside of the printing gun head (1) is provided with a needle cylinder groove (10), a heat exchange component, a microcontroller (4) and a sensor;

the front end of the needle cylinder groove (10) is provided with a printing port penetrating through the printing gun head (1), the needle cylinder loaded with printing ink is arranged in the needle cylinder groove (10), and the front end of the needle cylinder extends into the printing port;

the heat exchange component is embedded in the printing gun head (1) and is used for controlling the temperature in the needle cylinder groove (10);

the sensor comprises an air pressure sensor (2) and a temperature sensor (9) which are respectively attached to the inner wall of the needle cylinder groove (10);

the microcontroller (4) is electrically connected with the heat exchange component and the sensor;

the base (7) is internally provided with a piston (6), one end of the piston (6) is connected with external air supply equipment through an air inlet channel arranged in the base (7), and the other end of the piston is connected into the needle cylinder groove (10).

2. A pneumatic in-situ repair bio-3D printing gun according to claim 1, characterized in that the printing gun (13) further comprises a buckle arranged on the base (7) and the printing gun head (1) respectively, and the buckle on the base (7) is clamped with the buckle on the printing gun head (1) to lock the base (7) and the printing gun head (1).

3. The pneumatic in-situ repair biological 3D printing gun according to claim 1, wherein the heat exchange assembly comprises a semiconductor refrigeration sheet (5) and a liquid cooling circulation system (3);

one side surface of the semiconductor refrigerating sheet (5) is attached to the needle cylinder groove (10), and the other side surface is attached to the liquid cooling circulation system (3);

the liquid cooling circulation system (3) is connected with external heat exchange equipment.

4. A pneumatic in situ remediation bio-3D printing gun according to claim 1 wherein the air supply means comprises an air pump (16) and a control valve (14), the air pump (16) being connected to the piston (6) by an air tube (15), the control valve (14) being arranged on the air tube (15).

5. A pneumatic in situ remediation bio-3D printing gun according to claim 4 wherein the control valve (14) is a proportional valve.

6. Printing apparatus, characterized by comprising a robotic arm (11), a control system and a print gun (13) according to any of claims 1-5;

the printing gun (13) is connected to the tail end of the mechanical arm (11);

the control system is electrically connected with the microcontroller, the mechanical arm (11) and the air supply equipment.

7. A printing apparatus according to claim 6, wherein the base (7) of the print gun (13) is connected to the end of the arm (11) by means of a flange (12).

8. A printing apparatus according to claim 6, wherein the robot arm (11) is a six-axis robot arm.

9. A method of controlling a printing apparatus according to any one of claims 6 to 8, comprising the steps of:

s1: the control system acquires temperature data in the syringe tank (10) and compares the temperature data with set parameters:

a) If the temperature measurement data is in the set range, the microcontroller (4) instructs the operation of the heat exchange assembly to control the temperature of the needle cylinder groove (10), and then the step S2 is carried out;

b) If the temperature measurement data is out of the set range, the microcontroller (4) instructs the operation of the heat exchange assembly to regulate the temperature of the needle cylinder groove (10), and the step S2 is carried out after the measurement data is stabilized in the set range;

s2: the control system acquires an operation setting program of the mechanical arm (11):

a) If the acquisition is successful, entering a step S3;

b) If the acquisition fails, stopping the program and waiting for the program input, and entering step S3 after the input is completed;

s3: the control system instructs the air supply device to operate, and acquires pressure data in the syringe tank (10) and compares the pressure data with set parameters:

a) If the pressure measurement data is within the set range, the control system instructs the air supply equipment to control the pressure of the needle cylinder groove (10), and then printing is started;

b) If the pressure measurement data is outside the set range, the control system instructs the air supply device to regulate the pressure of the syringe groove (10), and printing is started after the measurement data is stabilized within the set range.

10. A control method according to claim 9, characterized in that the operation setting program of the robot arm (11) comprises path planning, movement speed and dwell time of the robot arm (11).