A multimodal deformation sensing hydrogel and preparation method and application thereof

Abstract

The present application relates to a kind of multimodal deformation sensing hydrogel and its preparation method and application, the sensing hydrogel includes the following components: alginic acid hydrogel and hyaluronic acid methacrylic acid;Two long ends of alginic acid hydrogel are clamped, dry, hyaluronic acid methacrylic acid is dissolved in water, and is polymerized into shape with alginic acid hydrogel, obtain multimodal deformation sensing hydrogel.Compared with prior art, the present application has excellent comprehensive mechanical properties and electrical conductivity, has three-dimensional strain detection range, good signal repeatability and high response sensitivity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of gel production, and relates to a multi-modal deformation sensing hydrogel as well as a preparation method and application thereof. BACKGROUND

[0002] In recent years, flexible electronic products have attracted extensive attention due to their ability to accurately record mechanical signals and monitor health and motion states in real time. Hydrogels are considered as one of the promising materials for developing intelligent flexible wearable devices due to their simple preparation process, good biocompatibility, environmental friendliness and electrical conductivity. However, the isotropic structural characteristics of hydrogels limit their application potential in identifying complex multi-strain environments. Nature provides a wealth of inspiration for the development of flexible wearable devices. Many soft tissues of living organisms, such as skin and muscle, have highly ordered anisotropic microstructures, can actively perceive and manage their own movements, and exhibit high information response ability and contraction ability. At present, many hydrogel sensors that simulate the anisotropic structure of natural materials have been developed, which have been proven to effectively improve the sensing properties of hydrogels.

[0003] 3D highly ordered structure improves the strength and mechanical fatigue resistance of hydrogels, and the directional transfer of ions is enhanced, achieving precise and wide-range mechanical response. More importantly, the anisotropic morphology and multi-level structure lead to the asymmetry and direction selectivity of the sensing performance of hydrogels, exhibiting super-strong wide-range response ability and high sensitivity in the direction parallel to the orientation direction, and rapid response to mechanical changes in the direction perpendicular to the orientation direction. This to some extent solves the defect that traditional flexible sensors can only output single signal, but the effectiveness of flexible sensors is still subject to many challenges, including the limitation of one-way deformation and the limitation of two-dimensional mechanical response range. In fact, human behavior exhibits complex strain patterns, such as wrist bending, walking and other behaviors, in which tensile strain and compressive strain often interweave or occur simultaneously, and flexible sensors need to have the ability to respond to three-dimensional mechanical changes to achieve accurate capture of biological signals.

[0004] Therefore, it is of great significance to develop a hydrogel material with a structure close to human tissues, good mechanical properties and the ability to sensitively and stably respond to three-dimensional mechanical stimuli.

[0005] Patent CN118206799A discloses a preparation method of anisotropic hydrogel containing porous open channels. Natural polymer sodium alginate and silver nanowires are induced to form a long-range ordered layered structure by bidirectional freezing, and a poly(N-isopropyl acrylamide) hydrogel doped with carbon nanotubes is formed in the anisotropic layered framework by using a one-way freezing assisted two-stage in-situ polymerization. Although the patent uses anisotropic structure, the anisotropic layered structure is composed of aerogel materials, which has poor mechanical strength and flexibility. Although the patent forms a honeycomb-like pore by one-way freezing assisted method, the pore does not have anisotropy, and its size is difficult to control.

[0006] Patent CN116333379A discloses a multifunctional ionic hydrogel, a strain sensor and a flexible all-solid-state supercapacitor, a preparation method and application thereof. The preparation steps include: dissolving trehalose in deionized water and stirring to prepare a uniform trehalose solution; adding anhydrous lithium chloride to the trehalose solution and stirring to prepare a lithium chloride / trehalose mixed solution; taking the lithium chloride / trehalose mixed solution, adding acrylamide, acrylic acid, N,N'-methylene bisacrylamide and 2-hydroxy-4'- (2-hydroxyethoxy)-2-methyl benzophenone to the mixed solution, and stirring vigorously until a transparent and uniform solution is formed; pouring the mixed solution into a silica gel mold, and then polymerizing under a UV light lamp to form an ionic hydrogel. However, the preparation method of the patent is simple and cannot customize the structure of the hydrogel; the photopolymerization method used in the patent requires a large amount of initiator, which increases the toxicity of the hydrogel and poses a potential risk in the application of the hydrogel in wearable smart devices; at the same time, the sensing characteristics of the hydrogel of the patent are only reflected in the tensile strain, and the response sensitivity is low in a small strain range.

[0007] Patent CN113461974A discloses a gas-responsive surface-lubricating hydrogel and a preparation method thereof. The method combines a covalent polymer network and a gas-responsive supramolecular network system, wherein the covalent polymer network skeleton can provide a certain mechanical basis, and has a porous structure, which is beneficial to the movement of the supramolecular system in the three-dimensional network; at the same time, the gas-responsive supramolecular component can undergo reversible gel-sol transition under the action of carbon dioxide and nitrogen. However, the preparation method of the methacrylated hyaluronic acid in the patent is complex, the reaction requirements are high, the cost is high, and impurities may be introduced into the product; and the methacrylated hyaluronic acid in the patent is used as a crosslinking agent to form an interpenetrating network covalent skeleton with a single network hydrogel, which has limited improvement on the mechanical properties. SUMMARY

[0008] The present application aims to overcome at least one of the above-mentioned defects of the prior art, and provides a multimodal deformation sensing hydrogel, a preparation method and application thereof.

[0009] The object of the present application can be achieved by the following technical solutions:

[0010] One of the technical solutions of the present application is to provide a multimodal deformation sensing hydrogel, which comprises the following components by weight:

[0011] 1-3 parts of alginate hydrogel and 1-3 parts of hyaluronic acid methacrylate;

[0012] The two long ends of the alginate hydrogel are clamped and dried, the hyaluronic acid methacrylate is dissolved in water, and the alginate hydrogel is polymerized to obtain a multimodal deformation sensing hydrogel.

[0013] Further, the alginate hydrogel is placed in air for drying, the drying temperature is 10-40℃, and the time is 3-6h.

[0014] Further, the hyaluronic acid methacrylate and the alginate hydrogel are polymerized under anaerobic and thermal initiation conditions, the polymerization temperature is 40-60℃, and the time is 3-6h.

[0015] One of the technical solutions of the present application is to provide a preparation method of the multimodal deformation sensing hydrogel, which comprises the following steps:

[0016] S1, sodium alginate is dissolved in water to obtain a sodium alginate solution, the sodium alginate solution is poured into a mold, a metal ion solution is added for reaction to obtain an alginate hydrogel, the two long ends of the alginate hydrogel are clamped and dried, and a self-templated hierarchical structure with high alignment is created by inducing spontaneous mechanical signals;

[0017] S2, hyaluronic acid is dissolved in water, glycidyl methacrylate, triethylamine and tetrabutylammonium bromide are added for reaction to obtain hyaluronic acid methacrylate;

[0018] S3, the hyaluronic acid methacrylate is dissolved in water, a crosslinking agent and an initiator are mixed, the mixed solution is injected into a mold, and the alginate hydrogel is polymerized to form a mold, under the action of an oxidation-reduction initiation system, the hyaluronic acid methacrylate molecules are crosslinked with each other through a free radical reaction, a fiber structure is used as a template to induce the formation of oriented pores, and the hyaluronic acid methacrylate is tightly combined with the alginate hydrogel through hydrogen bonds to obtain a multimodal deformation sensing hydrogel.

[0019] Further, the mass / volume ratio of sodium alginate to water in step S1 is (1-2 g):(25-30 mL),

[0020] The metal ion solution is selected from one or more of a calcium chloride solution, a zinc chloride solution, and a barium chloride solution, and the concentration of the metal ion solution is 0.05-0.1 g / mL,

[0021] The volume ratio of the sodium alginate solution to the metal ion solution is (1-2):(1-3).

[0022] Further, the temperature for dissolving in step S1 is 10-40°C, and the time is 8-12 h,

[0023] The temperature for the reaction is 10-40°C, and the time is 3-6 h.

[0024] Further, the mass / volume ratio of hyaluronic acid to water in step S2 is (1-3 g):(50-60 mL),

[0025] The mass / volume ratio of hyaluronic acid, glycidyl methacrylate, triethylamine, and tetrabutylammonium bromide is (45-50 g):(1-8 mL):(1-8 mL):(1-8 g).

[0026] Further, the temperature for dissolving in step S2 is 10-40°C, and the time is 3-6 h,

[0027] The temperature for the reaction is 40-60°C, and the time is 1-4 h.

[0028] As a preferred technical solution, after the reaction in step S2, the solution after the reaction is precipitated, washed, and freeze-dried after being cooled to room temperature.

[0029] As a preferred technical solution, the precipitation and washing are performed in acetone.

[0030] As a preferred technical solution, the temperature for freeze-drying is -110 to -90°C, and the time is 12-24 h.

[0031] Further, the mass / volume ratio of hyaluronic acid methacrylate to water in step S3 is (0.02-0.04 g):1 mL,

[0032] The crosslinking agent is selected from one or more of polyethylene glycol bisacrylate, N,N-methylene bisacrylamide, cyclotriene, and triallyl isocyanurate, the initiator is selected from one or more of ammonium persulfate, potassium persulfate, 2-hydroxy-2-methylbenzophenone, and α-ketoglutaric acid, and the mass ratio of hyaluronic acid methacrylate, the crosslinking agent, and the initiator is 1:(0.001-0.002):(0.002-0.003),

[0033] The temperature for dissolving is 10-40 DEG C, and the time is 1-2 hours,

[0034] The temperature for mixing is 10-40 DEG C, and the time is 10-20 minutes.

[0035] One of the technical solutions of the present application is to provide the application of the multi-modal deformation sensing hydrogel.

[0036] Compared with the prior art, the present application has the following beneficial effects:

[0037] (1) The present application induces spontaneous mechanical signals to create a hydrogel with a highly aligned self-templated hierarchical structure; the long ends of the alginic acid hydrogel are clamped and fixed using a bracket, and are dried in air; the mechanical signals make the ionic interaction of the alginic acid hydrogel be sacrificed, and the polymer chains are arranged along the stress direction to form a layered fiber structure; at the same time, under the action of the redox initiation system, the hyaluronic acid methacrylate is crosslinked with each other through a free radical reaction to induce the formation of oriented pores with the fiber structure as a template; inspired by the surrounding nerves with a multi-layer ordered structure and impulse conduction by ionic signals, the present application innovatively prepares a hydrogel with a multi-layer sandwich structure composed of anisotropic fibers-pores-fibers, and the preparation method is simple and effective, low in cost, and has the prospect of industrial implementation;

[0038] (2) The sensing hydrogel prepared by the present application has excellent comprehensive mechanical properties and conductive properties, and lays a good foundation for the development of wearable smart sensors, and has great potential in flexible electronic applications such as sports science and health diagnosis;

[0039] (3) The preparation process adopted by the present application obtains a multi-modal deformation sensing hydrogel with a high anisotropic structure, a three-dimensional strain detection range, good signal repeatability and high response sensitivity, and can be used to prepare a multifunctional system for sensing three-dimensional mechanical changes and accurately identifying complex behavior patterns, and has wide practical value. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The nuclear magnetic resonance spectrum of hyaluronic acid and hyaluronic acid methacrylate in Example 1 of the present application is shown in the figure;

[0041] Figure 2 The total reflection infrared absorption spectrum (ATR-FTIR) of the calcium alginate hydrogel, hyaluronic acid methacrylate and multi-modal deformation sensing hydrogel in Example 1 of the present application is shown in the figure;

[0042] Figure 3 The scanning electron microscope (SEM) graph of the fiber structure of the multi-modal deformation sensing hydrogel in Example 1 of the present application is shown in the figure;

[0043] Figure 4 SEM image of the pore structure of the multi-modal deformation sensing hydrogel in Example 1 of the present application;

[0044] Figure 5 SEM image of the cross section of the multi-modal deformation sensing hydrogel in Example 1 of the present application;

[0045] Figure 6 Sensing performance graph of the multi-modal deformation sensing hydrogel in Example 1 of the present application under tensile strain;

[0046] Figure 7 Sensing performance graph of the multi-modal deformation sensing hydrogel in Example 1 of the present application under compressive strain;

[0047] Figure 8 Sensing performance graph of the multi-modal deformation sensing hydrogel in Example 1 of the present application fixed on the heel part of the foot during walking;

[0048] Figure 9 Sensing performance graph of the multi-modal deformation sensing hydrogel in Example 1 of the present application fixed on the toe ball part of the foot during walking;

[0049] Figure 10 Sensing performance graph of the multi-modal deformation sensing hydrogel in Example 1 of the present application fixed on the heel part of the foot during walking, running and jumping. DETAILED DESCRIPTION

[0050] The present application will be described in detail below with specific examples. The present embodiment is implemented on the premise of the technical solution of the present application, and detailed implementation and specific operation processes are given, but the protection scope of the present application is not limited to the following examples.

[0051] The equipment used in the following examples is conventional in the art unless otherwise specified; the reagents used are commercially available or prepared by conventional methods in the art unless otherwise specified; and the details not described in the following examples can be achieved by conventional experimental means in the art.

[0052] The mechanical properties, electrical properties and sensing properties of the multi-modal deformation sensing hydrogel prepared in the present embodiment were characterized using an LD23503 universal tensile testing machine, a Biologic VMP-3 electrochemical workstation and a Keithley 2450 source meter.

[0053] Example 1:

[0054] A multi-modal deformation sensing hydrogel and a preparation method thereof, the specific steps are as follows:

[0055] S1, preparation of calcium alginate hydrogel,

[0056] 0.2 g of sodium alginate was added to 5 mL of deionized water and dissolved under continuous stirring at room temperature for 10 h to obtain a sodium alginate solution. 0.4 g of calcium chloride was dissolved in 5 mL of deionized water. 5 mL of the prepared sodium alginate solution was poured into a mold, and 5 mL of calcium chloride solution was injected from above. The mixture was reacted at room temperature for 4 h to obtain a calcium alginate hydrogel (AlgCa). The two long ends of the calcium alginate hydrogel were clamped with a bracket and placed in air to dry at room temperature for 4 h.

[0057] S2. Preparation of methacrylated hyaluronic acid,

[0058] 0.1 g of hyaluronic acid (HA) was added to 5 mL of deionized water and dissolved by continuous stirring at room temperature for 4 h. 0.015 mL of glycidyl methacrylate, 0.015 mL of triethylamine, and 0.015 g of tetrabutylammonium bromide were added and reacted at 50°C for 2 h. After cooling to room temperature, the reacted solution was precipitated and washed in acetone and freeze-dried at -110°C for 12 h to obtain methacrylated hyaluronic acid (GMHA).

[0059] like Figure 1 As shown, the nuclear magnetic resonance spectrum shows that compared with hyaluronic acid, the methacrylated hyaluronic acid prepared in this example has two new proton peaks caused by methacrylate groups at 5.22ppm and 5.50ppm;

[0060] like Figure 2 As shown in the total reflection infrared absorption spectrum (ATR-FTIR), the methacrylated hyaluronic acid prepared in this example has a higher wavelength at 1375 cm-1 than the calcium alginate hydrogel (AlgCa). -1 and 1153cm -1 There is an obvious characteristic peak at , which is caused by the carbon-carbon double bond (RC=CH2) functional group;

[0061] The test results of nuclear magnetic resonance spectroscopy and total reflection infrared absorption spectroscopy proved that the methacrylate hyaluronic acid in this embodiment was successfully synthesized;

[0062] S3. Preparation of multimodal deformation sensing hydrogels.

[0063] 0.1 g of methacrylated hyaluronic acid was added to 4 mL of deionized water and dissolved by continuous stirring at room temperature for 1 h. 0.0001 g of N,N-methylenebisacrylamide and 0.0002 g of ammonium persulfate were added and mixed by continuous stirring at room temperature for 10 min. The mixed solution was injected into a mold and polymerized with 0.15 g of calcium alginate hydrogel under anaerobic conditions at 40 °C for 3 h to obtain a multimodal deformation sensing hydrogel (AMH).

[0064] The performance of the above-mentioned sensing hydrogel was tested, and the specific results are as follows:

[0065] T1, the test results of the total reflection infrared absorption spectrum of the material,

[0066] As shown in Figure 2 , the total reflection infrared absorption spectrum shows that the crosslinking reaction occurs between the hyaluronic acid methacrylic acid molecules, and in this process, the carbon-carbon double bond is destroyed, which is reflected in the spectrum as the disappearance of the absorption band representing the existence of double bonds at 1375 cm -1 and 1153 cm -1 in the multimodal deformation sensing hydrogel in this embodiment;

[0067] Further observation shows that the hyaluronic acid methacrylic acid spectrum appears a wide absorption peak in the 3640-2980 cm -1 region, which is due to the participation of the -OH and -NH groups in the molecule in the formation of intramolecular and intermolecular hydrogen bonds, resulting in the enhancement of the stretching vibration;

[0068] In contrast, the calcium alginate hydrogel forms a stable chelate structure with Ca 2+ and -OH and -COOH groups, thereby weakening the performance of these groups in the spectrum, making it difficult to observe the corresponding absorption peak;

[0069] A wide peak is also observed in the same position in the multimodal deformation sensing hydrogel, proving the successful synthesis of the multimodal deformation sensing hydrogel in this embodiment;

[0070] T2, the test results of the scanning electron microscope (SEM) of the material,

[0071] As shown in Figure 3 , the multimodal deformation sensing hydrogel prepared in this embodiment observed the fibers arranged along the axial direction, and through in-situ clamping, the calcium alginate hydrogel formed a thick fiber structure arranged along the axial direction, and each ultrafine fiber was sub-micron in size;

[0072] As shown in Figure 4 , the oriented porous structure was observed in the multimodal deformation sensing hydrogel prepared in this embodiment, and the hyaluronic acid methacrylic acid took the oriented fiber structure as a template, and the pores grew along the fibers, and the pore walls were parallel to the arrangement direction of the fibers, forming oriented pores;

[0073] As shown in Figure 5 , the multimodal deformation sensing hydrogel prepared in this embodiment showed a fiber-pore-fiber multilayer sandwich structure, indicating that the multimodal deformation sensing hydrogel prepared in this embodiment was composed of oriented fibers and oriented pores;

[0074] T3, the test results of the mechanical properties of the material,

[0075] The mechanical property data of the sensing hydrogel is shown in Table 1.

[0076] Table 1 Mechanical property data of the multi-modal deformation sensing hydrogel in the embodiment

[0077] Example Maximum tensile elongation Maximum tensile strength (MPa) Maximum compressive strength (MPa) 1 102％ 1.51 3.5 2 93％ 1.64 2.9 3 86％ 1.25 2.3 4 135％ 1.34 2.5 5 115％ 1.44 3.2 6 121％ 1.27 2.9

[0078] As shown in Table 1, the tensile results show that the multi-modal deformation sensing hydrogel prepared in the embodiment has a maximum tensile elongation of 102% and a maximum tensile strength of 1.51 MPa.

[0079] The compression results show that when the multi-modal deformation sensing hydrogel prepared in the embodiment is compressed to 70%, the maximum compression strength reaches 3.5 MPa.

[0080] It is shown that the multi-modal deformation sensing hydrogel prepared in the embodiment has excellent tensile and compression mechanical properties.

[0081] T4, the test results of the electrical conductivity of the material,

[0082] The electrical conductivity data of the sensing hydrogel is shown in Table 2.

[0083] Table 2 Electrical conductivity data of the multi-modal deformation sensing hydrogel in the embodiment

[0084] Example 1 2 3 4 5 6 Electrical conductivity (S / cm) 0.044 0.031 0.036 0.027 0.04 0.035

[0085] As shown in Table 2, the electrical conductivity of the multi-modal deformation sensing hydrogel prepared in the embodiment is 0.044 S / cm, which shows that the multi-modal deformation sensing hydrogel prepared in the embodiment has excellent electrical conductivity.

[0086] T5, the test results of the sensing performance of the material,

[0087] As shown in Table 3, under different tensile strains (1%, 2%, 5%, 10% and 20%), the relative resistance change of the multi-modal deformation sensing hydrogel prepared in the embodiment continuously increases with the increase of the tensile strain, which shows that the multi-modal deformation sensing hydrogel prepared in the embodiment can convert the tensile deformation into a stable electrical signal and exhibits good mechanical responsiveness. Figure 6 As shown in Table 4, under different compression strains (1%, 2%, 5%, 10% and 20%), the relative resistance change of the multi-modal deformation sensing hydrogel prepared in the embodiment continuously decreases with the increase of the compression strain, which shows that the multi-modal deformation sensing hydrogel prepared in the embodiment can convert the compression deformation into a stable electrical signal and exhibits good mechanical responsiveness.

[0088] Figure 7 As shown in Table 4, under different compression strains (1%, 2%, 5%, 10% and 20%), the relative resistance change of the multi-modal deformation sensing hydrogel prepared in the embodiment continuously decreases with the increase of the compression strain, which shows that the multi-modal deformation sensing hydrogel prepared in the embodiment can convert the compression deformation into a stable electrical signal and exhibits good mechanical responsiveness. ​

[0089] The material was fixed on the heel of subjects with medium arches and they walked;

[0090] like Figure 8 As shown in the figure, during walking, when the heel is lowered, the pressure increases to the maximum value. When the whole foot is placed on the ground and the foot continues to move forward, the heel is raised and the pressure gradually decreases to zero. The relative resistance of the multimodal deformation sensing hydrogel prepared in this embodiment changes regularly during the walking process.

[0091] The material was fixed on the ball of the foot of subjects with medium arches and they walked;

[0092] like Figure 9 As shown, during walking, after placing the ball of the toe on the floor, the heel is slowly lifted, and the pressure on the ball of the toe increases to a maximum value. Continuing forward, the ball of the toe is lifted, and the pressure gradually decreases to zero. The relative resistance of the multimodal deformation sensing hydrogel prepared in this embodiment changes regularly during the walking process.

[0093] During walking, due to the difference in force, the peak current, peak shape, and interval time between the heel and the ball of the toes showed obvious differences, demonstrating that the multimodal deformation sensing hydrogel prepared in this example has a three-dimensional sensing range and the ability to distinguish plantar pressure points;

[0094] The material was fixed on the heel of subjects with medium arches and they performed walking, running and jumping activities.

[0095] like Figure 10 As shown in the figure, the multimodal deformation sensing hydrogel prepared in this embodiment has significantly different sensing signals in each motion scene. During walking, the peak width is large, showing a wide peak feature. Running and jumping have faster movement frequencies and more concentrated forces, so the peak width decreases and the peak shape becomes sharper.

[0096] High-speed motion will produce faster mechanical impact, resulting in a harsher environment for sensing response. However, the multimodal deformation sensing hydrogel prepared in this embodiment accurately and stably completed the sensing response.

[0097] The multimodal deformation sensing hydrogel prepared in this embodiment has a special three-dimensional response ability, which allows different movement patterns to generate different current signals. Through different electrical signal waveforms, the human body's movement pattern, movement frequency and force area can be quickly and accurately judged. It is a promising candidate in the fields of sports science, infant health and rehabilitation training.

[0098] Example 2:

[0099] A multimodal deformation sensing hydrogel and a preparation method thereof, the specific steps are as follows:

[0100] S1, preparation of calcium alginate hydrogel,

[0101] 0.5 g of sodium alginate was added to 10 mL of deionized water, and dissolved at room temperature for 12 h under continuous stirring to obtain a sodium alginate solution. 0.5 g of calcium chloride was dissolved in 10 mL of deionized water. 10 mL of the prepared sodium alginate solution was poured into a mold, and 10 mL of the calcium chloride solution was injected from the top. The reaction was carried out at room temperature for 4 h to obtain a calcium alginate hydrogel. The two long ends of the calcium alginate hydrogel were clamped using a bracket, and dried at room temperature in air for 4 h.

[0102] S2, preparation of hyaluronic acid methacrylate,

[0103] 0.2 g of hyaluronic acid was added to 8 mL of deionized water, and dissolved at room temperature for 4 h under continuous stirring. 0.03 mL of glycidyl methacrylate, 0.03 mL of triethylamine, and 0.03 g of tetrabutylammonium bromide were added, and the reaction was carried out at 50°C for 4 h. After cooling to room temperature, the completed reaction solution was precipitated and washed in acetone, and freeze-dried at -100°C for 24 h to obtain hyaluronic acid methacrylate.

[0104] S3, preparation of a multimodal deformation sensing hydrogel,

[0105] 0.15 g of hyaluronic acid methacrylate was added to 4 mL of deionized water, and dissolved at room temperature for 2 h under continuous stirring. 0.00015 g of N,N-methylenebisacrylamide and 0.0003 g of ammonium persulfate were added, and the mixture was continuously stirred at room temperature for 15 min. The mixed solution was injected into a mold, and polymerized with 0.3 g of calcium alginate hydrogel under anaerobic conditions and at 45°C for 3 h to form a multimodal deformation sensing hydrogel.

[0106] As shown in Table 1, the tensile results show that the multimodal deformation sensing hydrogel prepared in this embodiment has a maximum tensile elongation of 93% and a maximum tensile strength of 1.64 MPa;

[0107] The compression results show that when the multimodal deformation sensing hydrogel prepared in this embodiment is compressed to 70%, the maximum compression strength reaches 2.9 MPa;

[0108] It is shown that the multimodal deformation sensing hydrogel prepared in this embodiment has excellent tensile and compression mechanical properties;

[0109] As shown in Table 2, the conductivity of the multimodal deformation sensing hydrogel prepared in this embodiment is 0.031 S / cm, indicating that the multimodal deformation sensing hydrogel prepared in this embodiment has excellent conductivity.

[0110] Example 3:

[0111] A multimodal deformation sensing hydrogel and a preparation method thereof, the specific steps are as follows:

[0112] S1, preparation of calcium alginate hydrogel,

[0113] 2g of sodium alginate was added to 50mL of deionized water, and dissolved under continuous stirring at room temperature for 10h to obtain a sodium alginate solution, 6g of calcium chloride was dissolved in 100mL of deionized water, 50mL of the prepared sodium alginate solution was poured into a mold, 100mL of calcium chloride solution was injected from the top, and reacted at room temperature for 3h to obtain a calcium alginate hydrogel, the two long ends of the calcium alginate hydrogel were clamped using a bracket, and dried in air at room temperature for 4h;

[0114] S2, preparation of hyaluronic acid methacrylate,

[0115] 1.5g of hyaluronic acid was added to 50mL of deionized water, and dissolved under continuous stirring at room temperature for 3h, 0.2mL of glycidyl methacrylate, 0.2mL of triethylamine and 0.2g of tetrabutylammonium bromide were added, and reacted at 52℃ for 3h, and then the reaction solution was precipitated and washed in acetone after cooling to room temperature, and freeze-dried at-95℃ for 24h to obtain hyaluronic acid methacrylate;

[0116] S3, preparation of a multimodal deformation sensing hydrogel,

[0117] 1.5g of hyaluronic acid methacrylate was added to 50mL of deionized water, and dissolved under continuous stirring at room temperature for 2h, 0.0015g of N,N-methylene bisacrylamide and 0.0045g of potassium persulfate were added, and mixed under continuous stirring at room temperature for 10min, the mixed solution was injected into a mold, and was polymerized with 2g of calcium alginate hydrogel under anaerobic and 50℃ conditions for 5h to form a multimodal deformation sensing hydrogel.

[0118] As shown in Table 1, the tensile results show that the multimodal deformation sensing hydrogel prepared in this embodiment has a maximum tensile elongation of 86% and a maximum tensile strength of 1.25MPa;

[0119] The compression results show that when the multimodal deformation sensing hydrogel prepared in this embodiment is compressed to 70%, the maximum compression strength reaches 2.3MPa;

[0120] It is shown that the multimodal deformation sensing hydrogel prepared in this embodiment has excellent tensile and compression mechanical properties;

[0121] As shown in Table 2, the conductivity of the multi-modal deformation sensing hydrogel prepared in the embodiment is 0.036 S / cm, indicating that the multi-modal deformation sensing hydrogel prepared in the embodiment has excellent conductivity.

[0122] Embodiment 4:

[0123] A multi-modal deformation sensing hydrogel and a preparation method thereof, and the specific steps are as follows:

[0124] S1, preparation of calcium alginate hydrogel,

[0125] 0.5 g of sodium alginate was added to 10 mL of deionized water, and dissolved at room temperature for 12 h under continuous stirring to obtain a sodium alginate solution. 0.8 g of calcium chloride was dissolved in 10 mL of deionized water. 10 mL of the prepared sodium alginate solution was poured into a mold, and 10 mL of calcium chloride solution was injected from the top. The reaction was carried out at room temperature for 5 h to obtain a calcium alginate hydrogel. The two long ends of the calcium alginate hydrogel were clamped using a support, and dried in air at room temperature for 5 h.

[0126] S2, preparation of hyaluronic acid methacrylate,

[0127] 0.2 g of hyaluronic acid was added to 10 mL of deionized water, and dissolved at room temperature for 4 h under continuous stirring. 0.03 mL of glycidyl methacrylate, 0.03 mL of triethylamine and 0.03 g of tetrabutylammonium bromide were added, and the reaction was carried out at 50°C for 3 h. After cooling to room temperature, the completed reaction solution was precipitated and washed in acetone, and freeze-dried at -110°C for 18 h to obtain hyaluronic acid methacrylate.

[0128] S3, preparation of multi-modal deformation sensing hydrogel,

[0129] 0.2 g of hyaluronic acid methacrylate was added to 10 mL of deionized water, and dissolved at room temperature for 1 h under continuous stirring. 0.00025 g of N,N-methylene bisacrylamide and 0.00055 g of potassium persulfate were added, and the mixture was continuously stirred at room temperature for 10 min. The mixed solution was injected into a mold, and polymerized with 0.5 g of calcium alginate hydrogel under anaerobic and 40°C conditions for 6 h to form a multi-modal deformation sensing hydrogel.

[0130] As shown in Table 1, the tensile results show that the multi-modal deformation sensing hydrogel prepared in the embodiment has a maximum tensile elongation of 135% and a maximum tensile strength of 1.34 MPa.

[0131] The compression results show that when the multi-modal deformation sensing hydrogel prepared in the embodiment is compressed to 70%, the maximum compression strength reaches 2.5 MPa.

[0132] The multi-modal deformation sensing hydrogel prepared in the embodiment has excellent mechanical properties of resisting stretching and compression.

[0133] As shown in Table 2, the conductivity of the multi-modal deformation sensing hydrogel prepared in the embodiment is 0.027 S / cm, indicating that the multi-modal deformation sensing hydrogel prepared in the embodiment has excellent electrical conductivity.

[0134] Embodiment 5:

[0135] A multi-modal deformation sensing hydrogel and a preparation method thereof, and the specific steps are as follows:

[0136] S1, preparation of calcium alginate hydrogel,

[0137] 3 g of sodium alginate was added to 50 mL of deionized water, and dissolved under continuous stirring at room temperature for 8 h to obtain a sodium alginate solution. 2 g of calcium chloride was dissolved in 50 mL of deionized water. 50 mL of the prepared sodium alginate solution was poured into a mold, and 50 mL of calcium chloride solution was injected from the top. The reaction was carried out at room temperature for 5 h to obtain a calcium alginate hydrogel. The two long ends of the calcium alginate hydrogel were clamped using a support and dried in air at room temperature for 6 h.

[0138] S2, preparation of hyaluronic acid methacrylate,

[0139] 2 g of hyaluronic acid was added to 50 mL of deionized water, and dissolved under continuous stirring at room temperature for 4 h. 0.2 mL of glycidyl methacrylate, 0.2 mL of triethylamine and 0.2 g of tetrabutylammonium bromide were added, and the reaction was carried out at 50°C for 4 h. After cooling to room temperature, the completed reaction solution was precipitated and washed in acetone, and freeze-dried at -100°C for 24 h to obtain hyaluronic acid methacrylate.

[0140] S3, preparation of multi-modal deformation sensing hydrogel,

[0141] 2 g of hyaluronic acid methacrylate was added to 50 mL of deionized water, and dissolved under continuous stirring at room temperature for 2 h. 0.002 g of N,N-methylene bisacrylamide and 0.004 g of ammonium persulfate were added, and the mixture was continuously stirred at room temperature for 15 min. The mixed solution was injected into a mold, and was polymerized with 3 g of calcium alginate hydrogel under anaerobic conditions and at 45°C for 6 h to form a multi-modal deformation sensing hydrogel.

[0142] As shown in Table 1, the stretching results show that the multi-modal deformation sensing hydrogel prepared in the embodiment has a maximum tensile elongation of 115% and a maximum tensile strength of 1.44 MPa.

[0143] The compression results show that when the multi-modal deformation sensing hydrogel prepared in the embodiment is compressed to 70%, the maximum compression resistance reaches 3.2 MPa;

[0144] It is shown that the multi-modal deformation sensing hydrogel prepared in the embodiment has excellent tensile and compression resistance mechanical properties.

[0145] As shown in Table 2, the conductivity of the multi-modal deformation sensing hydrogel prepared in the embodiment is 0.04 S / cm, indicating that the multi-modal deformation sensing hydrogel prepared in the embodiment has excellent conductivity.

[0146] Embodiment 6:

[0147] A multi-modal deformation sensing hydrogel and a preparation method thereof, and the specific steps are as follows:

[0148] S1, preparation of calcium alginate hydrogel,

[0149] 0.5 g of sodium alginate was added to 10 mL of deionized water, and dissolved under continuous stirring at room temperature for 8 h to obtain a sodium alginate solution. 0.4 g of calcium chloride was dissolved in 8 mL of deionized water. 10 mL of the prepared sodium alginate solution was poured into a mold, and 8 mL of calcium chloride solution was injected from the top. The reaction was carried out at room temperature for 5 h to obtain a calcium alginate hydrogel. The two long ends of the calcium alginate hydrogel were clamped using a support, and the calcium alginate hydrogel was dried in air at room temperature for 4 h.

[0150] S2, preparation of hyaluronic acid methacrylate,

[0151] 0.4 g of hyaluronic acid was added to 10 mL of deionized water, and dissolved under continuous stirring at room temperature for 4 h. 0.06 mL of glycidyl methacrylate, 0.06 mL of triethylamine and 0.06 g of tetrabutylammonium bromide were added, and the reaction was carried out at 50°C for 2 h. After cooling to room temperature, the completed reaction solution was precipitated and washed in acetone, and freeze-dried at -90°C for 24 h to obtain hyaluronic acid methacrylate.

[0152] S3, preparation of multi-modal deformation sensing hydrogel,

[0153] 0.4 g of hyaluronic acid methacrylate was added to 11 mL of deionized water, and dissolved under continuous stirring at room temperature for 1 h. 0.0004 g of N,N-methylene bisacrylamide and 0.0006 g of ammonium persulfate were added, and the mixture was continuously stirred at room temperature for 10 min. The mixed solution was injected into a mold, and was polymerized with 0.5 g of calcium alginate hydrogel under anaerobic and 45°C conditions for 6 h to form a multi-modal deformation sensing hydrogel.

[0154] As shown in Table 1, the tensile results show that the multi-modal deformation sensing hydrogel prepared in the embodiment has a maximum tensile elongation of 121% and a maximum tensile strength of 1.27 MPa;

[0155] The compression results show that when the multi-modal deformation sensing hydrogel prepared in the embodiment is compressed to 70%, the maximum compression strength reaches 2.9 MPa;

[0156] It is shown that the multi-modal deformation sensing hydrogel prepared in the embodiment has excellent tensile and compression mechanical properties;

[0157] As shown in Table 2, the conductivity of the multi-modal deformation sensing hydrogel prepared in the embodiment is 0.035 S / cm, indicating that the multi-modal deformation sensing hydrogel prepared in the embodiment has excellent conductivity.

[0158] The multi-modal deformation sensing hydrogel prepared in the application can sense and recognize different movement modes, and has good application potential in personalized medical care and sports rehabilitation.

[0159] The above description of the embodiments is for facilitating the ordinary skilled person in the art to understand and use the application. The person skilled in the art can obviously easily make various modifications to the embodiments, and apply the general principles described herein to other embodiments without creative labor. Therefore, the application is not limited to the above embodiments, and the improvements and modifications made by the person skilled in the art according to the disclosure of the application without departing from the scope of the application should be within the protection scope of the application.

Claims

1. A multimodal deformation sensing hydrogel, characterized in that: The raw materials of the sensing hydrogel include the following components in parts by weight: 1-3 parts alginate hydrogel and 1-3 parts methacrylated hyaluronic acid; The preparation method of the sensing hydrogel comprises: Sodium alginate is dissolved in water to obtain a sodium alginate solution, and a metal ion solution is added to react to obtain an alginate hydrogel. The two long ends of the alginate hydrogel are clamped and placed in air at 10-40°C to dry to form a layered fiber structure. Methacrylate hyaluronic acid is dissolved in water, a cross-linking agent and an initiator are added and mixed, and then polymerized with alginate hydrogel to obtain a multimodal deformation sensing hydrogel.

2. The multimodal deformation sensing hydrogel according to claim 1, characterized in that: The drying time is 3~6h.

3. The multimodal deformation sensing hydrogel according to claim 1, characterized in that: Methacrylated hyaluronic acid and alginate hydrogel are polymerized under anaerobic and heat-induced conditions, with the polymerization temperature being 40-60°C and the polymerization time being 3-6 hours.

4. A method for preparing a multimodal deformation sensing hydrogel according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: S1. Sodium alginate is added to water to dissolve to obtain a sodium alginate solution, and a metal ion solution is added to react to obtain an alginate hydrogel. The two long ends of the alginate hydrogel are clamped and placed in air at 10-40°C to dry to form a layered fiber structure. S2, adding hyaluronic acid to water to dissolve, adding glycidyl methacrylate, triethylamine and tetrabutylammonium bromide to react, to obtain methacrylate hyaluronic acid; S3. Add methacrylate hyaluronic acid into water to dissolve it, add a cross-linking agent and an initiator to mix, and polymerize it with alginate hydrogel to obtain a multimodal deformation sensing hydrogel.

5. The method for preparing a multimodal deformation sensing hydrogel according to claim 4, characterized in that: The mass / volume ratio of sodium alginate to water in step S1 is (1-2 g):(25-30 mL), The metal ion solution is selected from one or more of calcium chloride solution, zinc chloride solution, and barium chloride solution, and the concentration of the metal ion solution is 0.05-0.1 g / mL. The volume ratio of sodium alginate solution to metal ion solution is (1~2):(1~3).

6. The method for preparing a multimodal deformation sensing hydrogel according to claim 4, characterized in that: The dissolution temperature in step S1 is 10-40°C and the dissolution time is 8-12 h. The reaction temperature is 10~40 ℃ and the reaction time is 3~6 h.

7. The method for preparing a multimodal deformation sensing hydrogel according to claim 4, characterized in that: The mass / volume ratio of hyaluronic acid to water in step S2 is (1-3 g):(50-60 mL), The mass / volume ratio of hyaluronic acid, glycidyl methacrylate, triethylamine, and tetrabutylammonium bromide is (45-50 g):(1-8 mL):(1-8 mL):(1-8 g).

8. The method for preparing a multimodal deformation sensing hydrogel according to claim 4, characterized in that: The dissolution temperature in step S2 is 10-40°C and the dissolution time is 3-6 h. The reaction temperature is 40~60 ℃ and the reaction time is 1~4 h.

9. The method for preparing a multimodal deformation sensing hydrogel according to claim 4, characterized in that: The mass / volume ratio of methacrylated hyaluronic acid to water in step S3 is (0.02-0.04 g):1 mL, The crosslinking agent is selected from one or more of polyethylene glycol diacrylate, N,N-methylenebisacrylamide, and triallyl isocyanurate; the initiator is selected from one or more of ammonium persulfate, potassium persulfate, 2-hydroxy-2-methylpropiophenone, and α-ketoglutaric acid; the mass ratio of methacrylate hyaluronic acid, crosslinking agent, and initiator is 1:(0.001-0.002):(0.002-0.003); The dissolution temperature is 10~40℃ and the dissolution time is 1~2 hours. The mixing temperature is 10~40℃ and the mixing time is 10~20 min.

10. A use of the multimodal deformation sensing hydrogel according to any one of claims 1 to 3, characterized in that: The sensing hydrogel is applied to wearable flexible sensors.

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