Method for adjusting and controlling spiral shape of homogenate material by fitting printing track through rope winding effect

Abstract

The invention provides a method for regulating and controlling the spiral shape of a homogenate material by fitting a printing track through a rope winding effect. The method specifically comprises the following steps: printing homogenate by adopting an extrusion type printing technology, and adjusting the height of a spray head to trigger a rope winding effect in a muscle homogenate falling process so as to print different winding shapes; different printing shapes are recorded, geometric data of the shapes are measured to fit a mathematical model, and the relation between the printing speed and the height of the spray head and the spiral radius and the spiral spacing is established; a prediction code is constructed through a mathematical model, and a user can input different spiral geometric parameters to obtain a prediction printing parameter combination; and printing the spiral shape of the required muscle homogenate by utilizing the predicted data. According to the method, common physical phenomena in the nature are utilized, a stable spiral structure is generated in the printing process, the control problem of the spiral shape is greatly simplified, meanwhile, printing flexibility is achieved, the needed spiral shape is predicted by establishing a mathematical model, and the efficient and reliable production process can be achieved.

Description

Technical Field

[0001] The invention relates to the field of material science and technology, and in particular to a method for regulating the spiral shape of a homogenized material by fitting a printing trajectory using a winding rope effect. Background Art

[0002] In the field of materials science, extrusion printing plays a very important role. This is a printing method in which biological materials are extruded through a nozzle and deposited on a substrate. It has the advantages of wide application and easy operation. Although extrusion printing technology can control the printing shape through computer simulation paths, the construction of spiral shapes requires complex voxel-based path planning algorithms and optimized curve fitting technology to generate continuous sub-paths, while ensuring that the printer has high stability and high-precision printing capabilities. Some researchers have developed smart materials with self-assembly or self-repairing capabilities, which can adjust their shape or function through environmental stimulation during or after printing. However, this also places strict requirements on the materials, so at this stage, the printing of such complex and flexible spiral structures is still challenging.

[0003] In physics, the phenomenon that falling liquids produce different coiling shapes is called the rope effect. Adjusting the nozzle height during printing can induce this natural phenomenon, producing a series of continuous winding trajectories. Simply adding a printing height parameter can greatly simplify the control problem of the spiral shape. In 2015, Professor John Ronald Lister of fluid mechanics at the University of Cambridge extruded and printed sticky bees at a certain height onto a moving conveyor belt, obtaining a series of continuous spiral trajectories. He developed a mathematical model for motion prediction using printing speed and winding speed. However, since the material winding speed is not a common printing parameter, it is difficult to measure the value, which limits its application. Summary of the invention

[0004] In view of the shortcomings of the above-mentioned prior art, the present invention provides a method for regulating the spiral shape of the slurry material by fitting the printing trajectory using the rope-winding effect. The present invention utilizes the rope-winding effect to increase the nozzle height parameter H, so as to produce a stable spiral structure during the printing process, thereby simplifying the control problem of the spiral shape and having printing flexibility. By establishing a mathematical model to predict and manufacture the required spiral shape, an efficient and reliable production process can be achieved to meet the needs of specific applications.

[0005] In order to achieve the above technical purpose, the present invention provides a method for regulating the spiral shape of a slurry material by fitting a printing trajectory using a winding rope effect, which specifically includes the following steps:

[0006] S1. Extrusion printing: Use extrusion printing technology to print the slurry material, adjust the appropriate nozzle height to trigger the rope effect of the slurry material falling process, and print out different winding shapes;

[0007] S2. Fitting mathematical model: record the printed shape of extrusion printing, measure the spiral shape geometric data, fit the mathematical model of the binary quadratic function relationship between the printing parameter combination and the spiral shape geometric data, and establish a visual function relationship in MATLAB; the printing parameters include the printing speed V and the nozzle height H; the spiral shape geometric data include the spiral radius R and the spiral pitch L;

[0008] S3. Constructing prediction code: A prediction code is constructed by fitting a mathematical model of a binary quadratic function relationship between a printing parameter combination and spiral shape geometric data, so that the user inputs the required spiral shape geometric data R and L into the code command line window of the computer to obtain the corresponding printing parameter combination V and H;

[0009] S4. Spiral manufacturing: Use a combination of printing parameters to print out the desired homogenate spiral shape.

[0010] A further technical solution of the present invention is as follows: the homogenate material of step S1 is muscle homogenate, which is prepared by cutting, grinding and emulsifying fresh muscle tissue; the prepared muscle homogenate is loaded into a syringe, a needle of suitable diameter is selected, and an extrusion printer is used to adjust the nozzle height and moving speed, and the winding and stacking of the material are achieved through the winding effect, so that the material is naturally wound to form a regular spiral structure; the fresh muscle tissue comes from different types of animals.

[0011] A further technical solution of the present invention is as follows: In the step S2, the geometric data of the same regular spiral shape, namely the spiral radius R and the pitch L, are collected, and a mathematical model ft of the binary quadratic function relationship between the nozzle height H and the printing speed V and the radius R and the pitch L is fitted, and a visual function relationship is established in matlab, and the establishment process is as follows:

[0012] S201. Define a matrix with four data in each row, representing the values ​​of H, V, L and R respectively, and then input the data of nozzle height H and printing speed V, measured spiral radius R and pitch L into the matrix, and use this data set as the basis for model training; then extract each column in the matrix into a separate variable, H and V are the predicted variables, R and L are the independent variables used, use the fit function to perform polynomial fitting on the data, and obtain a quadratic polynomial surface model 'poly22', the general form is:

[0013] f(x,y)=p00+p10*x+p01*y+p20*x^2+p11*x*y+p02*y^2;

[0014] It is stipulated that H=p 00 +p 10 *L+p 01*R+p 20 *L^2+p 11 *L*R+p 02 *R^2;

[0015] V=q 00 +q 10 *L+q 01 *R+q 20 *L^2+q 11 *L*R+q 02 *R^2;

[0016] S202. Use the coeffvalues ​​function to extract the coefficients of the fitted surface model ft and store them in the coefficients vector; assign each coefficient in the coefficients vector to the corresponding variable p 00 、p 10 、p 01 、p 20 、p 11 、p 02 ,q 00 ,q 10 ,q 01 ,q 20 ,q 11 ,q 02 In the above, we get the specific mathematical relationship between H, V and L, R, and output the function expressions of H and V through the disp function;

[0017] S203. Use the meshgrid function to generate a grid for creating a series of points within the range of L and R, and use linspace(min(L), max(L), 50) and linspace(min(R), max(R), 50) to generate 50 equally spaced points between the minimum and maximum values ​​of L and R respectively; specify that ft_H and ft_V are functions of H and V obtained in step S202, and use the feval function to calculate the values ​​of H and V at the generated grid points; then use the figure function to create a new graphics window, and use subplot(1,2,1) and subplot(1,2,2) to divide the graphics window into one row and two columns, which are used to display the function graphs of V and H respectively; use the surf function to draw a three-dimensional surface graph and establish a visual functional relationship between V and H and L and R.

[0018] A further technical solution of the present invention: The process of constructing the code by the mathematical model in step S3 is as follows:

[0019] (1) Prompt the user to enter the values ​​of R and L through the input function, and store the input values ​​in the R_input and L_input variables;

[0020] (2) Use @(R_input, L_input) to define an anonymous function with the variable name getHFromLR, which is used to accept two input parameters R_input and L_input;

[0021] (3) The input R_input and L_input are passed to the surface model ft_H fitted in step S201 through feval, so as to calculate the corresponding H. Finally, the value of H is output through the disp function, which is the predicted value of H.

[0022] (4) Use the same method to create a function named getVFromRL to accept two input parameters R_input and L_input. Similarly, use the feval function to pass the input R_input and L_input to the surface model ft_V fitted in step S203, and output the corresponding V value, which is the predicted value of V.

[0023] A preferred technical solution of the present invention: in the step S4, the printing parameters obtained in the step S3 are input into the printer for actual printing, and the spiral radius R and the spiral pitch L at different positions on a spiral shape are observed to be the same, ensuring that the deviation range is: R≤0.2mm, L≤0.5mm, so as to ensure the uniformity of the spiral; if it is found that the deviation exceeds the deviation range, H and V are further adjusted according to the model and actual results; when R has a deviation, H can be reduced, and when L has a deviation, V can be increased or decreased, so as to ensure the accuracy of the printing effect and produce the muscle homogenate with the desired spiral shape.

[0024] The preferred technical solution of the present invention: the preparation process of the muscle homogenate is as follows:

[0025] (1) fresh muscle tissue was taken, rinsed with PBS solution to remove blood clots on the surface, fat tissue and fascia tissue on the surface were removed, and then rinsed with PBS solution again, and processed into pieces with scissors and a micro-tissue grinder, with the size of the pieces less than 2 cm×2 cm×2 cm; the fresh muscle tissue was derived from pork, beef or rat meat;

[0026] (2) placing the processed muscle tissue into a centrifuge tube, adding grinding beads, and grinding it in a grinder for 4 to 6 times to remove the cord-like fibers in the tissue after grinding;

[0027] (3) The muscle tissue treated in step (2) is sequentially passed through filters with pore sizes of 1.2 mm, 1.0 mm, and 0.8 mm to be emulsified and formed into a homogenate, i.e., the pork homogenate.

[0028] A further technical solution of the present invention: In step S202, for the meandering spiral, the fitting formula is:

[0029] H=2+(3.2228e-16)*L+5*R+(-9.8648e-17)*L^2+(1.3684e-15)*L*R+(-5.7281e-15)*R^2;

[0030] V=-2.1673+3.013*L+(-21.5702)*R+(-0.48841)*L^2+4.0699*L*R+4.9531*R^2;

[0031] For the spiral helix, the fitting formula is:

[0032] H=3+(7.0578e-15)*L+2*R+(-4.5963e-16)*L^2+(-2.5908e-15)*L*R+0*R^2;

[0033] V=0.76101+0.50603*L+(-1.6387*R)+(-0.017816*L^2)+(-0.16536*L*R)+0.73438*R^2.

[0034] Spiral manufacturing: By inputting the required radius R and pitch L, the corresponding nozzle height H and printing speed V are obtained, and the obtained printing parameters are input into the printer for actual printing, and the final generated spiral shape is verified to see whether it meets the design requirements. Specifically, it is to observe whether the spiral radius R and spiral pitch L at different positions on a section of the spiral shape are the same to ensure the uniformity of the spiral. If deviations are found, the parameters can be further adjusted according to the model and actual results to ensure the accuracy of the printing effect and produce the muscle homogenate with the required spiral shape.

[0035] The spiral shape of the slurry material is controlled by fitting the printing trajectory using the winding rope effect. By introducing physical effects and mathematical models, a new method in the field of material shape design and manufacturing is provided.

[0036] The present invention takes pork muscle homogenate as an example, adjusts the nozzle height to trigger the rope-winding effect of the muscle homogenate falling process, prints out different winding shapes, establishes the relationship between printing parameters (printing speed, nozzle height) and spiral geometric data (spiral radius, spiral pitch), and constructs a code. The user can input different spiral geometric parameters to obtain a predicted printing parameter combination, and finally use the predicted data to print out the desired muscle homogenate spiral shape, which solves the shape control problem of actually using the rope-winding effect to print the spiral, and provides a new method in the field of material shape design and manufacturing.

[0037] The falling liquid will produce different coiling shapes, which is the rope effect. Its physical principle mainly involves the interaction between the viscosity, gravity and inertial force of the fluid, which requires certain viscosity of the material. The spiral printing track is actually the result of the superposition of the nozzle movement in the horizontal direction and the rope effect in the vertical direction. By adjusting the nozzle height H, the degree of the rope effect is adjusted to achieve the control of the spiral shape. The method of using the measured geometric data to build a database and develop prediction codes is a simple and accurate prediction method that can achieve efficient and reliable production processes, meet the needs of specific applications, and reduce the cost of repeated experiments and trial and error.

[0038] The present invention utilizes common physical phenomena in nature and increases the nozzle height parameter H to produce a stable spiral structure during the printing process, which greatly simplifies the control problem of the spiral shape while having printing flexibility. By establishing a mathematical model to predict and manufacture the required spiral shape, an efficient and reliable production process can be achieved to meet the needs of specific applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Two regular spiral structures printed using the rope-winding effect;

[0040] Figure 2 A method for measuring geometric parameters of helical structures;

[0041] Figure 3 The data sets are two types of spiral structures;

[0042] Figure 4 Screenshot of code to build the mathematical relationship between H, V and L, R of the helical structure;

[0043] Figure 5 Screenshot of the code for visualizing the helical structures H, V and L, R;

[0044] Figure 6 Visual models of two helical structures H, V and L, R;

[0045] Figure 7 Print parameter code screenshots for development prediction;

[0046] Figure 8 Verification screenshots for both spiral printing effects. DETAILED DESCRIPTION

[0047] The present invention is described in detail below in conjunction with the embodiments, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more explicit definition of the protection scope of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0048] A method for adjusting the spiral shape of a slurry material by fitting a printing trajectory using a winding rope effect is provided in the first embodiment, and the specific steps are as follows:

[0049] S1. Using the rope-winding effect, two regular spiral structures were printed using pork muscle homogenate. Figure 1 As shown; the details are as follows:

[0050] (1) First, take the muscle tissue of the pig, rinse it with PBS solution to remove the blood clots on the surface, remove the fat tissue and fascia tissue on the surface, and rinse it with PBS solution again. Use scissors and a micro-tissue grinder to process it into pieces with a size less than 2cm×2cm×2cm. Put the above-treated muscle tissue into a 5mL centrifuge tube, add an 8mm grinding bead to each tube, put it into the grinder and grind it 5 times (60 Hz, 60 seconds), and remove the strip-like fibers in the tissue after grinding. The above-treated muscle tissue is passed through 1.2mm, 1.0mm, and 0.8mm pore size filters in turn to emulsify and form a homogenate. The prepared pork muscle homogenate is loaded into a 5ml syringe and a 16G needle is selected. Using an extrusion printer, adjust the nozzle height within the range of 2cm-7cm, adjust the moving speed within the range of 0-3mm / s, and realize the winding and stacking of the material through the rope effect, so that the material is naturally wound to form a regular spiral structure.

[0051] (2) Since the shapes of the slurry coiling and folding are different at different nozzle heights H, two relatively regular shapes were selected as research objects. According to the definition of Professor John Ronald Lister of fluid mechanics at the University of Cambridge, the shape on the left is meanders, and the shape on the right is coiling.

[0052] (3) By controlling the variable method, the printing speed and all other parameters remain unchanged, the nozzle height is adjusted, the printed shape is observed, and the parameter range for the two shapes to appear stably is determined. For the serpentine shape, a nozzle height that is too low is not conducive to the coiling of the homogenate rope, and the accumulated homogenate will also clog the nozzle. A nozzle height that is too high will cause the homogenate rope to change from a pendulum-like motion in the horizontal direction to an approximately circular motion. Finally, for the muscle homogenate material, the height range of the serpentine shape can be induced to be 3-4cm. For the coil shape, the regular trajectory requires the winding speed to match the printing speed. At too high a height, the winding pattern of the liquid rope is irregular. Finally, for the muscle homogenate material, the height range of the regular coil shape can be induced to be 5-6cm.

[0053] S2. Record the printed shape of the extrusion print, measure the spiral shape geometry data, and the measurement method of the spiral structure geometry parameters, such as Figure 2 As shown, the specific method is as follows:

[0054] (1) After determining the printing range, select the nozzle height and keep it fixed, adjust the printing speed, that is, the moving speed of the nozzle, observe the shape of the slurry coil at the same height, determine the printing speed range that can form a spiral shape, and repeat the test three times for the boundary speed. For the serpentine spiral, we keep the nozzle height constant within the height range of 3-4cm, and increase the printing speed by 0.1mm / s each time from V=0 until a regular spiral shape appears. Taking H=3 as an example, the spiral shape begins to appear at V=0.7. Specifically, on this spiral shape, the spiral radius R and spiral spacing L at different positions are the same, which proves the uniformity of the spiral. If the results of three repetitions are all spirals, then V=0.7 is the lower boundary when H=3. Continue to increase the printing speed by 0.1mm / s each time. At V=1.2, the spiral is still uniform, but at V=1.3, the shape printed is irregular. No uniform spiral appears in the three repetitions, indicating that V=1.2 is the upper boundary of H=3. In this way, we get a spiral printing speed range of height (H=3). In the same way, we can measure the speed range of spiral printing when H=3.5 and H=4, and the speed boundary of coil shape when H=5, H=5.5, and H=6;

[0055] (2) Within the spiral printing speed range, record the spiral shape information at different speeds. Use a measuring ruler to measure the spiral geometric parameters: spiral distance and spiral radius.

[0056] S3. Datasets of two helical structures, such as Figure 3 As shown, the specific method is as follows:

[0057] At S301, we collect geometric information of the same regular spiral shape, namely, the spiral radius R (unit: mm) and the pitch L (unit: mm) as well as the corresponding nozzle height H (unit: mm) and printing speed V (unit: mm / s);

[0058] S302 defines a matrix in MATLAB with four data in each row, representing the values ​​of H, V, L and R respectively. The measured data is input into the matrix to obtain a data set, which is the basis for model training. Then we extract each column in the matrix into separate variables. H and V are the variables we want to predict, and R and L are the independent variables we use.

[0059] S4. The mathematical relationship between the helical structure H, V and L, R is constructed using code, such as Figure 4 As shown, the specific method is as follows:

[0060] S401 We extract the columns of the matrix in S302 into separate variables, H and V are the predicted variables, and R and L are the independent variables used;

[0061] S402 uses the fit function to perform polynomial fitting on the data and obtains a quadratic polynomial surface model 'poly22', the general form of which is:

[0062] f(x,y)=p00+p10*x+p01*y+p20*x^2+p11*x*y+p02*y^2;

[0063] It is stipulated that H=p 00 +p 10 *L+p 01 *R+p 20 *L^2+p 11 *L*R+p 02 *R^2;

[0064] V=q 00 +q 10 *L+q 01 *R+q 20 *L^2+q 11 *L*R+q 02 *R^2;

[0065] S403. Use the coeffvalues ​​function to extract the coefficients of the fitted surface model ft and store them in the coefficients vector; assign each coefficient in the coefficients vector to the corresponding variable p 00 、p 10 、p 01 、p 20 、p 11 、p 02 ,q00 ,q 10 ,q 01 ,q 20 ,q 11 ,q 02 In the above, we get the specific mathematical relationship between H, V and L, R, and output the function expressions of H and V through the disp function;

[0066] For the meandering spiral, the fitting formula is: H = 2 + (3.2228e-16) * L + 5 * R + (-9.8648e-17) * L^2 + (1.3684e-15) * L * R + (-5.7281e-15) * R^2;

[0067] V=-2.1673+3.013*L+(-21.5702)*R+(-0.48841)*L^2+4.0699*L*R+4.9531*R^2;

[0068] For the spiral helix, the fitting formula is:

[0069] H=3+(7.0578e-15)*L+2*R+(-4.5963e-16)*L^2+(-2.5908e-15)*L*R+0*R^2;

[0070] V=0.76101+0.50603*L+(-1.6387)*R+(-0.017816)*L^2+(-0.16536)*L*R+0.73438*R^2.

[0071] S5. Visual model construction code of helical structures H, V, L, and R, such as Figure 5 As shown, the specific method is as follows: use the meshgrid function to generate a grid to create a series of points within the range of L and R, and use linspace(min(L), max(L), 50) and linspace(min(R), max(R), 50) to generate 50 equally spaced points between the minimum and maximum values ​​of L and R respectively; specify that ft_H and ft_V are functions of H and V obtained in step S303, and use the feval function to calculate the values ​​of H and V at the generated grid points; then use the figure function to create a new graphics window, and use subplot(1,2,1) and subplot(1,2,2) to divide the graphics window into one row and two columns, which are used to display the function graphs of H and V respectively; use the surf function to draw a three-dimensional surface graph and establish a visual functional relationship between H and V and L and R. Visual model construction code, such as Figure 5 As shown in the figure, the function graphs of the parameters H, V and L, R of the two spiral structures are as follows: Figure 6 shown.

[0072] S6. Develop predictive printing parameter codes, such as Figure 7 As shown, the specific method is as follows:

[0073] (1) To obtain printing parameters, the user is prompted to enter the values ​​of R and L through the input function, and the input values ​​are stored in the R_input and L_input variables;

[0074] (2) Taking the prediction of H as an example, an anonymous function with the variable name getHFromLR is defined, and an anonymous function is defined with @(R_input, L_input), which accepts two input parameters R_input and L_input;

[0075] (3) The input R_input and L_input are passed to the fitting surface model ft_H of S304 through feval, so as to calculate the corresponding H value. feval(ft_H,L_input,R_input) is the function body of the anonymous function, which means that when this anonymous function is called, it will calculate the value of ft_H at the given L_input and R_input; finally, the value of H is output through the disp function, which is the predicted printing parameter H.

[0076] (4) The same method is used to create a function named getVFromRL, which receives R_input and L_input as parameters, uses the feval function to pass the input R_input and L_input to the surface model ft_V fitted in step S201, and outputs the corresponding V value.

[0077] Spiral printing effect verification, such as Figure 8 As shown, the specific method is as follows:

[0078] (1) Input the geometric parameters (L and R) of the required spiral into the prediction code to obtain the predicted printing parameters (V and H); for the winding shape, we input 3 sets of data L=3, R=0.2; L=3.5, R=0.3; L=4, R=0.4. After running the code, the predicted printing parameters are: V=0.8, H=3; V=0.64, H=3.5; V=0.75, H=4. For the coil shape, we input L=4, R=1.5; L=4.5, R=1; L=5, R=1.5. After running the code, the predicted printing parameters are: V=0.7, H=6; V=1.03, H=5; V=0.8, H=6;

[0079] (2) Input the predicted V into the printer, adjust the nozzle to the height H, and print the prepared slurry;

[0080] (3) Record the spiral shape at different speeds. Measure the actual geometric parameters of the spiral and calculate the error rate of the parameter, error rate = error ÷ actual value × 100%. For the winding shape, the actual R of the three sets of data obtained is almost error-free, and the actual L is 3.15, 3.38, and 4.20, and the corresponding error rates are 4.8%, 3.6%, and 5%, respectively, all less than 10%; for the coil shape, the actual R of the three sets of data obtained is almost error-free, and the actual L is 4.14, 4.60, and 5.50, and the corresponding error rates are 3.4%, 2.2%, and 9.1%, respectively. Therefore, we conclude that the error rate of the spiral printed by the predicted parameters is less than 10%, and the spiral with the shape of the required muscle homogenate is successfully manufactured.

[0081] The above is only one embodiment of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the attached claims.

Claims

1. A method for regulating the spiral shape of a slurry material by fitting a printing trajectory using a winding rope effect, characterized in that The following steps are involved: S1. Extrusion printing: Use extrusion printing technology to print the slurry material, adjust the appropriate nozzle height to trigger the rope effect of the slurry material falling process, and print out different winding shapes; S2. Fitting mathematical model: record the printed shape of extrusion printing, measure the spiral shape geometric data, fit the mathematical model of the binary quadratic function relationship between the printing parameter combination and the spiral shape geometric data, and establish a visual function relationship in MATLAB; the printing parameters include the printing speed V and the nozzle height H; the spiral shape geometric data include the spiral radius R and the spiral pitch L; S3. Constructing prediction code: A prediction code is constructed by fitting a mathematical model of a binary quadratic function relationship between a printing parameter combination and spiral shape geometric data, so that the user inputs the required spiral shape geometric data R and L into the code command line window of the computer to obtain the corresponding printing parameter combination V and H; S4. Spiral manufacturing: Use a combination of printing parameters to print out the desired homogenate spiral shape.

2. The method of controlling the spiral shape of a slurry material by fitting a printing trajectory using a winding rope effect according to claim 1, characterized in that: The homogenate material of step S1 is muscle homogenate, which is prepared by cutting, grinding and emulsifying fresh muscle tissue. The prepared muscle homogenate is loaded into a syringe, a needle of suitable diameter is selected, and an extrusion printer is used to adjust the nozzle height and moving speed. The material is wound and stacked through the winding effect, so that the material is naturally wound to form a regular spiral structure; the fresh muscle tissue comes from different types of animals.

3. The method of controlling the spiral shape of a slurry material by fitting a printing trajectory using a winding rope effect according to claim 1, characterized in that: In the step S2, the geometric data of the same regular spiral shape, namely the spiral radius R and the pitch L, are collected, and the mathematical model ft of the binary quadratic function relationship between the nozzle height H and the printing speed V and the radius R and the pitch L is fitted, and a visual function relationship is established in matlab. The establishment process is as follows: S201. Define a matrix with four data in each row, representing the values ​​of H, V, L and R respectively, and then input the data of nozzle height H and printing speed V, measured spiral radius R and pitch L into the matrix, and use this data set as the basis for model training; then extract each column in the matrix into a separate variable, H and V are the predicted variables, R and L are the independent variables used, use the fit function to perform polynomial fitting on the data, and obtain a quadratic polynomial surface model 'poly22', the general form is: f(x,y)=p00+p10*x+p01*y+p20*x^2+p11*x*y+p02*y^2; It is stipulated that H=p 00 +p 10 *L+p 01 *R+p 20 *L^2+p 11 *L*R+p 02 *R^2; V=q 00 +q 10 *L+q 01 *R+q 20 *L^2+q 11 *L*R+q 02 *R^2; S202. Use the coeffvalues ​​function to extract the coefficients of the fitted surface model ft and store them in the coefficients vector; assign each coefficient in the coefficients vector to the corresponding variable p 00 、p 10 、p 01 、p 20 、p 11 、p 02 ,q 00 ,q 10 ,q 01 ,q 20 ,q 11 ,q 02 In the above, we get the specific mathematical relationship between H, V and L, R, and output the function expressions of H and V through the disp function; S203. Use the meshgrid function to generate a grid for creating a series of points within the range of L and R, and use linspace(min(L), max(L), 50) and linspace(min(R), max(R), 50) to generate 50 equally spaced points between the minimum and maximum values ​​of L and R respectively; specify that ft_H and ft_V are functions of H and V obtained in step S202, and use the feval function to calculate the values ​​of H and V at the generated grid points; then use the figure function to create a new graphics window, and use subplot(1,2,1) and subplot(1,2,2) to divide the graphics window into one row and two columns, which are used to display the function graphs of V and H respectively; use the surf function to draw a three-dimensional surface graph and establish a visual functional relationship between V and H and L and R.

4. The method of controlling the spiral shape of a slurry material by fitting a printing trajectory using a rope winding effect according to claim 3, characterized in that: The process of constructing the code through the mathematical model in the S3 step is as follows: (1) Prompt the user to enter the values ​​of R and L through the input function, and store the input values ​​in the R_input and L_input variables; (2) Use @(R_input, L_input) to define an anonymous function with the variable name getHFromLR, which is used to accept two input parameters R_input and L_input; (3) The input R_input and L_input are passed to the surface model ft_H fitted in step S201 through feval, so as to calculate the corresponding H. Finally, the value of H is output through the disp function, which is the predicted value of H. (4) Use the same method to create a function named getVFromRL to accept two input parameters R_input and L_input. Similarly, use the feval function to pass the input R_input and L_input to the surface model ft_V fitted in step S203, and output the corresponding V value, which is the predicted value of V.

5. The method of controlling the spiral shape of a slurry material by fitting a printing trajectory using a rope winding effect according to claim 1, characterized in that: In the step S4, the printing parameters obtained in the step S3 are input into the printer for actual printing, and the spiral radius R and the spiral pitch L at different positions on a spiral shape are observed to be the same, and the deviation range is ensured: R≤0.2mm, L≤0.5mm, so as to ensure the uniformity of the spiral; if it is found that the deviation exceeds the deviation range, H and V are further adjusted according to the model and actual results; when R has a deviation, H can be reduced, and when L has a deviation, V can be increased or decreased, so as to ensure the accuracy of the printing effect and produce the muscle homogenate with the desired spiral shape.

6. The method of controlling the spiral shape of a slurry material by fitting a printing trajectory using a rope winding effect according to claim 2, characterized in that: The preparation process of the muscle homogenate is as follows: (1) fresh muscle tissue was taken, rinsed with PBS solution to remove blood clots on the surface, fat tissue and fascia tissue on the surface were removed, and then rinsed with PBS solution again, and processed into pieces with scissors and a micro-tissue grinder, with the size of the pieces less than 2 cm×2 cm×2 cm; the fresh muscle tissue was derived from pork, beef or rat meat; (2) placing the processed muscle tissue in a centrifuge tube, adding grinding beads, and grinding it in a grinder for 4 to 6 times to remove the cord-like fibers in the tissue after grinding; (3) The muscle tissue treated in step (2) is sequentially passed through filters with pore sizes of 1.2 mm, 1.0 mm, and 0.8 mm to be emulsified and formed into a homogenate, i.e., the pork homogenate.

7. The method of controlling the spiral shape of a slurry material by fitting a printing trajectory using a winding rope effect according to claim 2, characterized in that: In step S202, for the meandering spiral, the fitting formula is: H = 2 + (3.2228e-16) * L + 5 * R + (-9.8648e-17) * L^2 + (1.3684e-15) * L * R + (-5.7281e-15) * R^2; V=-2.1673+3.013*L+(-21.5702)*R+(-0.48841)*L^2+4.0699*L*R+4.9531*R^2; For the spiral helix, the fitting formula is: H=3+(7.0578e-15)*L+2*R+(-4.5963e-16)*L^2+(-2.5908e-15)*L*R+0*R^2; V=0.76101+0.50603*L+(-1.6387*R)+(-0.017816*L^2)+(-0.16536*L*R)+0.73438*R^2.

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