A 4D photoresist and its preparation method and application

Abstract

The present invention belongs to the technical field of photoresists. The present invention provides a 4D photoresist and a preparation method and application thereof. The 4D photoresist provided by the present invention comprises aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivatives, a photoinitiator and a quencher, wherein the aliphatic polyurethane acrylate is used as an elastomer providing elasticity, and the acrylate-modified polyethylene glycol derivative is used as a hydrogel providing biocompatibility and hydrogen-bond-based affinity with aqueous solutions; the Young's modulus of the 4D photoresist of the present invention can be programmed in real time by laser power as the laser power increases, and the Young's modulus is lower at different laser powers, and the 4D photoresist has good compliance; the 4D photoresist of the present invention can be integrated into a soft micro-mechanical structure for performing biomedical tasks, such as studying tissue and cell biomechanics, and transporting and releasing cells or therapeutic cargoes, etc., and has a wide range of applications.

Description

Technical Field

[0001] The present invention relates to the technical field of photoresists, and in particular to a 4D photoresist and a preparation method and application thereof. Background Art

[0002] Micro-spring assemblies are essential for soft micromechanical structures to perform biomedical tasks, such as assessing tissue and cellular biomechanics, and carrying and releasing cells or therapeutic cargoes. Due to the lack of applicable micro-spring systems, it is difficult for artificial micromachines to mimic the complex functions of bacteria or sperm using their elastic pili or flagella to sense piconewton-level forces and achieve self-propulsion. In addition, the fabrication of microsprings that work under biological conditions is challenging. Given the weak forces that cells can withstand and generate, spring-based micromachines that interact with them must be stable in aqueous solutions and have tunable compliance that is sensitive to piconewton-level forces, as well as low Young's modulus and high yield strain. Incorporating springs into such customized micromachines faces the challenge of high-resolution integrated manufacturing of rigid and flexible components with different elasticities.

[0003] Two-photon (or multi-photon) lithography can achieve four-dimensional (4D) nanofabrication of complex micromachines. The 4D lithography concept combines three-dimensional (3D) manufacturing processes with dynamic material regulation, providing feasibility for the preparation of micro-spring components with more complex functions. Compared with static objects created by 3D lithography, 4D lithography allows 3D lithographic structures to change their functions over time in response to external stimuli such as temperature, light, and water. However, the application of 4D nanofabrication is greatly limited due to the low compliance (in the micron and micronewton range) of traditional material photoresist materials (e.g., IP-DIP photoresist) or dependence on organic solvents. Therefore, it is necessary to develop elastic photoresists compatible with 4D nanofabrication. Summary of the invention

[0004] In order to solve the problem in the prior art that photoresist materials have low flexibility or are dependent on organic solvents, which limits their application in 4D nanofabrication, the present invention provides a 4D photoresist and a preparation method and application thereof.

[0005] In a first aspect, the present invention provides a 4D photoresist comprising aliphatic polyurethane acrylate, an acrylate-modified polyethylene glycol derivative, a photoinitiator and a quencher.

[0006] Preferably, the acrylate-modified polyethylene glycol derivative includes at least one of poly(ethylene glycol) methacrylate 360, poly(ethylene glycol) methacrylate 480, polyethylene glycol diacrylate 700, polyethylene glycol diacrylate 250 and polyethylene glycol diacrylate 10000;

[0007] And / or, the photoinitiator includes at least one of Irgacure 369, Irgacure 397, Irgacure 819, and Irgacure 651;

[0008] And / or, the quencher includes at least one of 2,2,6,6-tetramethylpiperidin-1-oxyl, tris(2-hydroxypropyl)amine, tetrakis(2-hydroxypropyl)ethylenediamine and methyl methacrylate.

[0009] Preferably, the mass ratio of the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator and the quencher is (40-80):(20-50):(1-4):(0.01-2).

[0010] Preferably, the mass ratio of the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator and the quencher is 52:44:2.8:1.2.

[0011] Preferably, superparamagnetic nanoparticles are also included.

[0012] Preferably, the particle size of the superparamagnetic nanoparticles is 5 to 100 nm;

[0013] And / or, the superparamagnetic nanoparticles include at least one of Fe3O4, Fe2O3, modified Fe3O4, and modified Fe2O3;

[0014] And / or, the mass ratio of the aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, quencher, and superparamagnetic nanoparticles is (40-80):(20-50):(1-4):(0.01-2):(2-15).

[0015] Preferably, the mass ratio of the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator, the quencher, and the superparamagnetic nanoparticles is (40-80):(20-50):(1-4):(0.01-2):6.

[0016] In a second aspect, the present invention further provides a method for preparing the 4D photoresist, comprising the following steps:

[0017] Stirring and mixing the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator, the quencher, and the optional superparamagnetic nanoparticles to obtain a mixture;

[0018] The mixture was bubbled with nitrogen and then vacuumed for degassing to obtain a 4D photoresist.

[0019] Preferably, in the step of stirring and mixing the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator, the quencher, and the optional superparamagnetic nanoparticles, the stirring time is 24 to 48 hours;

[0020] And / or, in the step of bubbling the mixture with nitrogen and then vacuuming it for degassing, the nitrogen bubbling time is 20 to 40 minutes and the vacuuming time is 20 to 40 minutes.

[0021] In a third aspect, the present invention further provides an application of the 4D photoresist or the 4D photoresist prepared by the preparation method in the preparation of soft micromechanical devices.

[0022] The 4D photoresist and its preparation method and application of the present invention have the following beneficial effects compared with the prior art:

[0023] 1. The 4D photoresist of the present invention does not rely on organic solvents during its preparation process. It contains an elastomer (aliphatic polyurethane acrylate) that provides elasticity, and a hydrogel (acrylate-modified polyethylene glycol derivative) that provides biocompatibility and hydrogen-bond-based affinity with aqueous solutions. The Young's modulus of the 4D photoresist can be programmed in real time by the laser power as the laser power increases. The 4D photoresist of the present invention has a lower Young's modulus at different laser powers, that is, it has good flexibility.

[0024] 2. The 4D photoresist of the present invention can be integrated into soft micromechanical structures to perform biomedical tasks, such as studying tissue and cell biomechanics, and transporting and releasing cells or therapeutic cargoes, etc., and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a schematic structural diagram of the 4D photoresist of the present invention;

[0027] Figure 2 A physical picture of the 4D photoresist prepared in Example 1;

[0028] Figure 3 An optical image of the AFM measurement process of the 4D photoresist prepared in Example 3;

[0029] Figure 4A graph showing the change of Young's modulus of 4D photoresists prepared in Example 1, Example 6 and Comparative Example 1 under different laser powers;

[0030] Figure 5 A microscope image of the lithographic structure of the 4D photoresist prepared in Example 4 under a laser power variation of 4 to 7.75 mW;

[0031] Figure 6 The scanning electron microscope image of the lithographic structure of the 4D photoresist prepared in Example 4 under continuous laser power variation;

[0032] Figure 7 This is a deformation test effect diagram of the 4D photoresist obtained in Example 4 and Example 6. DETAILED DESCRIPTION

[0033] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. In addition, in the description of the present application, the term "including" means "including but not limited to". Various embodiments of the present invention may be in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the present invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the numbered ranges, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0035] An embodiment of the present application provides a 4D photoresist, including aliphatic polyurethane acrylate, an acrylate-modified polyethylene glycol derivative, a photoinitiator, and a quencher.

[0036] The 4D photoresist of the present invention comprises aliphatic polyurethane acrylate as an elastomer providing elasticity, and an acrylate-modified polyethylene glycol derivative as a hydrogel providing biocompatibility and hydrogen-bond-based affinity with aqueous solutions; the 4D photoresist of the present invention is a four-dimensional (4D) photoresist with elastic modulus as the fourth programming degree of freedom, that is, a new dimension of the change of the Young's modulus of the photoresist under laser power response is added on the basis of three-dimensional photolithography; the 4D photoresist of the present invention is a 4D photoresist, and its preparation process does not rely on organic solvents, and it contains an elastomer providing elasticity (aliphatic polyurethane acrylate), and a hydrogel providing biocompatibility and hydrogen-bond-based affinity with aqueous solutions (acrylate-modified polyethylene glycol derivative), and the Young's modulus of the 4D photoresist can be programmed in real time through laser power as the laser power increases; the 4D photoresist of the present invention can be integrated into soft micromechanical structures for performing biomedical tasks, such as studying tissue and cell biomechanics, and transporting and releasing cells or therapeutic cargoes, etc., and has a wide range of applications.

[0037] In some embodiments, the acrylate-modified polyethylene glycol derivative includes at least one of poly(ethylene glycol) methacrylate 360, poly(ethylene glycol) methacrylate 480, polyethylene glycol diacrylate 700, polyethylene glycol diacrylate 250, and polyethylene glycol diacrylate 10000.

[0038] Specifically, in the above embodiments, poly(ethylene glycol) methacrylate 360 ​​and poly(ethylene glycol) methacrylate 480, wherein 360 and 480 respectively represent the average molecular weight of poly(ethylene glycol) methacrylate; polyethylene glycol diacrylate 700, polyethylene glycol diacrylate 250 and polyethylene glycol diacrylate 10000, wherein 700, 250 and 10000 respectively represent the average molecular weight of polyethylene glycol diacrylate.

[0039] In some embodiments, aliphatic polyurethane acrylate is a highly polymerized macromolecular compound, which is generated by the addition reaction of acrylate and polyurethane, and its molecular structure contains multiple acrylate and polyurethane units, which are linked together by covalent bonds to form a macromolecule with a complex three-dimensional structure. This special molecular structure makes aliphatic polyurethane acrylate have excellent physical and chemical properties, such as high strength, high toughness, high wear resistance, high chemical corrosion resistance, etc. For example, aliphatic polyurethane acrylate can be BASF Laromer® UA 9089 polyurethane acrylate, or DSM aliphatic polyurethane acrylate with model number Agisyn 530.

[0040] In some embodiments, the photoinitiator includes at least one of BASF photoinitiators Irgacure 369, Irgacure 397, Irgacure 819, and Irgacure 651.

[0041] In some embodiments, the quencher includes at least one of 2,2,6,6-tetramethylpiperidin-1-oxyl, tris(2-hydroxypropyl)amine, tetrakis(2-hydroxypropyl)ethylenediamine, and methyl methacrylate.

[0042] Preferably, in some embodiments, the quencher is a mixed quencher of 2,2,6,6-tetramethylpiperidine-1-oxyl and methyl methacrylate, and the mass ratio of 2,2,6,6-tetramethylpiperidine-1-oxyl to methyl methacrylate is 1:1.

[0043] Specifically, 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO), the molecular formula is C9H 18 NO, also known as 2,2,6,6-tetramethylpiperidinoxide, 2,2,6,6-tetramethyl-1-piperidone; tri(2-hydroxypropyl)amine, also known as triisopropanolamine, molecular formula: C9H 21 NO3; Tetrakis(2-hydroxypropyl)ethylenediamine, also known as tetrahydroxypropylethylenediamine, has the molecular formula: C 14 H 32 N2O4; Methyl methacrylate, also known as MMA, abbreviated as methyl methacrylate, has the molecular formula: C5H8O2.

[0044] In some embodiments, the mass ratio of aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator and quencher is (40-80):(20-50):(1-4):(0.01-2).

[0045] In some embodiments, the mass ratio of aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, and quencher is 52:44:2.8:1.2.

[0046] In some embodiments, superparamagnetic nanoparticles are further included. Superparamagnetic nanoparticles are added to the 4D photoresist to provide magnetic force or magnetic moment.

[0047] In some embodiments, the superparamagnetic nanoparticles have a particle size of 5 to 100 nm.

[0048] In some embodiments, the superparamagnetic nanoparticles include at least one of Fe3O4, Fe2O3, modified Fe3O4, and modified Fe2O3.

[0049] In some embodiments, the mass ratio of aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, quencher, and superparamagnetic nanoparticles is (40-80):(20-50):(1-4):(0.01-2):(2-15).

[0050] In some embodiments, the mass ratio of aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, quencher, and superparamagnetic nanoparticles is (40-80):(20-50):(1-4):(0.01-2):6.

[0051] The 4D photoresist of the present invention can be programmed in the x, y, z, and e directions, wherein x, y, and z are three-dimensional spatial coordinates, and e is Young's modulus, which can be adjusted in real time within the nanometer space range by laser power, thus adding a new dimension of the elastic modulus of the photoresist changing under laser power response on the basis of three-dimensional lithography.

[0052] For further reference, Figure 1 As shown, it shows a schematic structural diagram of the 4D photoresist of the present invention; during the photolithography process, aliphatic polyurethane acrylate and acrylate-modified polyethylene glycol derivatives form a 4D photoresist with a cross-linked network structure under the action of a photoinitiator; the elastic modulus of the 4D photoresist can be adjusted by laser power, for example, the elastic modulus varies between 1 and 500 MPa, thereby achieving a new dimension of the elastic modulus of the photoresist changing under laser power response on the basis of three-dimensional photolithography.

[0053] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned 4D photoresist, comprising the following steps:

[0054] S1, stirring and mixing aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, quencher, and optional superparamagnetic nanoparticles to obtain a mixture;

[0055] S2. Bubble the mixture in S1 with nitrogen and then evacuate it for degassing to obtain 4D photoresist.

[0056] Specifically, the optional superparamagnetic nanoparticles in the above step S1 mean that superparamagnetic nanoparticles may be added or not.

[0057] In some embodiments, in the step of stirring and mixing the aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, quencher, and optional superparamagnetic nanoparticles, the stirring time is 24 to 48 hours.

[0058] In some embodiments, in the step of bubbling the mixture in S1 with nitrogen and then evacuating to degas, the nitrogen bubbling time is 20 to 40 min, and the vacuuming time is 20 to 40 min.

[0059] Based on the same inventive concept, the present invention also provides an application of the above-mentioned 4D photoresist or the 4D photoresist prepared by the above-mentioned preparation method in the preparation of soft micromechanical devices.

[0060] The 4D photoresist of the present invention can be integrated into soft micromechanical devices to perform biomedical tasks, such as studying tissue and cell biomechanics, and transporting and releasing cells or therapeutic cargoes, etc., and has a wide range of applications.

[0061] The following further describes the 4D photoresist of the present invention and its preparation method and application with specific examples. This section further describes the content of the present invention in conjunction with specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0062] In the following examples, the aliphatic polyurethane acrylate is BASF Laromer® UA 9089 aliphatic polyurethane acrylate, and poly(ethylene glycol) methacrylate 360 ​​and polyethylene glycol diacrylate 700 are purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0063] Example 1

[0064] This embodiment provides a 4D photoresist, including aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, a photoinitiator and a quencher;

[0065] Among them, the mass ratio of aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator and quencher is 47.2:49.8:1.3:1.2;

[0066] The acrylate-modified polyethylene glycol derivative is polyethylene glycol diacrylate 700;

[0067] The photoinitiator was BASF photoinitiator Irgacure 369;

[0068] The quencher is a mixed quencher of 2,2,6,6-tetramethylpiperidine-1-oxyl and methyl methacrylate, and the mass ratio of 2,2,6,6-tetramethylpiperidine-1-oxyl to methyl methacrylate is 1:1.

[0069] The preparation method of the above 4D photoresist comprises the following steps:

[0070] S1, stirring and mixing aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, and quencher for 24 hours to obtain a mixture;

[0071] S2. The mixture in S1 was bubbled with nitrogen for 20 minutes, and then vacuumed for 20 minutes for degassing to obtain a 4D photoresist.

[0072] Example 2

[0073] This embodiment provides a 4D photoresist, including aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, a photoinitiator and a quencher;

[0074] The mass ratio of aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator and quencher is 52:44:2.8:1.2;

[0075] The acrylate-modified polyethylene glycol derivative is polyethylene glycol diacrylate 700;

[0076] The photoinitiator was BASF photoinitiator Irgacure 369;

[0077] The quencher is a mixed quencher of 2,2,6,6-tetramethylpiperidine-1-oxyl and methyl methacrylate, and the mass ratio of 2,2,6,6-tetramethylpiperidine-1-oxyl to methyl methacrylate is 1:1.

[0078] The preparation method of the above 4D photoresist comprises the following steps:

[0079] S1, stirring and mixing aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, and quencher for 48 hours to obtain a mixture;

[0080] S2. The mixture in S1 was bubbled with nitrogen for 40 minutes, and then vacuumed for 40 minutes for degassing to obtain a 4D photoresist.

[0081] Example 3

[0082] This embodiment provides a 4D photoresist, including aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, a photoinitiator and a quencher;

[0083] Among them, the mass ratio of aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator and quencher is 47.2:49.8:1.3:1.2;

[0084] The acrylate-modified polyethylene glycol derivative is polyethylene glycol diacrylate 700;

[0085] The photoinitiator was BASF photoinitiator Irgacure 651;

[0086] The quencher is a mixed quencher of 2,2,6,6-tetramethylpiperidine-1-oxyl and methyl methacrylate, and the mass ratio of 2,2,6,6-tetramethylpiperidine-1-oxyl to methyl methacrylate is 1:1.

[0087] The preparation method of the above 4D photoresist comprises the following steps:

[0088] S1, stirring and mixing aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, and quencher for 36 hours to obtain a mixture;

[0089] S2. The mixture in S1 was bubbled with nitrogen for 30 minutes, and then vacuumed for 30 minutes for degassing to obtain a 4D photoresist.

[0090] Example 4

[0091] This embodiment provides a 4D photoresist, including aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, a photoinitiator and a quencher;

[0092] The mass ratio of aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator and quencher is 52:44:2.8:1.2;

[0093] The acrylate-modified polyethylene glycol derivative is poly(ethylene glycol) methacrylate 360;

[0094] The photoinitiator was BASF photoinitiator Irgacure 651;

[0095] The quencher is a mixed quencher of 2,2,6,6-tetramethylpiperidine-1-oxyl and methyl methacrylate, and the mass ratio of 2,2,6,6-tetramethylpiperidine-1-oxyl to methyl methacrylate is 1:1.

[0096] The preparation method of the above 4D photoresist comprises the following steps:

[0097] S1, stirring and mixing aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, and quencher for 36 hours to obtain a mixture;

[0098] S2. The mixture in S1 was bubbled with nitrogen for 35 minutes, and then vacuumed for 30 minutes for degassing to obtain a 4D photoresist.

[0099] Example 5

[0100] The 4D photoresist prepared in the above Examples 1 to 4 was tested for its mechanical response capability under an atomic force microscope (AFM) probe, and then the Young's modulus (e) of the photoresist was calculated. The test results are shown in Table 1 below.

[0101] Table 1 - Young's modulus of 4D photoresists prepared in different embodiments at different laser powers

[0102]

[0103] It can be seen from the above table that the 4D photoresist of the present invention has a lower Young's modulus under different laser powers, that is, it has good flexibility. From the formulation, the Young's modulus of the photoresist can be further reduced by increasing the content of the photoinitiator.

[0104] Example 6

[0105] This embodiment provides a 4D photoresist, including aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivatives, a photoinitiator, a quencher, and superparamagnetic nanoparticles;

[0106] The mass ratio of aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, quencher and superparamagnetic nanoparticles is 49:41:2.8:1.2:6;

[0107] The acrylate-modified polyethylene glycol derivative is poly(ethylene glycol) methacrylate 360;

[0108] The photoinitiator was BASF photoinitiator Irgacure 369;

[0109] The quencher is a mixed quencher of 2,2,6,6-tetramethylpiperidin-1-oxyl and methyl methacrylate, and the mass ratio of 2,2,6,6-tetramethylpiperidin-1-oxyl to methyl methacrylate is 1:1;

[0110] The average particle size of the superparamagnetic nanoparticles is 50 nm, and the superparamagnetic nanoparticles are Fe3O4.

[0111] The preparation method of the above 4D photoresist comprises the following steps:

[0112] S1, stirring and mixing aliphatic polyurethane acrylate, acrylate-modified polyethylene glycol derivative, photoinitiator, quencher, and superparamagnetic nanoparticles for 36 hours to obtain a mixture;

[0113] S2. The mixture in S1 was bubbled with nitrogen for 40 min, and then vacuumed for 40 min for degassing to obtain a 4D photoresist.

[0114] Comparative Example 1

[0115] This comparative example provides a 4D photoresist, comprising polyurethane acrylate oligomer, acrylate-modified polyethylene glycol derivative, photoinitiator and quencher, wherein: the polyurethane acrylate oligomer is GC810 produced by Smet Chemical Industry Co., Ltd.

[0116] The mass ratio of polyurethane acrylate oligomer, acrylate-modified polyethylene glycol derivative, photoinitiator and quencher is 70:28.4:1.5:0.1;

[0117] The acrylate-modified polyethylene glycol derivative is polyethylene glycol diacrylate 700;

[0118] The photoinitiator is 1-(4-(2-(dimethylamino)ethoxy)phenyl)-2-phenyl-1-butanone;

[0119] The quencher is a mixed quencher of 2,2,6,6-tetramethylpiperidin-1-oxyl and methyl methacrylate, and the mass ratio of 2,2,6,6-tetramethylpiperidin-1-oxyl to methyl methacrylate is 1:1;

[0120] The polyurethane acrylate oligomer used is ETERCURE6130B-80 produced by Changxing.

[0121] The preparation method of the above 4D photoresist comprises the following steps:

[0122] S1, stirring and mixing a polyurethane acrylate oligomer, an acrylate-modified polyethylene glycol derivative, a photoinitiator, and a quencher for 24 hours to obtain a mixture;

[0123] S2. The mixture in S1 was bubbled with nitrogen for 20 min, and then vacuumed for 20 min for degassing to obtain a 4D photoresist.

[0124] Figure 2 This is a photograph of the 4D photoresist prepared in Example 1 with elastic modulus as the fourth programming degree of freedom.

[0125] from Figure 2 As can be seen, the photoresist was successfully prepared and can be stored (30~50 days).

[0126] Mechanical distribution test of photoresist: The optical image of the AFM measurement process of the 4D photoresist obtained in Example 3 is shown in Figure 3 .

[0127] from Figure 3 It can be seen that the mechanical response ability of the photoresist is tested under the atomic force microscope (AFM) probe, and then the elastic modulus of the photoresist is calculated.

[0128] Young's modulus test of photoresist with different components at different laser powers: Figure 4 The graph is a graph showing the change in Young's modulus of the 4D photoresists prepared in Example 1, Example 6 and Comparative Example 1 under different laser powers.

[0129] from Figure 4 It can be seen that with the increase of laser power, the Young's modulus of the 4D photoresists prepared in Examples 1, 6 and Comparative Example 1 increases, which indicates that the 4D photoresist of the present invention and the 4D photoresist in Comparative Example 1 have a Young's modulus that can be adjusted in real time within the nanometer space range by laser power; in addition, under the same laser power, the Young's modulus of the 4D photoresist prepared in Comparative Example 1 is greater than that of the 4D photoresist prepared in Examples 1 and 6, which shows that the 4D photoresist prepared by the present invention has a lower Young's modulus than that of Comparative Example 1, that is, it has good flexibility.

[0130] Depend on Figure 4 It can be seen that as the laser power increases from 5.5 mW to 7.5 mW, the Young's modulus of the photoresist in Examples 1 and 6 increases by more than 122 times, indicating that the elastic photoresist is suitable for 4D lithography and the elasticity of programmable 4D lithography can be widely programmed by locally programming the laser power.

[0131] The effect of different laser powers on 4D lithography structure: Microscope images of the lithography structure of the 4D photoresist prepared in Example 4 under laser power variation of 4~7.75 mW are shown in Figure 2. Figure 5 shown. Figure 5 Laser Power represents the laser power (mW), and e represents the Young's modulus (Mpa). Figure 5 It can be seen that the photoresist printed with a laser power as low as 4 mW has a clear and complete structure.

[0132] The effect of continuously changing laser power on 4D lithography structure: The scanning electron microscope image of the lithography structure of the 4D photoresist prepared in Example 4 under continuous laser power change is as follows: Figure 6 .Depend on Figure 6 It can be seen that in the same 4D lithographic structure, the Young's modulus of the lithographic structure can be continuously programmed by laser power.

[0133] Deformation test of photoresist: Deformation test of 4D photoresist prepared in Example 4 and Example 6 (cycle test twice) Figure 7 .Depend on Figure 7It can be seen that the magnetic 4D photoresist prepared in Example 6 is used as the clamping part of the micro-tweezers to respond to the external magnetic field, and the 4D photoresist prepared in Example 4 is connected as a spiral spring. Under the action of the external magnetic field, the micro-tweezers can switch between the clamping state (0 mT) and the open state (10 mT), indicating that the 4D photolithography photoresist has been successfully integrated into the soft micromechanical device.

[0134] It can be understood that the technical features of the above-described embodiments can be arbitrarily combined. In order to make the description concise, not all possible combinations of the technical features in the above-described 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.

[0135] The above are only preferred embodiments of the present application, and only specifically describe the technical principles of the present application. These descriptions are only for explaining the principles of the present application and cannot be interpreted as limiting the scope of protection of the present application in any way. Based on the explanation here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application, and other specific implementation methods of the present application that can be associated with the technicians in this field without creative work, should be included in the scope of protection of the present application.

Claims

1. A 4D photoresist, It is characterized in that Including aliphatic polyurethane acrylate, acrylate modified polyethylene glycol derivative, photoinitiator and quencher; The acrylate-modified polyethylene glycol derivative includes at least one of polyethylene glycol diacrylate 700 and poly(ethylene glycol) methacrylate 360; The photoinitiator includes at least one of Irgacure 369 and Irgacure 651; The quencher is a mixed quencher of 2,2,6,6-tetramethylpiperidin-1-oxyl and methyl methacrylate, and the mass ratio of 2,2,6,6-tetramethylpiperidin-1-oxyl to methyl methacrylate is 1:1; The mass ratio of the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator and the quencher is (47.2-52):(44-49.8):(1.3-2.8):1.2; The preparation method of the 4D photoresist comprises the following steps: The aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator, and the quencher are stirred and mixed to obtain a mixture; The mixture was bubbled with nitrogen and then vacuumed for degassing to obtain a 4D photoresist.

2. The 4D photoresist according to claim 1, It is characterized in that The mass ratio of the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator and the quencher is 52:44:2.8:1.

2.

3. The 4D photoresist according to any one of claims 1 to 2, It is characterized in that Also included are superparamagnetic nanoparticles.

4. The 4D photoresist according to claim 3, It is characterized in that The particle size of the superparamagnetic nanoparticles is 5 to 100 nm; And / or, the superparamagnetic nanoparticles include Fe 3 O 4 , Fe 2 O 3 , modified Fe 3 O 4 , modified Fe 2 O 3 At least one of .

5. The 4D photoresist according to claim 4, It is characterized in that The mass ratio of the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator, the quencher, and the superparamagnetic nanoparticles is 49:41:2.8:1.2:

6.

6. A method for preparing a 4D photoresist as claimed in any one of claims 1 to 5, It is characterized in that The following steps are involved: Stirring and mixing the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator, the quencher, and the optional superparamagnetic nanoparticles to obtain a mixture; The mixture was bubbled with nitrogen and then vacuumed for degassing to obtain a 4D photoresist.

7. The method for preparing the 4D photoresist according to claim 6, It is characterized in that In the step of stirring and mixing the aliphatic polyurethane acrylate, the acrylate-modified polyethylene glycol derivative, the photoinitiator, the quencher, and the optional superparamagnetic nanoparticles, the stirring time is 24 to 48 hours; And / or, in the step of bubbling the mixture with nitrogen and then vacuuming it for degassing, the nitrogen bubbling time is 20 to 40 minutes and the vacuuming time is 20 to 40 minutes.

8. Use of the 4D photoresist according to any one of claims 1 to 5 or the 4D photoresist prepared by the preparation method according to any one of claims 6 to 7 in the preparation of soft micromechanical devices.

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