Flexible microfluidic device design method and flexible microfluidic device

Abstract

The present application relates to a flexible microfluidic device design method, a flexible microfluidic device, a computer device and a storage medium. The method comprises: establishing a finite element model for a flexible substrate and simulating the stretching of the finite element model, obtaining stress distribution data of the flexible substrate, and determining the stress concentration area of ​​the flexible substrate according to the stress distribution data and a first threshold value, and when the stress concentration area does not meet the preset shape condition, changing the shape of the flexible substrate near the stress concentration area, and when the stress concentration area meets the preset shape condition, setting a microchannel at the median line of the isoforce line of the flexible substrate. The flexible microfluidic device obtained by the above design method improves the problem of microchannel collapse caused by excessive local stress of the flexible substrate during stretching, thereby largely solving the problem of microfluidic blocking during stretching, improving the reliability of the device, and extending the service life of the device.

Description

Technical Field

[0001] The present application relates to the field of microfluidic technology, and in particular to a design method for a flexible microfluidic device, a flexible microfluidic device, a computer device, and a storage medium. Background Art

[0002] With the development of microfluidic technology, flexible microfluidic electronic technology has gradually been used in research and applications in the fields of sports and medical treatment. For example, flexible microfluidic devices can be used to prepare flexible microfluidic motion sensors for continuous monitoring of the human body.

[0003] However, in the prior art, when the flexible microfluidic device is stretched, the internal stress distribution of the sensor substrate is limited by the geometric shape of the substrate. The unreasonable microchannel design causes the flexible conductive material of the sensor to be blocked during the stretching process, resulting in device failure. The use environment of flexible microfluidic sensors during human movement is more complicated. Therefore, analyzing the stress distribution of the flexible substrate and designing the microchannel according to the stress distribution is an urgent problem that needs to be solved in flexible microfluidic devices.

[0004] In the related art, there is a problem that the flexible conductive material of the substrate of the flexible microfluidic device is easily blocked during the stretching process, resulting in the failure of the flexible microfluidic device. Currently, no effective solution has been proposed. Summary of the invention

[0005] Based on this, it is necessary to provide a flexible microfluidic device design method, a flexible microfluidic device, a computer device and a storage medium to address the above technical problems.

[0006] To achieve the above object, the present invention adopts the following flexible microfluidic device design method, comprising the following steps:

[0007] According to preset stretching parameters, a finite element model of a flexible substrate of a first shape is simulated and stretched to obtain first stress distribution data of the flexible substrate of the first shape, and a first stress concentration area of ​​the flexible substrate of the first shape is determined according to the first stress distribution data of the flexible substrate of the first shape and a preset first threshold value;

[0008] In the case where the shape of the first stress concentration area does not meet the preset shape condition, the shape of the flexible substrate is changed according to the first stress concentration area to obtain a second shape of the flexible substrate, and according to the preset stretching parameters, the finite element model of the flexible substrate of the second shape is simulated and stretched to obtain second stress distribution data of the flexible substrate, and the second stress concentration area of ​​the flexible substrate of the second shape is determined according to the second stress distribution data of the flexible substrate and the preset first threshold value;

[0009] When the shape of the second stress concentration area meets the preset shape condition, a microchannel is arranged at the median line of the stress isotropic lines of the flexible substrate of the second shape.

[0010] In one embodiment, determining the stress concentration area of ​​the flexible substrate according to the stress distribution data of the flexible substrate and a preset first threshold, and comparing the shape of the stress concentration area with a preset shape condition comprises:

[0011] Dividing the flexible substrate into a first number of parts to obtain substrate units, obtaining stress distribution data of the flexible substrate, obtaining stress values ​​of the first number of substrate units according to the stress distribution data, and obtaining an average value of the stress values ​​of the substrate units;

[0012] The variance of the stress value of the substrate unit is calculated based on the average value. When the variance of the substrate unit is greater than or equal to a second threshold, the substrate unit is indicated as a stress concentration unit. When all the substrate units in a first region are the stress concentration units, the first region is indicated as a stress concentration region that does not meet the preset shape conditions, wherein the first region is a region whose shape does not meet the preset shape conditions.

[0013] In one embodiment, the simulating stretching of the finite element model of the flexible substrate of the first shape according to the preset stretching parameters includes:

[0014] A shape that meets the requirements of the application scenario and has the smallest volume is selected as the first shape, and a finite element model of the flexible substrate of the first shape is simulated and stretched according to preset stretching parameters.

[0015] In one embodiment, comparing the shape of the stress concentration area with the preset shape condition comprises:

[0016] The preset shape condition is determined according to a width of a narrowest portion of the first shape of the flexible substrate.

[0017] In one embodiment, changing the shape of the flexible substrate according to the first stress concentration area to obtain a second shape of the flexible substrate comprises:

[0018] When there is a groove in the flexible substrate near the first stress concentration area, the groove is filled and the depression of the groove is reduced to obtain the flexible substrate of the second shape.

[0019] In one embodiment, changing the shape of the flexible substrate according to the first stress concentration area to obtain a second shape of the flexible substrate comprises:

[0020] Near the first stress concentration region, the area of ​​the flexible substrate near the first stress concentration region is reduced to obtain the flexible substrate of the second shape.

[0021] According to another aspect of the present invention, a flexible microfluidic device is provided. The flexible microfluidic device comprises a flexible substrate and a liquid material. The flexible substrate is designed using the flexible microfluidic device design method described above. The liquid material is in the microchannel.

[0022] In one embodiment, the liquid material is a liquid conductive material or a non-Newtonian fluid.

[0023] According to another aspect of the present invention, there is also provided a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned flexible microfluidic device design method when executing the computer program.

[0024] According to another aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned flexible microfluidic device design method are implemented.

[0025] The above-mentioned flexible microfluidic device design method, flexible microfluidic device, computer equipment and storage medium establish a finite element model for the flexible substrate and simulate the stretching of the finite element model to obtain stress distribution data of the flexible substrate, and determine the stress concentration area of ​​the flexible substrate according to the stress distribution data and the first threshold value. When the first stress concentration area of ​​the flexible substrate of the first shape does not meet the preset shape condition, the shape of the flexible substrate near the first stress concentration area is changed to obtain the second shape of the flexible substrate. When the second stress concentration area of ​​the flexible substrate of the second shape meets the preset shape condition, a microchannel is set at the median line of the isoforce line of the flexible substrate. The flexible microfluidic device obtained by the above-mentioned design method has uniform stress distribution under preset stretching conditions, effectively improving the problem of microchannel collapse caused by excessive local stress of the flexible substrate during stretching, thereby largely solving the problem of easy blockage of microfluids during stretching, improving the reliability of device use, and extending the service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a flow chart of a method for designing a flexible microfluidic device according to one embodiment of the present invention;

[0027] Figure 2 is a flow chart of a method for designing a flexible microfluidic device according to another embodiment of the present invention;

[0028] Figure 3is a schematic diagram of changing the shape of a flexible substrate according to one embodiment of the present invention;

[0029] Figure 4 is a flow chart of a method for designing a flexible microfluidic device according to a specific embodiment of the present invention;

[0030] Figure 5 FIG. 1 is a schematic diagram of stress distribution of a flexible substrate according to a specific embodiment of the present invention. Figure 1 ;

[0031] Figure 6 FIG. 1 is a schematic diagram of stress distribution of a flexible substrate according to a specific embodiment of the present invention. Figure 2 ;

[0032] Figure 7 is a schematic diagram of a computer device according to one embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] The flexible microfluidic device design method provided in the present application can be applied to prepare flexible microfluidic devices that can continuously monitor the human body, such as motion sensors.

[0035] In one embodiment, Figure 1 FIG. 1 is a flow chart of a method for designing a flexible microfluidic device according to an embodiment of the present invention. Figure 1 As shown, a method for designing a flexible microfluidic device is provided, comprising the following steps:

[0036] Step S110, performing simulated stretching on the finite element model of the flexible substrate of the first shape according to preset stretching parameters, obtaining first stress distribution data of the flexible substrate, and determining a first stress concentration area of ​​the flexible substrate of the first shape according to the first stress distribution data of the flexible substrate and a preset first threshold;

[0037] In step S110, the stretching condition that will occur in the flexible substrate device during the application process is predicted, and preset stretching parameters and the first shape of the flexible substrate are set. The first shape can select the simplest geometric figure that can realize the function. For example, if there are three forces in different directions in the application scenario to stretch the flexible substrate, the first shape can be set to a three-ring shape. After selecting the first shape, the flexible substrate of the shape is modeled using a finite element model, and the stretching parameters are set according to the expected stretching condition. The finite element model is simulated for stretching. The stretching parameters include the position, distance and direction of the external force, etc., and the first stress distribution data of the flexible substrate of the first shape under the preset stretching parameters is obtained. According to the obtained first stress distribution data, the first stress concentration area of ​​the flexible substrate is determined according to the preset first threshold value. The first threshold value here is the magnitude of the stress value. The empirical value can be selected according to the properties of the flexible substrate, the liquid material and the application scenario of the flexible microfluidic device. The first threshold value can be a single value. For example, if the first threshold value is A, then the area where the stress distribution is greater than or equal to A is considered as the stress concentration area; optionally, the first threshold value can include two values. For example, the first threshold value includes A and B, and B is less than A. Then the area where the stress distribution is greater than or equal to A and the area where the stress distribution is less than or equal to B are considered as stress concentration areas. That is, the stress concentration area mentioned in this application refers to the area where the stress value is greatly different from the overall stress average value of the flexible substrate, including both the area with a larger stress value and the area with a smaller stress value. In addition, during the stretching process, multiple island-shaped stress concentration areas may appear in the flexible substrate.

[0038] Step S120, when the shape of the first stress concentration area does not meet the preset shape condition, the shape of the flexible substrate is changed according to the first stress concentration area to obtain a second shape of the flexible substrate, and according to the preset stretching parameters, the finite element model of the flexible substrate of the second shape is simulated and stretched to obtain second stress distribution data of the flexible substrate, and the second stress concentration area of ​​the flexible substrate of the second shape is determined according to the second stress distribution data of the flexible substrate and the preset first threshold value;

[0039] In step S120, the fact that the shape of the first stress concentration area does not meet the preset shape condition indicates that, among the stress concentration areas generated by the flexible substrate during the stretching process, there is a stress concentration area whose shape does not meet the preset shape condition. The preset shape condition may be the size of the area, or the condition of the length or width. For example, the preset shape condition may be that the width of the stress concentration area cannot be greater than 3 mm, or that the product of the stress concentration area cannot be greater than 5 mm×5 mm. In the case where the shape of the stress concentration area does not meet the shape condition, the shape of the flexible substrate near the stress concentration area is changed to obtain the second shape of the flexible substrate. When there are multiple stress concentration areas in the flexible substrate, each stress concentration area needs to be compared with the preset shape condition one by one, and the shapes near all stress concentration areas on the flexible substrate that do not meet the preset shape condition need to be changed. Then, according to the preset stretching parameters, the finite element model of the flexible substrate of the second shape is simulated and stretched, and the second stress concentration area of ​​the flexible substrate of the second shape is determined according to the method in step S110.

[0040] Step S130, when the shape of the second stress concentration area meets the preset shape condition, a microchannel is arranged at the median line of the stress isotropic lines of the flexible substrate of the second shape.

[0041] In step S130, each second stress concentration area needs to be compared with the preset shape conditions one by one. If it is determined that the shape of the stress concentration area on the flexible substrate of the second shape meets the preset shape conditions, the second shape is used as the final shape of the flexible substrate. Then, the various isoforce lines on the flexible substrate are obtained, and the median line of the isoforce line is selected to set the microfluidic channel. The selection of the median line of the above isoforce line should be carried out when the stress of the flexible substrate is relatively stable. For example, when a flexible substrate is stretched multiple times, when the stretching distance is 1% to 10% of the length of the flexible substrate, the stress distribution of the flexible substrate changes greatly, and when the stretching distance is 10% to 30% of the length of the flexible substrate, the stress distribution of the flexible substrate tends to be stable, which is conducive to the selection of the median line of the isoforce line.

[0042] In practical applications, steps S120 and S130 need to be optimized through multiple iterations, and the flexible substrate of the same shape needs to be simulated stretched under different stretching parameters, and the shape of the flexible substrate also needs to be constantly changed. Through the above-mentioned flexible microfluidic device design method, the stress distribution of the flexible microfluidic device is uniform under the preset stretching conditions, and the problem of microchannel collapse caused by excessive local stress of the flexible substrate during stretching is effectively improved, thereby largely solving the problem of microfluidic blocking during stretching, improving the reliability of the device, and extending the service life of the device.

[0043] In one embodiment, determining a stress concentration area of ​​a flexible substrate according to stress distribution data of the flexible substrate and a preset first threshold, and comparing the stress concentration area with a preset shape condition includes: dividing the flexible substrate into a first number of parts to obtain substrate units, acquiring stress distribution data of the flexible substrate, acquiring stress values ​​of the first number of substrate units according to the stress distribution data, and obtaining an average value of the stress values ​​of the substrate units; calculating the variance of the stress values ​​of the substrate units according to the average value, and indicating that the substrate unit is a stress concentration unit when the variance of the substrate unit is greater than or equal to a second threshold, and when all substrate units in the first area are stress concentration units, indicating that the first area is a stress concentration area that does not meet the preset shape condition, wherein the first area does not meet the preset shape condition.

[0044] In this embodiment, a method for comparing a stress concentration area with a preset shape condition is provided. First, the flexible substrate is divided into a first number of parts, each of which is regarded as a substrate unit, and then the finite element model of the flexible substrate is stretched in a simulated manner to obtain stress distribution data under various stretching conditions. According to the stress distribution data of the flexible substrate, the stress magnitude of each substrate unit can be obtained. Since flexible substrates are usually thin, the stress distribution of each cross section is regarded as the same. Although the above-mentioned division of the flexible substrate into the first number of parts is actually a division based on the volume of the flexible substrate, for the convenience of analysis, it can be regarded as a division of the cross section of a unit layer of the flexible substrate. Therefore, the subsequent comparison of stress concentration areas can also be regarded as a comparison based on area. Secondly, the stress value of each substrate unit of the flexible substrate is obtained according to the stress distribution data, and the average stress value of all substrate units is calculated. Calculate the stress value F of substrate element i i Relative to the average The variance C i , When the variance C iWhen it is greater than or equal to the second threshold, the substrate unit i is regarded as a stress concentration unit. Preferably, the second threshold is set to 2C, where C is the overall variance of the stress values ​​of all substrate units; optionally, the variances of the stress values ​​of all substrate units are arranged from large to small according to the values, and it is determined that the substrate units corresponding to the variances in the first 15% of the list are all stress concentration units. Finally, when all the substrate units in the first region are stress concentration units, the first region is a stress concentration area. If the first region does not meet the preset shape conditions, it does not meet the requirements of the substrate design, and the substrate shape near the first region needs to be further optimized. For example, the flexible substrate is divided into 10,000 regions, and according to the actual application scenario, only the stress concentration area smaller than 7×7 will not block the microchannel during the stretching process. Then the first region can be selected as a region greater than or equal to 7×7. When each substrate unit in the first region on the flexible substrate is a stress concentration unit, it means that the first region is a stress concentration area that does not meet the shape requirements. Through the method in this embodiment, the stress distribution of the flexible substrate can be quantitatively analyzed, the stress concentration area can be analyzed more efficiently, and the efficiency of calculation iteration in the design process of the flexible microfluidic device can be improved.

[0045] In one embodiment, Figure 2 FIG. 1 is a flow chart of a method for designing a flexible microfluidic device according to another embodiment of the present invention. Figure 2 As shown, according to the preset stretching parameters, simulating the stretching of the finite element model of the flexible substrate of the first shape includes:

[0046] Step S210 , selecting a shape that meets the requirements of the application scenario and has the smallest volume as a first shape, and performing simulated stretching on a finite element model of the flexible substrate of the first shape according to preset stretching parameters.

[0047] The method in this embodiment can establish a first shape according to different limiting conditions and create a finite element model of a flexible substrate. In addition to the simplest geometric figure that can realize the function, a more reasonable first shape can be obtained by adding limiting conditions, such as adding special requirements for the flexible substrate in the application scenario, such as adding a hanging hole if the substrate needs to be hung with other structures, or the shape of the shell needs to be met for easy embedding in the shell, etc. At the same time, the generated first shape can also be limited to have the smallest volume under other conditions, that is, the material required to manufacture the flexible substrate of the first shape is the least, making the first shape more practical. Through the above method in this embodiment, the number of subsequent iterations and optimizations of the first shape can be reduced while saving the material of the flexible substrate, thereby improving the calculation efficiency.

[0048] In one embodiment, the preset shape condition includes: determining the preset shape condition according to the width size of the narrowest width in the first shape of the flexible substrate. In this embodiment, since the first shape usually selects the shape with the least required material, that is, the first shape is usually the shape with the highest requirements for the stress concentration area during the iterative optimization process, the stress concentration area meets the shape requirements of the first shape of the flexible substrate for the stress concentration area, and also meets the requirements of the optimized second shape for the shape condition of the stress concentration area. Preferably, half of the width size of the narrowest width of the first shape of the flexible substrate is used as the requirement for the width of the stress concentration area in the shape condition. Optionally, during the iteration process, the shape requirements of the stress concentration area are adjusted according to the change of the shape of the flexible substrate. The shape conditions of the stress concentration area provided in this embodiment further improve the efficiency of iterative calculation of the flexible substrate while meeting the design requirements of the flexible substrate.

[0049] In one embodiment, changing the shape of the flexible substrate at the stress concentration area to obtain a second shape of the flexible substrate includes: filling the groove near the stress concentration area, reducing the degree of depression of the groove, and obtaining the second shape of the flexible substrate. Figure 3 Schematic diagram of changing the shape of a flexible substrate according to an embodiment of the present invention. Figure 3 As shown, when the stress in the stress concentration area is greater than the first threshold value and the first threshold value is greater than the average value of the stress value of the flexible substrate, the stress concentration area is generally near the groove of the flexible substrate, and the groove can be a position where the shape of the flexible substrate changes sharply, such as a notch, a hole, a groove, etc. In the above case, in order to reduce the size of the stress concentration area, when there is a groove in the flexible substrate, the area of ​​the flexible substrate is first increased to fill the angular area of ​​the groove to smooth the angular area. When the size of the stress concentration area is still greater than the size of the first area, the area of ​​the flexible substrate is continued to be increased, the concave angle of the groove is increased, or the concave depth of the groove is reduced. Through the method in this embodiment, when there is a stress concentration area with large stress in the flexible substrate, the shape of the flexible substrate can be optimized by locating and increasing the area of ​​the flexible substrate near the groove of the flexible substrate, and the shape adjustment of the flexible substrate is more accurately further limited by the adjustment rules, so that the optimization iteration process of the flexible substrate is more efficient.

[0050] In one embodiment, changing the shape of the flexible substrate according to the first stress concentration area to obtain the second shape of the flexible substrate includes: reducing the area of ​​the flexible substrate near the first stress concentration area near the first stress concentration area to obtain the flexible substrate of the second shape. In this embodiment, a method for changing the shape of the flexible substrate is provided when the stress in the stress concentration area is less than the first threshold value and the first threshold value is less than the stress average value, that is, reducing the area of ​​the flexible substrate near the stress concentration area, so that after the shape is changed, the stress in the area is appropriately increased, and the purpose of saving the flexible substrate material and making the flexible substrate lighter is achieved while making the stress distribution of the flexible substrate more uniform.

[0051] According to another aspect of the present invention, a flexible microfluidic device is provided, which includes a flexible substrate and a liquid material; the shape of the flexible substrate is obtained according to the above-mentioned design method of the microfluidic device and a microchannel is set at the median line of the stress isoline of the flexible substrate, and the liquid is set in the microchannel.

[0052] In one embodiment, the liquid material of the flexible microfluidic device is a liquid conductive material or a non-Newtonian fluid. The liquid material includes liquid metal, and the liquid metal is used as a conductor; the non-Newtonian liquid includes polyethylene, polyacrylamide, polyvinyl chloride, rubber solution or silk protein extract, etc. The non-Newtonian fluid can protect other components or conductive circuits in the flexible microfluidic device.

[0053] The above-mentioned flexible microfluidic device utilizes the substrate shape of the flexible device and the stress distribution during the stretching process to design the geometric configuration of the microchannel, effectively improving the problem of microchannel collapse caused by excessive local stress when the flexible substrate is stretched, thereby largely solving the problem of microfluids (liquid materials) being easily blocked during stretching, improving the reliability of the device and extending the service life of the device.

[0054] In a specific embodiment, Figure 4 FIG. 1 is a flow chart of a method for designing a flexible microfluidic device according to a specific embodiment of the present invention. Figure 4 As shown, the design method of the flexible microfluidic device includes the following steps:

[0055] Step S410, obtaining a preliminary design of the flexible substrate, and obtaining a preliminary design of the flexible substrate according to the specific position requirements of the device. In this embodiment, the function is realized with the simplest geometric shape, and a finger ring shape is obtained, that is, a first shape with two circular rings connected by a rectangle in the middle, and a finite element model is established according to the first shape.

[0056] Step S420, setting the stretching conditions, setting the stretching parameters of the flexible substrate. In this embodiment, the stretching position is set inside the circle of the two rings, and the stretching direction is to stretch toward both sides along the center connecting line of the two rings.

[0057] Step S430, simulating the stretching process to obtain the stress distribution of the flexible substrate. Using the finite element model, the stress distribution inside the flexible substrate is calculated under the preset stretching parameters. In this embodiment, it is set that the flexible substrate is stretched to 130% of the initial length along the center connecting line of the two rings. During the stretching process, the stress distribution is observed when the length of the flexible substrate is stretched to 101%, 110%, 120% and 130% of the initial length.

[0058] Step S440, determining whether there is a stress concentration area in the flexible substrate during the directional stretching process.

[0059] Step S450, when there is a stress concentration area during the stretching process of the flexible substrate, the shape is adjusted and iterative optimization is performed. The shape of the flexible substrate near the stress concentration area is adjusted to adjust the stress distribution state of the area.

[0060] In step S440 and step S450, Figure 5 FIG. 1 is a schematic diagram of stress distribution of a flexible substrate according to a specific embodiment of the present invention. Figure 1 , Figure 6 FIG. 1 is a schematic diagram of stress distribution of a flexible substrate according to a specific embodiment of the present invention. Figure 2 , showing Figure 5 Schematic diagram of stretching a flexible substrate to 130% of its initial length and a partial magnification is shown. Figure 5 , Figure 6As shown, the first shape of the flexible substrate is a goggle type (Goggle). After the stress distribution of the flexible substrate is obtained, the flexible substrate is subjected to quantitative stress analysis. In the stress analysis, the flexible substrate is divided into 7000 substrate units. After reaching the tension setting position, the stress value of each substrate unit, as well as the stress average value and the overall variance of the 7000 substrate units are obtained, and then the variance of each substrate unit is calculated based on the stress average value and the stress value of each substrate unit. The data is analyzed. If the variance of the substrate units in the 5×5 area is greater than or equal to twice the overall variance, the area is considered to be a stress concentration area. After calculation, the flexible substrate with the shape of Goggle has a stress concentration area. The geometric shape design near the stress concentration area is adjusted. Since the stress value of the stress concentration area of ​​the first shape flexible substrate is smaller than the average stress value, the area of ​​the flexible substrate near the area should be reduced. The finger ring shape is designed with the least material. The middle of the two rings is connected with a material with the same width as the finger ring width, and the shape of the flexible substrate is a dumbbell (Dumbbell). The flexible substrate is stretched to both sides along the center connecting line of the two circular rings to 130% of the initial length again to determine whether there is a stress concentration area in the flexible substrate during the directional stretching process. In the stress analysis, the dumbbell-shaped flexible substrate has a stress concentration area with a large stress value variance. The geometric shape design near the stress concentration area is adjusted again. Since the stress value of the stress concentration area of ​​the dumbbell-shaped flexible substrate is larger than the average stress value, the area of ​​the flexible substrate near this area should be increased to fill the groove in the shape, so that the depression of the groove part is reduced and the groove becomes smooth, thereby obtaining a spindle-shaped flexible substrate.

[0061] Step S460, when there is no stress concentration area during the stretching process of the flexible substrate, the microchannel distribution design is performed. When there is no stress concentration area during the stretching process of the flexible substrate, the shape of the flexible substrate is the second shape, and according to the stress distribution of the flexible substrate of the second shape, the microchannel design is performed at the median line of the isoforce line of the stress distribution.

[0062] In the above specific embodiment, the flexible substrate is still stretched to 130% of the initial length along the center connecting line of the two rings to determine whether there is a stress concentration area in the directional stretching process of the flexible substrate. In the regional stress analysis, the spindle-shaped flexible substrate does not have a stress concentration area, but has a stress stable area, that is, the spindle shape is the second shape of the flexible substrate.

[0063] Step S470, obtaining an optimal design result. Combining the second shape of the flexible substrate and the design of the microchannel, a final design of the flexible microfluidic device is obtained.

[0064] Step S480, verify the simulation results. According to the final design scheme, a spindle-shaped flexible microfluidic device is prepared, and the microchannel of the device is filled with liquid metal. The device is placed on a Kell uniaxial tensile testing machine, and the device is stretched to 30% of its initial length along the center connecting line of the two rings. The stretching is repeated 10,000 times. When the relative standard deviation of the liquid metal resistance value in the microchannel is less than 10% each time it is stretched to 30%, and there is no liquid metal microchannel blocking, which can prove the accuracy of the simulation results.

[0065] According to another aspect of the present invention, a computer device is provided. In one embodiment, a computer device is provided. Figure 7 Schematic diagram of a computer device according to an embodiment of the present invention. The computer device may be a terminal. The internal structure diagram thereof may be as follows: Figure 7 As shown. The computer device includes a processor, a memory, a network interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for designing a flexible microfluidic device is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device housing, or an external keyboard, touchpad or mouse, etc.

[0066] The above-mentioned computer device establishes a finite element model for the flexible substrate and simulates stretching of the finite element model to obtain stress distribution data of the flexible substrate, and determines the stress concentration area of ​​the flexible substrate according to the stress distribution data and the first threshold value. When the first stress concentration area of ​​the flexible substrate in the first shape does not meet the preset shape condition, the shape of the flexible substrate near the first stress concentration area is changed to obtain the second shape of the flexible substrate. When the second stress concentration area of ​​the flexible substrate in the second shape meets the preset shape condition, a microchannel is set at the median line of the isoforce line of the flexible substrate. The flexible microfluidic device obtained by the above-mentioned design method has uniform stress distribution under preset stretching conditions, effectively improving the problem of microchannel collapse caused by excessive local stress of the flexible substrate during stretching, thereby largely solving the problem of easy blockage of microfluids during stretching, improving the reliability of device use, and extending the service life of the device.

[0067] According to another aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned flexible microfluidic device design method is implemented.

[0068] The computer-readable storage medium establishes a finite element model for the flexible substrate and simulates stretching of the finite element model to obtain stress distribution data of the flexible substrate, and determines the stress concentration area of ​​the flexible substrate according to the stress distribution data and a first threshold value. When the first stress concentration area of ​​the flexible substrate in a first shape does not meet the preset shape condition, the shape of the flexible substrate near the first stress concentration area is changed to obtain the second shape of the flexible substrate. When the second stress concentration area of ​​the flexible substrate in a second shape meets the preset shape condition, a microchannel is set at the median line of the isoforce line of the flexible substrate. The flexible microfluidic device obtained by the design method has uniform stress distribution under preset stretching conditions, effectively improving the problem of microchannel collapse caused by excessive local stress of the flexible substrate during stretching, thereby largely solving the problem of easy blockage of the microfluid during stretching, improving the reliability of the device and extending the service life of the device.

[0069] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0070] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for designing a flexible microfluidic device, characterized in that: The method comprises: According to preset stretching parameters, a finite element model of a flexible substrate of a first shape is simulated and stretched to obtain first stress distribution data of the flexible substrate of the first shape, and a first stress concentration area of ​​the flexible substrate of the first shape is determined according to the first stress distribution data of the flexible substrate of the first shape and a preset first threshold value; In the case where the shape of the first stress concentration area does not meet the preset shape condition, the shape of the flexible substrate is changed according to the first stress concentration area to obtain a second shape of the flexible substrate, and according to the preset stretching parameters, the finite element model of the flexible substrate of the second shape is simulated and stretched to obtain second stress distribution data of the flexible substrate, and the second stress concentration area of ​​the flexible substrate of the second shape is determined according to the second stress distribution data of the flexible substrate and the preset first threshold value; When the shape of the second stress concentration area meets the preset shape condition, a microchannel is arranged at the median line of the stress isotropic lines of the flexible substrate of the second shape.

2. The method for designing a flexible microfluidic device according to claim 1, characterized in that: The step of determining the stress concentration area of ​​the flexible substrate according to the stress distribution data of the flexible substrate and a preset first threshold value, and comparing the shape of the stress concentration area with a preset shape condition comprises: Dividing the flexible substrate into a first number of parts to obtain substrate units, obtaining stress distribution data of the flexible substrate, obtaining stress values ​​of the first number of substrate units according to the stress distribution data, and obtaining an average value of the stress values ​​of the substrate units; The variance of the stress value of the substrate unit is calculated based on the average value. When the variance of the substrate unit is greater than or equal to a second threshold, the substrate unit is indicated as a stress concentration unit. When all the substrate units in a first region are the stress concentration units, the first region is indicated as a stress concentration area that does not meet the preset shape condition, wherein the first region does not meet the preset shape condition.

3. The method for designing a flexible microfluidic device according to claim 1, characterized in that: The simulating stretching of the finite element model of the flexible substrate of the first shape according to the preset stretching parameters includes: A shape that meets the requirements of the application scenario and has the smallest volume is selected as the first shape, and a finite element model of the flexible substrate of the first shape is simulated and stretched according to preset stretching parameters.

4. The method for designing a flexible microfluidic device according to claim 1, characterized in that: The comparing the shape of the stress concentration area with a preset shape condition comprises: The preset shape condition is determined according to a width of a narrowest portion of the first shape of the flexible substrate.

5. The method for designing a flexible microfluidic device according to claim 1, characterized in that: Changing the shape of the flexible substrate according to the first stress concentration area to obtain a second shape of the flexible substrate comprises: When there is a groove in the flexible substrate near the first stress concentration area, the groove is filled and the depression of the groove is reduced to obtain the flexible substrate of the second shape.

6. The method for designing a flexible microfluidic device according to claim 1, characterized in that: Changing the shape of the flexible substrate according to the first stress concentration area to obtain a second shape of the flexible substrate comprises: Near the first stress concentration region, the area of ​​the flexible substrate near the first stress concentration region is reduced to obtain the flexible substrate of the second shape.

7. A flexible microfluidic device, characterized in that: The flexible microfluidic device comprises a flexible substrate and a liquid material. The flexible substrate is designed using the flexible microfluidic device design method according to any one of claims 1 to 6. The liquid material is in the microchannel.

8. The flexible microfluidic device according to claim 7, characterized in that: The liquid material is a liquid conductive material or a non-Newtonian fluid.

9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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