Method and system for regulating and controlling temperature of high-temperature printing nozzle for multi-material biological 3D printing

Abstract

According to the temperature regulation and control method and system for the multi-material biological 3D printing high-temperature printing nozzle, a thermal imaging image of a target area of the nozzle is obtained in real time through a thermal imager, and the temperature value of an area of interest, especially the temperature of a contact area of a high-temperature molten material and hydrogel, is accurately extracted through a U-net image segmentation algorithm. The extracted temperature data are transmitted to the controller through serial port communication, the controller adjusts the fan power through a PID control algorithm or a threshold value control algorithm according to the temperature value or the difference value between the temperature and the set target temperature, and accurate regulation and control over the temperature of the printing spray head are achieved. The system has the advantages of being high in precision, high in real-time performance, high in adaptability and the like, the influence of temperature fluctuation on cell activity can be effectively avoided, and the biological activity of the hydrogel composite scaffold in the multi-material biological 3D printing process is ensured. The method is particularly suitable for 3D printing of degradable material-hydrogel composite scaffolds, and has important practical application value.

Description

Technical Field

[0001] The present invention relates to biological 3D printing technology, and in particular to a temperature control method and system for a high-temperature printing nozzle for multi-material biological 3D printing. Background Art

[0002] In the complex structure printing in the field of multi-material biological 3D printing, high-temperature molten materials will cause burns to hydrogel cells during the molding process, affecting cell activity, causing the overall structure biological activity to decrease, greatly affecting the subsequent production effect of the finished product. In the process of biological 3D printing, temperature control is very important. Traditional temperature control systems usually rely on fixed temperature sensors and simple switch control methods, but these methods usually cannot provide high-precision and real-time temperature control effects. In complex multi-material printing scenarios, it is difficult for existing temperature control systems to achieve accurate temperature monitoring and regulation of the contact area between high-temperature molten materials and hydrogels, resulting in large temperature fluctuations and unable to effectively avoid damage to hydrogel cells. Although thermal imaging technology can detect temperature changes in different areas, the existing technology has not yet effectively combined thermal imaging technology with intelligent control solutions to achieve real-time and accurate regulation of the temperature of multi-material biological 3D printing nozzles, especially in the printing scenario of high-temperature molten materials and hydrogel composite scaffolds. There is still a technical gap. Therefore, the development of a method and system that can monitor and accurately adjust the temperature in real time is of great significance for improving the quality and biological activity of multi-material biological 3D printing products.

[0003] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0004] The main purpose of the present invention is to overcome the defects existing in the above-mentioned background technology and provide a method and system for controlling the temperature of a high-temperature printing nozzle for multi-material biological 3D printing.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for controlling temperature of a high-temperature printing nozzle for multi-material biological 3D printing, comprising the following steps:

[0007] S1: The thermal imager performs real-time thermal imaging of the target area of ​​the high-temperature printing nozzle of multi-material biological 3D printing. The computer communicates with the thermal imager to obtain the thermal imaging image of the target area of ​​the nozzle in real time, and accurately monitors the temperature distribution of the high-temperature molten material and the hydrogel composite scaffold;

[0008] S2: The thermal imaging image is processed using the U-net image segmentation algorithm to extract the temperature value of the area of ​​interest in the multi-material biological 3D printing nozzle, including the temperature of the contact area between the high-temperature molten material and the hydrogel;

[0009] S3: The extracted temperature data is transmitted to the control unit via serial communication, and the control unit receives the data and calculates the difference between the temperature and the set target temperature;

[0010] S4: According to the temperature value or temperature difference, the fan power is adjusted through a threshold control algorithm or a PID control algorithm to achieve precise regulation of the temperature of the multi-material biological 3D printing nozzle, so as to ensure that the high-temperature molten material will not damage the hydrogel cells during the molding process and maintain the biological activity of the overall structure.

[0011] Furthermore, step S1 specifically includes:

[0012] Acquire a thermal imaging image of the target area of ​​a high-temperature printing nozzle for multi-material 3D bioprinting in real time using a thermal imager;

[0013] The computer communicates with the thermal imager through the SDK interface of the thermal imager, and receives and stores the thermal imaging image data in real time.

[0014] Furthermore, step S2 specifically includes:

[0015] The U-net image segmentation algorithm is used to process the thermal imaging image and automatically segment the region of interest;

[0016] The temperature values ​​of the region of interest are extracted, especially the temperature of the region where the high temperature molten material contacts the hydrogel.

[0017] Furthermore, step S3 specifically includes:

[0018] The extracted temperature data is transmitted to the Arduino control unit via the serial communication protocol;

[0019] The Arduino control unit receives the temperature data and calculates the difference between the current temperature and the set target temperature.

[0020] Furthermore, step S4 specifically includes:

[0021] According to the temperature difference or temperature value, the fan power is calculated by a PID control algorithm or a threshold control algorithm;

[0022] By adjusting the fan speed through PWM signals, the temperature of the multi-material biological 3D printing nozzle can be precisely adjusted to ensure that the high-temperature molten material will not damage the hydrogel cells during the molding process and maintain the biological activity of the overall structure.

[0023] A multi-material biological 3D printing high-temperature printing nozzle temperature control system, comprising:

[0024] Thermal imager, used to obtain real-time thermal imaging images of the target area of ​​the high-temperature printing nozzle of multi-material biological 3D printing and detect temperature distribution;

[0025] A computer, communicating with the thermal imager, for receiving and processing thermal imaging image data and running an image segmentation algorithm to extract temperature values ​​of the region of interest;

[0026] The controller is connected to the computer through a serial communication port, and is used to receive temperature data transmitted by the computer, and calculate the fan power through a threshold control algorithm or a PID control algorithm according to the temperature value or the difference between the temperature and the set target temperature;

[0027] The fan is connected to the controller and is used to adjust the rotation speed according to the control signal output by the controller to achieve precise adjustment of the temperature of the multi-material biological 3D printing nozzle.

[0028] Furthermore, the thermal imager communicates with the computer via the SDK interface, acquires the thermal imaging image of the target area in real time, and detects the temperature distribution through the image data.

[0029] Furthermore, the computer runs a U-net image segmentation algorithm to automatically segment the thermal imaging image, extract the temperature value of the area of ​​interest, and avoid noise interference.

[0030] Furthermore, the controller is an Arduino controller, which receives temperature data transmitted by a computer through a serial communication protocol, and calculates the fan power through a PID control algorithm or a threshold control algorithm according to the temperature difference or the temperature value.

[0031] Furthermore, the fan is connected to the controller via a PWM signal, and the rotation speed is adjusted according to the PWM signal output by the controller to achieve precise adjustment of the temperature of the multi-material biological 3D printing nozzle.

[0032] The present invention has the following beneficial effects:

[0033] The present invention provides a multi-material biological 3D printing high-temperature printing nozzle temperature control method and system, through a thermal imager to obtain the temperature data of the multi-material biological 3D printing high-temperature printing nozzle in real time, the thermal imaging target area is located near the nozzle of the nozzle, the temperature value of the region of interest is accurately extracted by combining the U-net image segmentation algorithm, and the fan power is adjusted by the PID control or threshold control algorithm to achieve efficient and accurate temperature control. The system has high-precision temperature control capability, can effectively avoid noise interference, and ensure the accuracy of temperature data; strong real-time performance, can quickly adjust the ambient temperature according to the real-time temperature data, and ensure that the temperature is within the set range; strong adaptability, can automatically adjust the fan power according to different temperature changes, and adapt to a variety of temperature control requirements; at the same time, the system is simple and easy to use, through serial communication and a simple connection with a controller (such as Arduino), the user can easily set and adjust the temperature target value, and monitor the temperature data in real time. The system is particularly suitable for the printing of degradable material-hydrogel composite scaffolds in multi-material biological 3D printing, can effectively prevent the high-temperature molten material from scalding the hydrogel cells, maintain the biological activity of the overall structure, and has important practical application value.

[0034] The embodiments of the present invention have the following advantages:

[0035] 1. High-precision temperature control: Utilizing the high-precision temperature detection capability of the thermal imager and the U-net image segmentation algorithm, the present invention can achieve more accurate temperature data extraction and effectively avoid noise interference, thereby achieving more precise temperature control.

[0036] 2. Strong real-time performance: The system can obtain temperature data in real time and adjust the temperature according to the real-time data to ensure that the ambient temperature is within the set range.

[0037] 3. Strong adaptability: The system can automatically adjust the fan power according to different temperature changes to adapt to different temperature control requirements.

[0038] 4. Easy to use: Through simple connection with Arduino via serial communication, users can easily set and adjust temperature target values, as well as monitor temperature data.

[0039] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of a method for controlling temperature of a high-temperature printing nozzle for multi-material biological 3D printing according to an embodiment of the present invention.

[0041] Figure 2 This is a schematic structural diagram of a high-temperature printing nozzle temperature control system for multi-material biological 3D printing according to an embodiment of the present invention.

[0042] Figure 3 This is an example diagram of a computer acquiring a temperature image through a thermal imager and performing U-net image segmentation processing in an embodiment of the present invention.

[0043] Figure 4 This is an example diagram of using the U-net algorithm to segment an image and extract the temperature of an area of ​​interest in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0045] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing as well as for coupling or communication.

[0046] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] See also Figure 1 The embodiment of the present invention provides a method for controlling the temperature of a high-temperature printing nozzle for multi-material biological 3D printing, comprising the following steps:

[0049] Step S1, data acquisition: The thermal imager performs real-time thermal imaging of the target area of ​​the high-temperature printing nozzle of the multi-material biological 3D printing. The computer communicates with the thermal imager to obtain the thermal imaging image of the target area in real time, and accurately monitors the temperature distribution of the high-temperature molten material and the hydrogel composite scaffold. The target area is located near the nozzle of the nozzle and is a sensitive area for temperature changes during the printing process. The temperature control system of the nozzle monitors and adjusts the temperature of this area to ensure that the high-temperature molten material will not cause burns to the hydrogel cells during the molding process.

[0050] Step S2, image segmentation and temperature extraction: The thermal imaging image is processed using the U-net image segmentation algorithm to extract the temperature value of the area of ​​interest in the multi-material biological 3D printing nozzle, including the temperature of the contact area between the high-temperature molten material and the hydrogel, so as to avoid scalding the hydrogel cells;

[0051] Step S3, temperature transmission and processing: The extracted temperature data is transmitted to the control unit via serial communication, and the control unit receives the data and calculates the difference between the temperature and the set target temperature.

[0052] Step S4, real-time adjustment of fan power: According to the temperature value or temperature difference, the fan power is adjusted through a threshold control algorithm or a PID control algorithm to achieve precise adjustment of the temperature of the multi-material biological 3D printing nozzle, ensuring that the temperature is controlled within a range suitable for multi-material biological 3D printing, so that the high-temperature molten material will not damage the hydrogel cells during the molding process, and the biological activity of the overall structure is maintained.

[0053] In a preferred embodiment, step S1 specifically includes: obtaining a thermal imaging image of the target area of ​​the multi-material biological 3D printing high-temperature printing nozzle in real time through a thermal imager; the computer communicates with the thermal imager through the SDK interface of the thermal imager, and receives and stores the thermal imaging image data in real time. This step ensures real-time monitoring of the temperature distribution of the high-temperature molten material and the hydrogel composite scaffold to avoid the influence of temperature fluctuations on cell activity.

[0054] In a preferred embodiment, step S2 specifically includes: using the U-net image segmentation algorithm to process the thermal imaging image and automatically segment the region of interest; extracting the temperature value of the region of interest, especially the temperature of the contact area between the high-temperature molten material and the hydrogel. This step effectively separates different temperature regions through the image segmentation algorithm, avoids noise interference, and ensures accurate extraction of temperature data.

[0055] In a preferred embodiment, step S3 specifically includes: transmitting the extracted temperature data to the Arduino control unit via a serial communication protocol; the Arduino control unit receives the temperature data and calculates the difference between the current temperature and the set target temperature. This step ensures that the temperature data is transmitted in real time, and subsequent temperature adjustment control is performed based on the difference.

[0056] In a preferred embodiment, step S4 specifically includes: calculating the fan power through a PID control algorithm or a threshold control algorithm according to the temperature difference or temperature value; adjusting the fan speed through a PWM signal to achieve precise adjustment of the temperature of the multi-material biological 3D printing nozzle to ensure that the high-temperature molten material will not damage the hydrogel cells during the molding process and maintain the biological activity of the overall structure.

[0057] See also Figure 2 , a temperature control system for a multi-material biological 3D printing high-temperature printing nozzle, comprising: a thermal imager, used to obtain a thermal imaging image of a target area of ​​a multi-material biological 3D printing high-temperature printing nozzle in real time and detect temperature distribution; a computer, communicating with the thermal imager, used to receive and process thermal imaging image data, and run an image segmentation algorithm to extract the temperature value of the area of ​​interest; a controller, connected to the computer through a serial port communication, used to receive temperature data transmitted by the computer, and calculate the fan power through a threshold control algorithm or a PID control algorithm according to the temperature value or the difference between the temperature and the set target temperature; a fan, connected to the controller, used to adjust the speed according to a control signal output by the controller, so as to achieve precise regulation of the temperature of the multi-material biological 3D printing nozzle.

[0058] In a preferred embodiment, the thermal imager communicates with the computer via an SDK interface, acquires a thermal imaging image of the target area in real time, and detects temperature distribution through image data.

[0059] In a preferred embodiment, the computer runs a U-net image segmentation algorithm to automatically segment the thermal imaging image, extract the temperature value of the region of interest, and avoid noise interference.

[0060] In a preferred embodiment, the controller is an Arduino controller, which receives temperature data transmitted by a computer through a serial communication protocol, and calculates the fan power through a PID control algorithm or a threshold control algorithm according to the temperature difference or temperature value.

[0061] In a preferred embodiment, the fan is connected to the controller via a PWM signal, and the rotation speed is adjusted according to the PWM signal output by the controller to achieve precise adjustment of the temperature of the multi-material biological 3D printing nozzle.

[0062] The multi-material biological 3D printing high-temperature printing nozzle temperature control method and system provided by the present invention obtains the thermal imaging temperature data of the nozzle nozzle target area in real time through a thermal imager, extracts the temperature value using the U-net image segmentation algorithm, and adjusts the fan power through PID control or threshold control, thereby achieving efficient and accurate temperature control. The system is particularly suitable for 3D printing of degradable material-hydrogel composite scaffolds in multi-material printing. It can obtain temperature information in real time through a thermal imager, and combine a controller (such as Arduino) to control fans and other equipment for precise adjustment, and control the temperature in real time within a range suitable for multi-material biological 3D printing, avoiding damage to hydrogel cells caused by high-temperature molten materials during the molding process, and maintaining the biological activity of the overall structure, which has important practical application value.

[0063] The following further describes specific embodiments of the present invention and examples of hardware control code implementation thereof.

[0064] 1. Hardware composition:

[0065] o Thermal imager: used to obtain temperature data of the target environment or area and detect temperature distribution through image data.

[0066] o Arduino controller: used to receive temperature data and control the power output of devices such as fans based on the temperature value.

[0067] o Fan: As a temperature control device, it adjusts power according to temperature to help lower or raise the ambient temperature.

[0068] o Computer / main control device: Runs image processing software to obtain image data from the thermal imager and extract temperature information.

[0069] 2. Software:

[0070] o Thermal Imager SDK: Provides a communication interface with the thermal imager, allowing the computer to acquire real-time image data and extract temperature information through image processing algorithms.

[0071] o U-net image segmentation algorithm: The U-net model is used to automatically segment thermal images, identify the region of interest, and accurately extract the temperature data of the region. Through this algorithm, the system can detect hot spots more accurately and avoid noise interference in traditional methods.

[0072] o Arduino control code: Based on the received temperature data, the fan power is adjusted through a PID control algorithm or a simple threshold control.

[0073] o Serial communication protocol: used for communication between computer and Arduino, transmitting temperature data and control instructions.

[0074] 3. Control methods:

[0075] o Data acquisition: The computer communicates with the thermal imager’s SDK interface to acquire thermal images of the target environment or area in real time.

[0076] o U-net image segmentation and temperature extraction: The U-net algorithm is used to segment the thermal imaging image and extract the temperature value of the area of ​​interest. The algorithm can effectively separate different temperature areas and accurately calculate the temperature data of the target area.

[0077] o Temperature transmission and processing: The extracted temperature data is transmitted to Arduino through serial communication. After receiving the data, Arduino determines the difference between the temperature and the set target temperature.

[0078] o PID control adjusts fan power: Based on the deviation between the received temperature and the set target temperature, the fan power is calculated using the PID control algorithm, and the fan speed is adjusted through the PWM signal to achieve precise temperature regulation.

[0079] o Threshold control: If complex PID control is not required, a simple temperature threshold control method can be used: when the temperature exceeds the set value, increase the fan power; when it is lower than the set value, reduce the fan power.

[0080] 4. Control effect:

[0081] o The system can accurately adjust the fan power according to the real-time temperature of the environment or target area to achieve automatic temperature adjustment.

[0082] o The PID control algorithm can ensure that the system temperature changes smoothly and avoid temperature fluctuations caused by over-adjustment.

[0083] o The system has a fast response speed and is suitable for environments and equipment that are sensitive to temperature changes.

[0084] Example

[0085] 1. Hardware design:

[0086] oThe thermal imager (FLUKE series) is connected to the computer via SDK.

[0087] o Arduino is used as the main control board, which is connected to the computer through the USB interface to receive temperature data and control the fan.

[0088] o The fan is controlled using a PWM signal, ensuring that the fan speed is adjustable in response to temperature changes.

[0089] 2. Software design:

[0090] o Use Python and thermal imager SDK for interface programming to achieve image acquisition and processing.

[0091] o The U-net image segmentation model is used on the computer to process the thermal imaging images.

[0092] Extract temperature information.

[0093] o The processed temperature data is sent to the

[0094] Arduino.

[0095] o The Arduino code adjusts the fan power through PID control algorithm or threshold control, and outputs PWM signal to control the fan speed.

[0096] Processing flow:

[0097] 1. The computer obtains the temperature image through the thermal imager and performs U-net image segmentation processing.

[0098] 2. Use U-net algorithm to segment the image and extract the temperature of the area of ​​interest.

[0099] 3. The computer sends the temperature data to the Arduino via the serial port.

[0100] 4.Arduino receives temperature data and calculates the difference from the set target temperature.

[0101] 5.Arduino calculates the fan power based on the difference using the PID control algorithm and outputs a PWM signal to control the fan.

[0102] 6. The fan adjusts the speed according to the PWM signal and adjusts the ambient temperature.

[0103] The following is a sample of the hardware control code:

[0104]

[0105] / / Check if there is data sent from Python to Arduino

[0106] if(Serial.available()>0){

[0107] / / Read the temperature value sent by Python

[0108] String tempString = Serial.readStringUntil('\n'); / / Read temperature value

[0109] Input = tempString.toFloat(); / / Convert the string to a floating temperature value

[0110] Serial.print("Received temperature:");

[0111] Serial.println(Input);

[0112] }

[0113] / / Use PID algorithm to calculate the fan power (0-255)

[0114] myPID.Compute();

[0115] / / Write the output PWM value to the fan control pin

[0116] analogWrite(fanPin,Output);

[0117] / / Optional: Print current temperature and fan power for debugging

[0118] Serial.print("Target Temp:");

[0119] Serial.print(Setpoint);

[0120] Serial.print("℃,Current Temp:");

[0121] Serial.print(Input);

[0122] Serial.print("℃,Fan Power:");

[0123] Serial.println(Output);

[0124] / / Wait for a while before executing the next loop

[0125] delay(1000);

[0126] }

[0127] Figure 3 This example shows how a computer uses a thermal imager to obtain a temperature image and performs U-net image segmentation processing. The vertical coordinate represents the temperature, and the xy coordinate is the pixel coordinate, which reflects the temperature value of each pixel in the thermal image. Figure 4 An example of using the U-net algorithm to segment an image and extract the temperature of an area of ​​interest in an embodiment of the present invention is shown.

[0128] The above embodiments of the present invention realize a complete and effective automatic temperature control solution, which uses a thermal imager and U-net image segmentation algorithm to accurately obtain temperature information, and controls the fan power through Arduino to adjust the temperature. The temperature can be controlled in real time within a range suitable for multi-material biological 3D printing, avoiding damage to hydrogel cells caused by high-temperature molten materials during the molding process, avoiding the influence of temperature fluctuations on cell activity, and maintaining the biological activity of the overall structure. The system has the advantages of high precision, strong real-time performance, strong automatic adaptability, etc., and has important practical application value.

[0129] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A method for controlling the temperature of a high-temperature printing nozzle for multi-material biological 3D printing, characterized in that: The following steps are involved: S1: The thermal imager performs real-time thermal imaging of the target area of ​​the high-temperature printing nozzle of multi-material biological 3D printing. The computer communicates with the thermal imager to obtain the thermal imaging image of the target area of ​​the nozzle in real time, and accurately monitors the temperature distribution of the high-temperature molten material and the hydrogel composite scaffold; S2: The thermal imaging image is processed using the U-net image segmentation algorithm to extract the temperature value of the area of ​​interest in the multi-material biological 3D printing nozzle, including the temperature of the contact area between the high-temperature molten material and the hydrogel; S3: The extracted temperature data is transmitted to the control unit via serial communication, and the control unit receives the data and calculates the difference between the temperature and the set target temperature; S4: According to the temperature value or temperature difference, the fan power is adjusted through a threshold control algorithm or a PID control algorithm to achieve precise regulation of the temperature of the multi-material biological 3D printing nozzle, so as to ensure that the high-temperature molten material will not damage the hydrogel cells during the molding process and maintain the biological activity of the overall structure.

2. The multi-material biological 3D printing high-temperature printing nozzle temperature control method according to claim 1, characterized in that: Step S1 specifically includes: Acquire a thermal imaging image of the target area of ​​a high-temperature printing nozzle for multi-material 3D bioprinting in real time using a thermal imager; The computer communicates with the thermal imager through the SDK interface of the thermal imager, and receives and stores the thermal imaging image data in real time.

3. The multi-material biological 3D printing high-temperature printing nozzle temperature control method according to claim 1 or 2, characterized in that: Step S2 specifically includes: The U-net image segmentation algorithm is used to process the thermal imaging image and automatically segment the region of interest; The temperature values ​​of the region of interest are extracted, especially the temperature of the region where the high temperature molten material contacts the hydrogel.

4. The method for controlling the temperature of a high-temperature printing nozzle for multi-material biological 3D printing according to any one of claims 1 to 3, characterized in that: Step S3 specifically includes: The extracted temperature data is transmitted to the Arduino control unit via the serial communication protocol; The Arduino control unit receives the temperature data and calculates the difference between the current temperature and the set target temperature.

5. The method for controlling the temperature of a high-temperature printing nozzle for multi-material biological 3D printing according to any one of claims 1 to 4, characterized in that: Step S4 specifically includes: According to the temperature difference or temperature value, the fan power is calculated by a PID control algorithm or a threshold control algorithm; By adjusting the fan speed through PWM signals, the temperature of the multi-material biological 3D printing nozzle can be precisely adjusted to ensure that the high-temperature molten material will not damage the hydrogel cells during the molding process and maintain the biological activity of the overall structure.

6. A multi-material biological 3D printing high-temperature printing nozzle temperature control system, comprising: Thermal imager, used to obtain real-time thermal imaging images of the target area of ​​the high-temperature printing nozzle of multi-material biological 3D printing and detect temperature distribution; A computer, communicating with the thermal imager, for receiving and processing thermal imaging image data and running an image segmentation algorithm to extract temperature values ​​of the region of interest; The controller is connected to the computer through a serial communication port, and is used to receive temperature data transmitted by the computer, and calculate the fan power through a threshold control algorithm or a PID control algorithm according to the temperature value or the difference between the temperature and the set target temperature; The fan is connected to the controller and is used to adjust the rotation speed according to the control signal output by the controller to achieve precise adjustment of the temperature of the multi-material biological 3D printing nozzle.

7. The multi-material biological 3D printing high temperature printing nozzle temperature control method according to claim 6, characterized in that: The thermal imager communicates with the computer through the SDK interface, acquires the thermal imaging image of the target area in real time, and detects the temperature distribution through the image data.

8. The multi-material biological 3D printing high-temperature printing nozzle temperature control system according to claim 6 or 7, characterized in that: The computer runs the U-net image segmentation algorithm to automatically segment the thermal imaging image, extract the temperature value of the area of ​​interest, and avoid noise interference.

9. The multi-material biological 3D printing high-temperature printing nozzle temperature control system according to any one of claims 6 to 8, characterized in that: The controller is an Arduino controller, which receives temperature data transmitted by a computer through a serial communication protocol, and calculates the fan power through a PID control algorithm or a threshold control algorithm according to the temperature difference or the temperature value.

10. The multi-material biological 3D printing high-temperature printing nozzle temperature control system according to any one of claims 6 to 9, characterized in that: The fan is connected to the controller via a PWM signal, and the rotation speed is adjusted according to the PWM signal output by the controller to achieve precise adjustment of the temperature of the multi-material biological 3D printing nozzle.

Images