Double-nanostructure reinforced collagenous fiber-based flexible sensor and preparation method thereof

Abstract

The invention discloses a preparation method of a double-nano-structure reinforced collagenous fiber-based flexible sensor. The preparation method specifically comprises the following steps: step 1, preparing a double-nano composite material; step 2, preparing modified leather collagen fibers; and step 3, preparing the double-nanostructure reinforced collagenous fiber-based flexible sensor according to products obtained in the step 1 and the step 2. The invention further discloses a double-nanostructure reinforced collagenous fiber-based flexible sensor. The problems that an existing sensor is insufficient in conductivity and insensitive in response to weak signals are solved through the double-nanostructure reinforced collagenous fiber-based flexible sensor and the preparation method of the double-nanostructure reinforced collagenous fiber-based flexible sensor.

Description

Technical Field

[0001] This invention belongs to the field of flexible sensing technology, and relates to a flexible sensor based on collagen fibers with dual nanostructure enhancement. This invention also relates to a method for preparing a flexible sensor based on collagen fibers with dual nanostructure enhancement. Background Technology

[0002] In recent years, conductive hydrogels have been extensively studied as substrate materials for flexible electronic devices. However, their high water content can lead to unstable sensing performance and poor durability. Poor compatibility between various building blocks makes it difficult to achieve both high mechanical strength and good sensing performance. Furthermore, their susceptibility to environmental factors can reduce their lifespan. These issues greatly limit their widespread application in the field of flexible electronics.

[0003] Collagen fibers, primarily derived from mammalian skin tissue, are natural fibers formed by the aggregation of collagen fibrils, the quaternary structure of collagen. Flexible sensors fabricated using collagen fibers as a substrate not only exhibit better biocompatibility and environmental friendliness than traditional inorganic flexible sensors, but also demonstrate stronger mechanical properties and stability than flexible sensors based on conductive hydrogels. On one hand, the abundant active functional groups in collagen molecular chains make it a suitable material choice for flexible sensor substrates; on the other hand, the unique multi-level structure of collagen fibers facilitates the construction of sensitive sensing units to enhance sensing sensitivity. Furthermore, the excellent flexibility, bio-tissue-like mechanical properties, and biocompatibility of collagen fiber substrates give them great application potential in fields such as electronic skin. Therefore, developing flexible sensors based on skin collagen fibers can simultaneously achieve good biocompatibility, environmental friendliness, and excellent flexibility and mechanical properties. However, using collagen fibers alone as a sensor substrate still suffers from insufficient conductivity and inadequate sensitivity to weak signals. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a flexible sensor based on collagen fibers with a dual nanostructure enhancement, which solves the problems of insufficient conductivity and insensitive response to weak signals in existing sensors.

[0005] Another objective of this invention is to provide a flexible sensor based on collagen fibers with a dual nanostructure enhancement.

[0006] The first technical solution adopted in this invention is a method for preparing a flexible sensor based on collagen fibers with a dual nanostructure enhancement, which specifically includes the following steps: Step 1: Prepare dual nanocomposite materials; Step 2: Prepare modified skin collagen fibers; Step 3: Prepare a double nanostructure-enhanced collagen fiber-based flexible sensor based on the products obtained in Step 1 and Step 2.

[0007] The first technical solution of this invention is further characterized by: The specific process of step 1 is as follows: prepare lithium diatomaceous earth nanosheet dispersion, dopamine hydrochloride solution and carbon nanotube dispersion at room temperature, mix them and then ultrasonically disperse them to obtain a dual nanocomposite material.

[0008] In step 1, the volume ratio of lithium diatomaceous earth nanosheet dispersion, dopamine hydrochloride solution and carbon nanotube dispersion is 1:0.1:0.5~2.0.

[0009] The specific process of step 2 is as follows: prepare an acid solution with sodium chloride, formic acid and water, immerse the leather in the acid solution, add tannic acid to the acid solution, and after standing, obtain modified leather collagen fibers.

[0010] In step 2, the mass ratio of tannic acid to leather is 1:0.02~0.04.

[0011] In step 2, the mass ratio of sodium chloride, formic acid, and water is 1:0.25:25.

[0012] The specific process of step 3 is as follows: Step 3.1: Vacuum-assisted filtration of the dual nanocomposite material obtained in Step 1 onto the collagen fibers obtained in Step 2; Step 3.2: Dry the collagen fibers obtained in step 3.1 in an oven to obtain a flexible sensor based on collagen fibers with a dual nanostructure.

[0013] The second technical solution adopted in this invention is a double nanostructure-enhanced collagen fiber-based flexible sensor, which is prepared by the above-mentioned method for preparing a double nanostructure-enhanced collagen fiber-based flexible sensor.

[0014] The beneficial effects of this invention are as follows: (1) The present invention uses skin collagen fiber as a base and combines lithium diatomite nanosheets and carbon nanotubes to form a dual nano-reinforcement system, which significantly improves the conductivity and mechanical strength of the sensor, so that it can maintain stable sensing performance under bending, stretching and other deformations. (2) By modifying collagen fibers with tannic acid, the active sites on the fiber surface are enhanced, the binding strength with nanomaterials is improved, and the sensor has better structural stability and durability. (3) The preparation method is simple and mild, suitable for large-scale production, and the resulting sensor has broad application prospects in fields such as flexible electronics, health monitoring and electronic skin. Attached Figure Description

[0015] Figure 1 A photograph of the flexible sensor prepared in Example 7 of the preparation method of the dual nanostructure-enhanced collagen fiber-based flexible sensor of the present invention. Figure 2 This is a scanning electron microscope image of the flexible sensor prepared in Example 7 of the preparation method of the dual nanostructure-enhanced collagen fiber-based flexible sensor of the present invention. Figure 3 Example 7 shows the time-relative resistance diagram of the flexible sensor prepared by the method of preparing the dual nanostructure-enhanced collagen fiber-based flexible sensor of the present invention under pressure deformation. Figure 4 The response time and recovery time of the flexible sensor prepared in Example 7 of the preparation method of the dual nanostructure-enhanced collagen fiber-based flexible sensor of the present invention are shown. Detailed Implementation

[0016] The following detailed description is provided in conjunction with specific implementation methods.

[0017] The method for preparing a dual-nanostructure-enhanced collagen fiber-based flexible sensor according to the present invention specifically includes the following steps: Step 1, the preparation of the dual nanocomposite material, specifically involves: At room temperature, a dispersion of 10 mg / mL lithium diatomite nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared, respectively. After mixing, the mixture was ultrasonically dispersed for 30 min to obtain the nanocomposite material. In step 1, the volume ratio of lithium diatomaceous earth nanosheet dispersion, dopamine hydrochloride solution and carbon nanotube dispersion is 1:0.1:(0.5~2.0). Step 2, the preparation of modified skin collagen fibers, specifically includes: An acid solution was prepared using sodium chloride, formic acid, and water. The leather was then immersed in the acid solution, and tannic acid was added. After standing for 6 hours, modified leather collagen fibers were obtained.

[0018] In step 2, the mass ratio of sodium chloride, formic acid, and water is 1:0.25:25; In step 2, the mass ratio of leather to tannic acid is 1:(0.02~0.04). Step 3, the fabrication of the dual-nanostructure-enhanced collagen fiber-based flexible sensor, specifically involves: First, the dual nanocomposite material obtained in step 1 is vacuum-assisted filtered onto the collagen fiber obtained in step 2; then, the collagen fiber is placed at 35°C until completely dry to obtain a flexible sensor based on collagen fiber reinforced by dual nanostructure.

[0019] Example 1 First, a dispersion of 10 mg / mL lithium diatomaceous earth nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared at room temperature. These were then mixed at a volume ratio of 1:0.1:0.5 and ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Next, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.02 to obtain modified leather collagen fibers. Then, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were dried completely at 35°C to obtain a flexible sensor based on a dual-nanostructure-reinforced collagen fiber base.

[0020] Example 2 First, a dispersion of 10 mg / mL lithium diatomaceous earth nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared at room temperature. These were then mixed at a volume ratio of 1:0.1:1.0 and ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Subsequently, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.02 to obtain modified leather collagen fibers. Next, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were dried completely at 35°C to obtain a flexible sensor based on a dual-nanostructure-reinforced collagen fiber base.

[0021] Example 3 First, a dispersion of 10 mg / mL lithium diatomaceous earth nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared at room temperature. These were then mixed at a volume ratio of 1:0.1:2.0 and ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Next, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.02 to obtain modified leather collagen fibers. Then, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were dried completely at 35°C to obtain a flexible sensor based on a dual-nanostructure-reinforced collagen fiber base.

[0022] Example 4 First, a dispersion of 10 mg / mL lithium diatomaceous earth nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared at room temperature. These were then mixed at a volume ratio of 1:0.1:0.5 and ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Next, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.03 to obtain modified leather collagen fibers. Then, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were dried completely at 35°C to obtain a flexible sensor based on a dual-nanostructure-reinforced collagen fiber base.

[0023] Example 5 First, a 10 mg / mL lithium diatomaceous earth nanosheet dispersion, a 2 mg / mL dopamine hydrochloride solution, and a 10 mg / mL carbon nanotube dispersion were prepared at room temperature and mixed at a volume ratio of 1:0.1:1.0. The mixture was then ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Subsequently, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.03 to obtain modified leather collagen fibers. Next, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were placed at 35°C until completely dry to obtain a dual-nanostructure-reinforced collagen fiber-based flexible sensor.

[0024] Example 6 First, a dispersion of 10 mg / mL lithium diatomaceous earth nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared at room temperature. These were then mixed at a volume ratio of 1:0.1:2.0 and ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Next, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.03 to obtain modified leather collagen fibers. Then, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were dried completely at 35°C to obtain a flexible sensor based on a dual-nanostructure-reinforced collagen fiber base.

[0025] Example 7 First, a 10 mg / mL lithium diatomaceous earth nanosheet dispersion, a 2 mg / mL dopamine hydrochloride solution, and a 10 mg / mL carbon nanotube dispersion were prepared at room temperature and mixed at a volume ratio of 1:0.1:0.5, followed by ultrasonic dispersion for 10 min to obtain a dual-nanocomposite material. Then, an acid solution was prepared with a sodium chloride, formic acid, and water mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.04 to obtain modified leather collagen fibers. Next, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were placed at 35°C until completely dry to obtain a dual-nanostructure-reinforced collagen fiber-based flexible sensor.

[0026] Figure 1 A digital photograph of the flexible sensor obtained in Example 7; Figure 2 SEM image of the flexible sensor obtained in Example 7; Figure 3 The image shows the time-relative resistance diagram of the flexible sensor prepared in Example 7 under pressure deformation.

[0027] Figure 4 The response time and recovery time of the flexible sensor prepared in Example 7 under bending deformation are given by R0 (initial resistance value, ΔR resistance change value).

[0028] Figure 1 This indicates that the flexible sensor has been successfully fabricated and, through... Figure 2 It can be seen that the dual composite material is well bonded to and dispersed on the collagen fibers. Figure 3 and Figure 4 The time-relative resistance graphs of the fabricated flexible sensor under different deformations show that it has good conductivity and sensitivity.

[0029] Example 8 First, a dispersion of 10 mg / mL lithium diatomaceous earth nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared at room temperature. These were then mixed at a volume ratio of 1:0.1:1.0 and ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Subsequently, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.04 to obtain modified leather collagen fibers. Next, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were dried completely at 35°C to obtain a flexible sensor based on a dual-nanostructure-reinforced collagen fiber base.

[0030] Example 9 First, a dispersion of 10 mg / mL lithium diatomaceous earth nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared at room temperature. These were then mixed at a volume ratio of 1:0.1:2.0 and ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Next, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.04 to obtain modified leather collagen fibers. Then, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were dried completely at 35°C to obtain a flexible sensor based on a dual-nanostructure-reinforced collagen fiber base.

[0031] Example 10 First, a dispersion of 10 mg / mL lithium diatomaceous earth nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared at room temperature. These were then mixed at a volume ratio of 1:0.1:2.0 and ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Next, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.03 to obtain modified leather collagen fibers. Then, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were dried completely at 35°C to obtain a flexible sensor based on a dual-nanostructure-reinforced collagen fiber base.

[0032] Example 11 First, a dispersion of 10 mg / mL lithium diatomaceous earth nanosheets, a solution of 2 mg / mL dopamine hydrochloride, and a dispersion of 10 mg / mL carbon nanotubes were prepared at room temperature. These were then mixed at a volume ratio of 1:0.1:1.5 and ultrasonically dispersed for 10 min to obtain a dual-nanocomposite material. Next, an acid solution was prepared using sodium chloride, formic acid, and water at a mass ratio of 1:0.25:25. Leather was immersed in the acid solution, and tannic acid was added. After standing for 6 h, modified leather collagen fibers were obtained. The mass ratio of leather to tannic acid was 1:0.04 to obtain modified leather collagen fibers. Then, the aforementioned dual-nanocomposite material was combined with the modified leather collagen fibers through vacuum-assisted filtration to obtain leather collagen fibers. Finally, the leather collagen fibers were dried completely at 35°C to obtain a flexible sensor based on a dual-nanostructure-reinforced collagen fiber base.

[0033] This invention discloses a method for preparing a flexible sensor based on collagen fibers with a dual-nanostructure enhancement. The process involves first preparing a dual-nanostructure and modified collagen fibers separately, then incorporating the dual-nanostructure into the collagen fibers and using vacuum-assisted filtration to prepare the sensor. The preparation method is simple and easy to implement. The dual-nanosystem composed of lithium diatomaceous earth nanosheets and carbon nanotubes effectively improves the conductivity of the collagen fiber substrate. Tannic acid modification further enhances the bonding force between the fiber interface and the nanomaterials, resulting in a sensor that possesses excellent flexibility, high sensitivity, and stable sensing performance, showing great application potential in flexible electronics, health monitoring, and smart wearable devices.

[0034] This invention introduces a dual-nano system composed of lithium diatomite nanosheets and carbon nanotubes, and combines it with tannic acid-modified collagen fibers, which effectively improves the conductivity, structural stability and signal response sensitivity of the sensor, while retaining the biocompatibility and mechanical flexibility of the collagen fibers themselves.

Claims

1. A method for fabricating a flexible sensor based on collagen fibers reinforced with dual nanostructures, characterized in that: Specifically, the steps include the following: Step 1: Prepare dual nanocomposite materials; Step 2: Prepare modified skin collagen fibers; Step 3: Prepare a flexible sensor based on a dual nanostructure-enhanced collagen fiber based on the products obtained in Step 1 and Step 2.

2. The method for preparing the dual-nanostructure-enhanced collagen fiber-based flexible sensor according to claim 1, characterized in that: The specific process of step 1 is as follows: prepare lithium diatomaceous earth nanosheet dispersion, dopamine hydrochloride solution and carbon nanotube dispersion at room temperature, mix them and then ultrasonically disperse them to obtain a dual nanocomposite material.

3. The method for preparing the dual-nanostructure-enhanced collagen fiber-based flexible sensor according to claim 2, characterized in that: In step 1, the volume ratio of lithium diatomaceous earth nanosheet dispersion, dopamine hydrochloride solution and carbon nanotube dispersion is 1:0.1:0.5~2.

0.

4. The method for preparing the dual-nanostructure-enhanced collagen fiber-based flexible sensor according to claim 3, characterized in that: The specific process of step 2 is as follows: prepare an acid solution with sodium chloride, formic acid and water, immerse the leather in the acid solution, add tannic acid to the acid solution, and obtain modified leather collagen fibers after standing.

5. The method for preparing the dual-nanostructure-enhanced collagen fiber-based flexible sensor according to claim 4, characterized in that: In step 2, the mass ratio of tannic acid to leather is 1:0.02~0.

04.

6. The method for preparing the dual-nanostructure-enhanced collagen fiber-based flexible sensor according to claim 4, characterized in that: In step 2, the mass ratio of sodium chloride, formic acid, and water is 1:0.25:

25.

7. The method for preparing the dual-nanostructure-enhanced collagen fiber-based flexible sensor according to claim 4, characterized in that: The specific process of step 3 is as follows: Step 3.1: Vacuum-assisted filtration of the dual nanocomposite material obtained in Step 1 onto the collagen fibers obtained in Step 2; Step 3.2: Dry the collagen fibers obtained in step 3.1 in an oven to obtain a flexible sensor based on collagen fibers with a dual nanostructure.

8. A dual-nanostructure-enhanced collagen fiber-based flexible sensor, prepared by the method described in any one of claims 1 to 7.

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