Multiphase particle control method for regulating meniscus through magnetic field response microneedle

Abstract

The invention belongs to the technical field of open surface control, and particularly relates to a multiphase particle control method for regulating and controlling a meniscus through a magnetic field response microneedle. According to the invention, the pose of the magnetic control microneedle is changed by utilizing the change of a magnetic field, and the deformation of an asymmetric meniscus is generated on a fluid interface; the deformation of the asymmetric meniscus provides an interfacial tension horizontal component difference for a control object, and the control object comprises solid-phase particles, liquid-phase particles or gas-phase particles; the interface tension horizontal component difference is used for driving the control object to conduct multifunctional movement, and the multifunctional movement comprises one or more of capturing, rotating, transmitting and in-situ releasing of the control object. The asymmetric meniscus is generated by using the inclined microneedle, multiphase and multifunctional control is realized by adjusting the form of the meniscus, flexible, lossless, multi-material and multifunctional operation can be realized on an open surface, the range of controllable materials and the control environment are widened, the motion control mode is enriched, and the application and development prospects are wider.

Description

Technical Field

[0001] The present invention belongs to the technical field of open surface manipulation, and in particular relates to a multi-phase particle manipulation method for regulating a meniscus by a microneedle in response to a magnetic field. Background Art

[0002] Open Droplet Microfluidics refers to the manipulation of discrete droplets with tiny volumes on an open surface. The sample preparation, screening, and detection functions in traditional laboratories are integrated into a microchip with a surface area of ​​several square centimeters. Open droplet microfluidics not only has the advantages of traditional microfluidics, such as small reagent volume, precise manipulation, large specific surface area, and high integration. It also has unique advantages such as easy online analysis, good compatibility, and avoidance of cross contamination. It shows great application prospects and development potential in the fields of biomedicine, fine chemicals, materials science, and testing.

[0003] Nowadays, various external fields, including light, electrostatics, and heat, have been studied in open surface manipulation technologies, through the generation of polarized charges or directional flow fields for attraction and movement, and non-contact operation. However, these strategies mainly focus on specific materials, and high energy input can cause damage due to thermal damage or electrostatic breakdown. Magnetic fields with long-range, fast response, high penetration, and low-energy impact are a versatile and flexible approach. However, due to the difficulty of constraining and precisely controlling magnetic fields, or the limited structure of the implementation method and the limited material properties, it is difficult to take into account the technical requirements of non-destructive, flexible, and non-contact, making it difficult to achieve non-destructive and multifunctional control on open surfaces, limiting the practical application of manipulation control methods. Summary of the invention

[0004] The purpose of the present invention is to provide a method for multi-phase particle manipulation by regulating the meniscus with a microneedle in response to a magnetic field. The method provided by the present invention can realize flexible, non-destructive, multi-material and multi-functional operations on an open surface.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for manipulating multiphase particles by regulating a meniscus with a microneedle in response to a magnetic field, comprising the following steps:

[0007] The position of the magnetically controlled microneedle is changed by changing the magnetic field, so as to generate an asymmetric meniscus deformation on the fluid interface; the asymmetric meniscus deformation provides a horizontal component difference of the interfacial tension for the controlled object, and the controlled object includes solid phase particles, liquid phase particles or gas phase particles;

[0008] The horizontal component difference of the interfacial tension is used to drive the controlled object to perform multifunctional motion, wherein the multifunctional motion includes one or more of the controlled object being captured, rotated, transported and released in situ.

[0009] Preferably, the application form of the magnetically controlled microneedle includes a single magnetically controlled microneedle or a magnetically controlled microneedle array.

[0010] Preferably, the length of the single magnetically controlled microneedle is 1 to 5 mm, and the bottom radius is 0.15 to 0.5 mm; the single magnetically controlled microneedle is a free single magnetically controlled microneedle.

[0011] Preferably, the length of any single magnetically controlled microneedle in the magnetically controlled microneedle array is 1 to 5 mm, and the bottom radius is 0.15 to 0.5 mm;

[0012] The spacing distance between any two adjacent magnetically controlled microneedles in the magnetically controlled microneedle array is 1 to 2 times the length of a single magnetically controlled microneedle.

[0013] Preferably, the posture of the single magnetically controlled microneedle includes swinging and translation.

[0014] Preferably, when the magnetically controlled microneedle is a magnetically controlled microneedle array, the multifunctional motion is directed transmission; the directed transmission is that the controlled object is transmitted along the arrangement direction of the magnetically controlled microneedles in the magnetically controlled microneedle array.

[0015] Preferably, the controlled object includes bubbles, droplets, hydrogel particles or hard particles; and the radius of the controlled object is greater than 0.5 mm.

[0016] Preferably, the fluid interface comprises a gas-liquid interface or a liquid-liquid interface.

[0017] The present invention provides a method for manipulating multiphase particles by regulating a meniscus by a microneedle in response to a magnetic field, comprising the following steps: utilizing a change in a magnetic field to change the posture of a magnetically controlled microneedle, thereby generating a deformation of an asymmetric meniscus on a fluid interface; the deformation of the asymmetric meniscus provides a horizontal component difference of an interfacial tension for a controlled object, wherein the controlled object includes solid-phase particles, liquid-phase particles or gas-phase particles; utilizing the horizontal component difference of the interfacial tension to drive the controlled object to perform a multifunctional movement, wherein the multifunctional movement includes one or more of the controlled object being captured, rotated, transmitted and released in situ. Compared with the prior art, the present invention has the following technical effects: the present invention uses a magnetically controlled microneedle to generate an asymmetric meniscus, controls the position (including swinging and translation) of the magnetically controlled microneedle by changing the magnetic field to control the deformation (including the rising height and the position) of the asymmetric meniscus, and provides a horizontal component difference of the interfacial tension to drive the control object in the interface environment. Thus, the present invention controls the position of the magnetically controlled microneedle by changing the magnetic field, realizes the precise regulation of the asymmetric meniscus morphology of the fluid interface, and then realizes the flexible, lossless and precise motion control of the control object (i.e., multiphase particles), overcoming the limitation that the magnetic field control is difficult to precisely control. The control objects of the method provided by the present invention cover solid, liquid and gas three-phase particles, significantly broadening the scope of the control objects and the control environment, and is not limited to magnetically responsive materials. Finally, the present invention realizes the multifunctional operation of capturing, rotating, transmitting and releasing the control object in situ, enriches the motion control mode, enhances the universality of the control method in application, and improves the practicality and application prospect of the multiphase particle manipulation method, which is suitable for a wider range of functional materials and microparticle manipulation in complex environments.

[0018] Furthermore, in the present invention, when the magnetically controlled microneedle is a magnetically controlled microneedle array, the multifunctional motion is that the controlled object is directional-transmitted by the magnetically controlled microneedle array; the directional transmission is performed along the direction of the magnetically controlled microneedle array. In the magnetically controlled microneedle array, the transmission motion of the controlled object between the magnetically controlled microneedles is realized by changing the liquid surface equilibrium state through the posture relationship of the two needles. When the posture relationship of the microneedles changes, the liquid surface height will change accordingly, and the liquid surface height near the two needles will differ accordingly, and the directional transmission function of the controlled object is realized by controlling the difference.

[0019] In summary, the multiphase particle manipulation method of regulating the meniscus by a magnetic field-responsive microneedle provided by the present invention utilizes a tilted microneedle to generate an asymmetric meniscus, and adjusts the meniscus morphology to achieve multiphase and multifunctional control, such as the capture, rotation, transmission and in-situ release of bubbles, droplets and solid particles, which broadens the range of controllable materials, controls the environment, enriches the motion control mode, and has broader application and development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1A flowchart of the method for controlling multiphase particles by regulating the meniscus with a magnetic field-responsive microneedle provided by the present invention;

[0021] Figure 2 It is a schematic diagram of the manipulation of a free single magnetically controlled microneedle in the present invention;

[0022] Figure 3 Schematic diagram of the motion state of a free single magnetically controlled microneedle to control the magnetic field position and change the motion;

[0023] Figure 4 A top view schematic diagram of the rotation control of the present invention;

[0024] Figure 5 The basic process of particle transfer in a magnetically controlled microneedle array composed of three magnetically controlled microneedles;

[0025] Figure 6 Schematic diagram of the meniscus change process;

[0026] Figure 7 This is the force analysis diagram of the control object affected by the meniscus. Figure 7 (1) in the figure is the resting state diagram. Figure 7 (2) and (3) in are the capture and transmission processes. Figure 7 (4) in the figure is the in situ release process;

[0027] Figure 8 The process of attracting particles of different materials, where the scale bar is 1 mm;

[0028] Fig. 9 This is a real picture taken with a confocal microscope, showing how the interface morphology can be changed by controlling the angle.

[0029] Fig.10 The magnetically controlled microneedle array controls the movement of droplets, where the scale bar is 1 mm;

[0030] Fig.11 The magnetically controlled microneedle controls the droplets of different solutions to achieve continuous staged microchemical reactions, where the scale bar is 1 mm long;

[0031] Fig.12 is a graph showing the relationship between the radius of the controlled object in the present invention, the ratio of the distance between any two adjacent magnetically controlled microneedles in the magnetically controlled microneedle array, and the directional transmission speed;

[0032] Fig.13 It is a relationship diagram between the volume of the controlled object, the length of the magnetically controlled microneedle, the change in the distance between any two adjacent magnetically controlled microneedles in the magnetically controlled microneedle array and the actual driving effect in the present invention. DETAILED DESCRIPTION

[0033] The present invention provides a method for manipulating multiphase particles by regulating a meniscus with a microneedle in response to a magnetic field, comprising the following steps:

[0034] The position of the magnetically controlled microneedle is changed by changing the magnetic field, so as to generate an asymmetric meniscus deformation on the fluid interface; the asymmetric meniscus deformation provides a horizontal component difference of the interfacial tension for the controlled object, and the controlled object includes solid phase particles, liquid phase particles or gas phase particles;

[0035] The difference in the horizontal component of the interfacial tension is used to drive the controlled object to perform a multifunctional movement, wherein the multifunctional movement includes one or more of the controlled object being captured, rotated, transported, and released in situ.

[0036] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0037] Figure 1 The flowchart of the multi-phase particle manipulation method of the magnetic field responsive microneedle regulating the meniscus provided by the present invention. Figure 1 It can be seen that the present invention mainly generates an asymmetric meniscus on the fluid interface through a magnetically controlled microneedle to perform multifunctional motion control on the controlled object.

[0038] Combine the following Figure 1 The multi-phase particle manipulation method for regulating the meniscus by a magnetic field-responsive microneedle provided by the present invention is described in detail.

[0039] The present invention utilizes the change of magnetic field to change the position of magnetically controlled microneedles, and generates an asymmetric meniscus on the fluid interface. The asymmetric meniscus generated around the microneedle has differences in height and morphology, so that the controlled object is driven by the difference in the horizontal component of the interfacial tension brought about by the interface change, and due to this asymmetric difference, it has the ability to follow the meniscus on the inclined side of the microneedle, thereby realizing multifunctional movement.

[0040] In the present invention, the definition of meniscus is: Liquid meniscus refers to the curved surface formed near the contact area when liquid contacts a solid surface or another medium (such as gas or another liquid). The shape of the meniscus is determined by factors such as surface tension, contact angle and gravity, and usually appears as a curved interface. (e.g. Figure 6). Among them, the asymmetry comes from the tilt angle, and the detailed explanation is: based on the Young-Laplace equation, there is interfacial tension in the tangent direction of the highest point of the meniscus, which is balanced with the gravity of the meniscus itself in the vertical direction. Changing the angle between the tangent and the vertical direction can change the mass of the lifted liquid surface, thereby achieving the purpose of changing the rising height of the meniscus. For magnetically controlled microneedles, this angle is different on both sides due to the tilt, so asymmetry occurs. In the present invention, it is worth noting that the basic principle Young-Laplace equation is a conclusion in fluid mechanics, and the common manifestation is capillary phenomenon, etc. However, the present invention emphasizes the interface morphology control method based on the Young-Laplace equation theory.

[0041] In the present invention, Figure 6 The process of the meniscus changing on the inclined side when the magnetically controlled microneedle swings from a horizontal stationary state to a vertical state is demonstrated. Figure 6 (1) and Figure 6 (2) In the process of increasing the inclination angle α, the meniscus is fixed at the end of the microneedle and does not migrate. Only the angle φ between the tangential and vertical directions of the interface in the Young-Laplace equation changes, which increases the height of the meniscus. Figure 6 (3) and Figure 6 The process (4) in the above is a breakthrough Figure 6 In state (2), after the edge is pinned, the angle φ changes with the change of the inclination angle α and the contact angle θ, resulting in the change of the meniscus. As the inclination angle α increases, the meniscus height h decreases. Figure 6 The maximum height of the meniscus is obtained in (2) (when φ=α+θ-π / 2), which is the result of the interfacial pinning effect under the influence of the length of the magnetically controlled microneedle and the Young-Laplace equation. Figure 6 The parameters appearing in the figure are: φ is the angle between the liquid surface and the vertical direction, θ is the contact angle, and α is the inclination angle of the magnetically controlled microneedle.

[0042] In the present invention, the interfacial pinning effect is a phenomenon in which the liquid boundary (usually the three-phase contact line) is "pinned" due to surface inhomogeneity (such as roughness, chemical heterogeneity). Intuitively speaking, before reaching the above boundary value, the three-phase contact line always exists at the end of the magnetically controlled microneedle.

[0043] The present invention utilizes the change of magnetic field to change the posture of the magnetically controlled microneedle, and produces the deformation of the asymmetric meniscus on the fluid interface. In the present invention, the magnetically controlled microneedle is controlled by the change of magnetic field, and the morphology of the asymmetric meniscus is continuously and dynamically changed. The fluid interface is a two-phase fluid interface, and the fluid interface is preferably a smooth liquid-infused porous surface (slippery liquid-infused porous surface, SLIPS). The fluid interface preferably includes a gas-liquid interface or a liquid-liquid interface. The gas-liquid interface can be an air-water interface, an air-silicone oil interface, or an air-other organic liquid interface with fluidity. The liquid-liquid interface can be any two types of immiscible liquids.

[0044] In the present invention, the shape of the magnetically controlled microneedle preferably includes a cylindrical shape, a ciliary shape, a cone shape, a mushroom head shape, or a variant structure with a longitudinal and / or transverse texture structure surface modification. The magnetically controlled microneedle has magnetic responsiveness and can be used as an independent unit or as a basic unit for collective control. In the present invention, the material of the magnetically controlled microneedle is preferably stainless steel, a shape memory polymer or an alloy. In the present invention, when the real-time responsiveness and flexibility of the multifunctional movement of the controlled object are not required but need to be durable, the material of the magnetically controlled microneedle can be a shape memory polymer or an alloy.

[0045] In the present invention, the magnetically controlled microneedle includes a single magnetically controlled microneedle or a magnetically controlled microneedle array. The single magnetically controlled microneedle is a free single magnetically controlled microneedle. The position of the free single magnetically controlled microneedle can be changed freely, that is, it can be translated. The present invention uses the change of the magnetic field to change the posture of the magnetically controlled microneedle, and the posture of the single magnetically controlled microneedle includes swinging and translation. The posture of the magnetically controlled microneedle array is the change in the posture relationship between any two adjacent magnetically controlled microneedles.

[0046] In the present invention, the magnetron microneedle can preferably be surface modified to change its contact angle with water or oil.

[0047] In an embodiment of the present invention, the method for preparing the manipulation environment of the free single magnetically controlled microneedle preferably comprises: spin coating a polytetrafluoroethylene suspension on a glass substrate, heating and sintering, and then injecting dimethyl silicone oil to make it.

[0048] In an embodiment of the present invention, the substrate of the magnetron microneedle array manipulation environment is preferably formed by first casting and curing Ecoflex material and then injecting dimethyl silicone oil.

[0049] In the present invention, the method of generating the magnetic field preferably relies on external magnet induction and the three-axis electromagnetic coil relies on signal generator control.

[0050] In the present invention, the deformation of the asymmetric meniscus includes the change in height and position of the asymmetric meniscus. The present invention utilizes the change in magnetic field to change the position of the magnetically controlled microneedle, and produces the deformation of the asymmetric meniscus on the fluid interface, thereby realizing the precise control of the fluid interface morphology by the magnetic field. In the present invention, the fluid interface morphology is characterized by the deformation of the asymmetric meniscus.

[0051] In the present invention, since the change of the asymmetric meniscus is jointly affected by the radius and length of the magnetically controlled microneedle (i.e., the height of the asymmetric meniscus is proportional to the change in the radius and length of the magnetically controlled microneedle), and in order not to affect the operational ability of the magnetically controlled microneedle, the length of the single magnetically controlled microneedle is preferably 1 to 5 mm, and the bottom radius is preferably 0.15 to 0.5 mm.

[0052] In the present invention, the magnetically controlled microneedle array is formed by arranging two or more single magnetically controlled microneedles, and the monomers in the magnetically controlled microneedle array are non-free single magnetically controlled microneedles, that is, the position of any single magnetically controlled microneedle in the magnetically controlled microneedle array cannot be changed.

[0053] In the present invention, the length of any single magnetically controlled microneedle in the magnetically controlled microneedle array is preferably 1 to 5 mm, and the bottom radius is preferably 0.15 to 0.5 mm. The spacing between any two adjacent magnetically controlled microneedles in the magnetically controlled microneedle array is related to the length of the controlled object, such as Fig.12 As shown in FIG. 1 , when the size of the magnetically controlled microneedle is determined, the smaller the ratio of the particle radius of the controlled object to the distance between any two adjacent magnetically controlled microneedles in the magnetically controlled microneedle array is, the greater the average speed of the controlled object is, and the better the control effect on the controlled object is; at the same time, Fig.13 It can be seen that the smaller the particle size of the controlled object and the more the microneedle spacing in the magnetically controlled microneedle array matches the length of the microneedle, the better the control effect. In the present invention, the spacing between any two adjacent magnetically controlled microneedles in the magnetically controlled microneedle array is preferably 1 to 2 times the length of a single magnetically controlled microneedle.

[0054] After the deformation of the asymmetric meniscus is obtained, the deformation of the asymmetric meniscus is used to provide a horizontal component difference of the interfacial tension. After the horizontal component difference of the interfacial tension is obtained, the present invention uses the horizontal component difference of the interfacial tension to drive the controlled object to perform multifunctional motion, and the controlled object includes solid phase particles, liquid phase particles or gas phase particles, and the multifunctional motion includes one or more of the controlled object being captured, rotated, transmitted and released in situ. In the present invention, the horizontal component difference of the interfacial tension that can be provided by the asymmetric meniscus is also asymmetric. The controlled object is driven to always follow the meniscus on the inclined side to achieve multifunctional motion.

[0055] In the present invention, the controlled object preferably includes bubbles, droplets, hydrogel particles or hard particles. The radius of the controlled object is preferably greater than 0.5 mm.

[0056] In the present invention, when the magnetically controlled microneedle is a free single magnetically controlled microneedle, the posture of the free single magnetically controlled microneedle includes swinging and translation, and the multifunctional motion includes one or more of the controlled object being captured, rotated, transmitted and released in situ.

[0057] In the present invention, Figure 2 Schematic diagram of the movements that can be achieved by a single free magnetically controlled microneedle and its process.

[0058] In the present invention, when the magnetically controlled microneedle is a free single magnetically controlled microneedle, the present invention utilizes the free single magnetically controlled microneedle to tilt and change the morphology of the interface between the two phases of the fluid, which is specifically manifested as: the interface rises higher on the tilted side (e.g. Figure 6 ) while the other side has a lower rising height and a larger angle between the three-phase contact line and the vertical direction. This morphological change leads to differences in the ability to control particles in different directions, that is, a higher liquid level has a stronger attraction.

[0059] Therefore, there are the following multifunctional movement forms of the control object:

[0060] Capture process: The liquid level of the magnetically controlled microneedle structure is raised to raise the liquid level on one side of the controlled object, causing the force on it to change in the horizontal direction and move toward the magnetically controlled microneedle (such as Figure 7 The magnetic control method for controlling the swing angle and direction is as follows: Figure 3 As shown in the left figure.

[0061] Transmission and rotation process: Due to the above reasons, the force state of the control object (such as Figure 7 (3) in the figure is the basic state during the transmission and rotation process. The controlled object will be continuously dragged to follow the real-time change of the meniscus position of the magnetically controlled microneedle and move with the magnetically controlled microneedle. The translation magnetic field (such as Figure 3 The right figure in the figure) will achieve transmission, while changing the magnetic field position (such as Figure 3 The left figure in the figure) will change the swing angle and direction to realize the rotation of the needle, the rotation of the meniscus and even the rotation of the controlled object (such as Figure 4 shown).

[0062] In-situ release process: Using the same principle, the magnetically controlled microneedle is swung to the opposite direction, which will reduce the attraction and control ability of the controlled object. Figure 3 The magnetic field manipulation method on the left.

[0063] Figure 7 This is the force analysis diagram of the control object affected by the meniscus. Figure 7 (1) in the figure is the resting state diagram. Figure 7 (2) and (3) in are the capture and transmission processes. Figure 7(4) in the figure is the in situ release process. Figure 7 (1) represents the resting state of the particle when it is uncontrolled, and the angle between the interfacial tension on either side of the central interface and the horizontal direction is the same; Figure 7 (2) and (3) in the above are progressive processes. Figure 7 (2) indicates that the liquid level rises due to the presence of the asymmetric meniscus, breaking the resting state; Figure 7 (3) in it is the final state of the capture process and the stress state during the transmission process; Figure 7 (4) is the in-situ release process of the controlled object. When the magnetically controlled microneedle swings to the opposite direction, the angle between the interfacial tension on both sides of the controlled object and the horizontal direction becomes approximately the same again, so that the magnetically controlled microneedle and the controlled object are out of control.

[0064] In the present invention, when the magnetically controlled microneedle is a magnetically controlled microneedle array, the multifunctional motion is that the controlled object is transmitted in a directional manner by the magnetically controlled microneedle array; the directional transmission is performed along the direction of the magnetically controlled microneedle array. For the magnetically controlled microneedle array, the transmission motion of the controlled object between the magnetically controlled microneedles is achieved by changing the liquid surface equilibrium state through the posture relationship of the two needles. As the posture relationship of the magnetically controlled microneedles changes, the liquid surface height will change accordingly, and a difference will appear in the liquid surface height near the two needles, and the control difference is used to achieve directional control of the controlled object. The magnetic field changes during the operation, such as Figure 5 As shown, Figure 5 The four steps (1), (2), (3) and (4) are repeated repeatedly. Figure 5 The basic process of controlling the directional transmission of an object in a magnetically controlled microneedle array formed by three magnetically controlled microneedles (from Figure 5 The directional transport includes two basic processes of capture and rotation in the control of a free single magnetically controlled microneedle.

[0065] In the present invention, the control principle of controlling the multifunctional motion of the controlled object is as follows: the control of the multifunctional motion of the controlled object by the present invention is based on the basic property of the interfacial tension effect. Due to the difference in surface energy, there is a concept of contact angle at the solid-liquid-gas / liquid three-phase interface. When the contact angle is not 90°, there is interface deformation, which manifests itself as a rise or fall in the liquid level in the vertical direction. A typical phenomenon is capillary action. Using this basic property, when other conditions remain unchanged, changing the inclination angle of the microneedle can obtain different meniscus heights on the inclined side and the opposite side, thereby achieving asymmetric differentiated control.

[0066] On the other hand, for the controlled object (i.e., multiphase particles) at the interface, there is also a meniscus. In the static state, the resultant force provided by the interfacial tension around is 0, and the particles do not move. When the meniscus provided by the magnetically controlled microneedle overlaps with the meniscus of the particle, the rising liquid level will change the morphology of the liquid surface on one side of the particle, making the interfacial tension on the particle in the plane non-zero, thereby driving the particle to follow the asymmetric meniscus.

[0067] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0068] Example 1

[0069] This embodiment provides a method for manipulating multiphase particles by regulating the meniscus by a microneedle in response to a magnetic field. The present invention uses a change in the magnetic field to change the position of a magnetically controlled microneedle, and produces a deformation of an asymmetric meniscus on a fluid interface. After the deformation of the asymmetric meniscus is obtained, the deformation of the asymmetric meniscus is used to provide a horizontal component difference of the interfacial tension. After the horizontal component difference of the interfacial tension is obtained, the present invention uses the horizontal component difference of the interfacial tension to drive a controlled object to perform a multifunctional movement, wherein the controlled object includes solid-phase particles, liquid-phase particles or gas-phase particles, and the multifunctional movement includes one or more of the controlled object being captured, rotated, transmitted and released in situ by the magnetically controlled microneedle.

[0070] The material of the magnetically controlled microneedle used in this embodiment is stainless steel. The method of generating the magnetic field relies on external magnet induction and the three-axis electromagnetic coil relies on the control of the signal generator.

[0071] In this embodiment, the method for preparing a slippery liquid-infused porous surface (SLIPS) for free single magnetically controlled microneedles includes: spin coating a polytetrafluoroethylene suspension (60wt%) onto a glass sheet (the size of the glass sheet is not required), sintering by heating at 380°C, and then injecting dimethyl silicone oil. The preparation is mainly to hold the dimethyl silicone oil to facilitate the formation of the two fluid interfaces required in this embodiment.

[0072] In this embodiment, the preparation method of the slippery liquid-infused porous surface (SLIPS) for the application of the magnetron microneedle array includes: arranging the microneedles under a parallel magnetic field, casting the surface with Ecoflex, heating at 120° C. for 30 minutes, and then injecting dimethyl silicone oil to form a functional surface.

[0073] Figure 8 This embodiment prepares a process of preparing a free single magnetically controlled microneedle to attract controlled objects of different materials, including bubbles, droplets, and nylon particles. Figure 8 The length of the scale bar is 1 mm.

[0074] Fig. 9 This is a real picture taken with a confocal microscope, showing how the interface morphology can be changed by controlling the tilt angle of a single free magnetically controlled microneedle. Fig. 9 The specific experimental process includes: mixing fluorescent dyes into Ecoflex, controlling the angle of the magnetically controlled microneedles in an inclined magnetic field and casting the dyed Ecoflex, and curing it by heating at 120°C for 30 minutes. After curing, remove the microneedles and cut out the cross section with a medical blade. Fix the cross section on the edge of the slide and take pictures facing the direction of the laser confocal microscope light source. Select different fluorescent dyes with their corresponding laser wavelengths (no specific requirements, 488nm in this experiment), and take pictures at different tilt angles α. Fig. 9 The contents of the upper and lower figures in the figure correspond to Figure 6 (2) and (3) in the figure are the results of qualitative shooting to verify the theory.

[0075] Fig.10 To control the movement of droplets by magnetically controlled microneedle arrays, Fig.10 The length of the scale bar is 1 mm. Fig.10 The magnetically controlled microneedles in the magnetically controlled microneedle array are polished stainless steel needles with a length of 2 mm. The distance between any two adjacent magnetically controlled microneedles is 4 mm. The particles are droplets dyed with aniline blue (no specific ratio requirements, no specific size requirements). The swing and rotation of the microneedles are achieved by controlling the local magnetic field, thereby realizing the directional migration of the droplets.

[0076] Fig.11 The microneedles control the droplets of different solutions to achieve continuous and staged microchemical reactions. Fig.11 The scale bar is 1 mm long. Fig.11 The specific experimental method includes: placing 10 μL of sodium bicarbonate aqueous solution, 10 μL of calcium chloride aqueous solution and a small amount of anhydrous copper sulfate powder on the SLIPS substrate. Using the magnetic field to modulate the tilted microneedle, the sodium bicarbonate solution is transported to merge with the calcium chloride solution to form a white calcium carbonate precipitate. Then, the transport reaction product contacts the anhydrous copper sulfate powder to initiate a hydration reaction.

[0077] It can be seen from the above embodiments that the present invention realizes controllable directionality, flexible and precise control of the controlled object at the fluid interface by utilizing the asymmetric meniscus generated by the tilted magnetically controlled microneedle and adjusting the height of the meniscus. Secondly, the interfacial tension effect has no special requirements on the material properties of the controlled object itself, and can achieve the capture, transfer, rotation and release of various particles such as bubbles, droplets and solid particles, significantly broadening the scope of controllable materials and the control environment, and is not limited to magnetically responsive materials. Finally, the present invention enriches the motion control mode, provides more diverse and efficient control means, greatly improves its practicality and application prospects, and is suitable for a wider range of functional materials and particle control in complex environments.

[0078] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for manipulating multiphase particles by regulating the meniscus of a magnetic field-responsive microneedle, characterized in that: The following steps are involved: The position of the magnetically controlled microneedle is changed by changing the magnetic field, so as to generate an asymmetric meniscus deformation on the fluid interface; the asymmetric meniscus deformation provides a horizontal component difference of the interfacial tension for the controlled object, and the controlled object includes solid phase particles, liquid phase particles or gas phase particles; The difference in the horizontal component of the interfacial tension is used to drive the controlled object to perform a multifunctional movement, wherein the multifunctional movement includes one or more of the controlled object being captured, rotated, transported, and released in situ.

2. The method for controlling multiphase particles by regulating meniscus with a magnetic field-responsive microneedle according to claim 1, characterized in that: The application form of the magnetically controlled microneedle includes a single magnetically controlled microneedle or a magnetically controlled microneedle array.

3. The method for controlling multiphase particles by regulating meniscus with a magnetic field-responsive microneedle according to claim 2, characterized in that: The length of the single magnetically controlled microneedle is 1 to 5 mm, and the bottom radius is 0.15 to 0.5 mm; the single magnetically controlled microneedle is a free single magnetically controlled microneedle.

4. The method for controlling multiphase particles by regulating meniscus with a magnetic field-responsive microneedle according to claim 2, characterized in that: The length of any single magnetically controlled microneedle in the magnetically controlled microneedle array is 1 to 5 mm, and the bottom radius is 0.15 to 0.5 mm; The spacing distance between any two adjacent magnetically controlled microneedles in the magnetically controlled microneedle array is 1 to 2 times the length of a single magnetically controlled microneedle.

5. The method for controlling multiphase particles by regulating meniscus with a magnetic field-responsive microneedle according to claim 2 or 3, characterized in that: The posture of the single magnetically controlled microneedle includes swinging and translation.

6. The method for controlling multiphase particles by regulating meniscus with a magnetic field-responsive microneedle according to claim 2 or 4, characterized in that: When the magnetically controlled microneedle is a magnetically controlled microneedle array, the multifunctional motion is directed transmission; the directed transmission is that the controlled object is transmitted along the arrangement direction of the magnetically controlled microneedles in the magnetically controlled microneedle array.

7. The method for controlling multiphase particles by regulating meniscus with a magnetic field-responsive microneedle according to claim 1, characterized in that: The controlled object includes bubbles, droplets, hydrogel particles or hard particles; the radius of the controlled object is greater than 0.5 mm.

8. The method for controlling multiphase particles by regulating meniscus with a magnetic field-responsive microneedle according to claim 1, characterized in that: The fluid interface includes a gas-liquid interface or a liquid-liquid interface.

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