Ultrathin biomass conductive film and in-situ rapid preparation method and application thereof

Abstract

The invention relates to an ultrathin biomass conductive film as well as an in-situ rapid preparation method and application thereof, metal ions and biomacromolecule ligands with accessibility and biocompatibility form metal coordinate bonds, so that ultra-rapid in-situ one-step rapid molecular assembly of biomacromolecules is realized; the ultrathin electronic biofilm with high shape retention, customizable shape, degradability and low impedance is obtained in situ; due to the thin and flexible structure of the biological membrane, the biological membrane can be in better contact with biological tissues, and the risk of tissue damage and rejection reaction is reduced; the characteristic of being directly formed on the target substrate can ensure high conformal contact with any substrate, and the need for additional transfer of the soft film is eliminated; metal complexing enables epidermal electrons to have excellent stability; the ultrathin biomass conductive film disclosed by the invention can be well attached to the skin, and has a relatively great application prospect in the fields of electronic skin and medical diagnosis.

Description

Technical Field

[0001] This invention belongs to the field of biomass thin film preparation technology, specifically relating to an ultrathin biomass conductive thin film and its in-situ rapid preparation method and application. Background Technology

[0002] In recent years, with the rapid development of flexible electronics and wearable devices, functional thin film materials have shown great application potential in fields such as microelectronics, sensors, separation membranes, flexible devices and biomedicine.

[0003] Traditional thin film preparation methods often have significant limitations: they are either complex and time-consuming, making them difficult to complete quickly; or they require subsequent transfer steps, which can damage the integrity of the film and introduce defects, making it impossible to achieve true in-situ polymerization; and they are difficult to meet high conformity requirements for applications with complex curved surfaces and micro / nano structure substrates.

[0004] The inventors of this patent application filed a patent with patent number CN202411407517.2, entitled "An Invention Patent for a Low-Impedance Adhesive Ultrathin Cellulose Membrane and Its Preparation Method and Application". This patent application prepares an ultrathin cellulose membrane by metal complexation between metal ions released from metal materials and cellulose. However, the reaction process requires membrane transfer and regeneration, which may damage the integrity of the membrane and introduce defects, making it impossible to achieve true in-situ polymerization.

[0005] Therefore, there is an urgent need to develop a functional thin film that can be rapidly produced, is biocompatible, conductive, ultrathin, has precise morphology preservation, and can be polymerized in situ at biological interfaces for applications such as real-time physiological monitoring, implantable bioelectronics, and organ-on-a-chip. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an ultrathin biomass conductive film and its in-situ rapid preparation method and application. By using a metal ion solution, the problem of film transfer after molding is solved, and high conformity can be achieved for applications with complex curved surfaces and micro / nano structure substrates. It also solves the significant limitations of traditional film preparation methods, such as complex and time-consuming processes and difficulty in rapid completion.

[0007] The technical problem solved by this invention is achieved through the following technical solution:

[0008] A rapid in-situ preparation method for ultrathin biomass conductive films is disclosed. This method utilizes metal ions to form metal coordination bonds with biocompatible biomacromolecule ligands, enabling ultra-rapid in-situ one-step molecular assembly of biomacromolecules. The result is an ultrathin biomass conductive film with high conformability, customizable shape, biodegradability, and low impedance. The steps of the method are as follows:

[0009] S1. Preparation of biomacromolecule precursor solutions: Biomacromolecules are dissolved using direct solvents to obtain biomacromolecule precursor solutions with different solid contents.

[0010] S2. Preparation of metal ion solution: Dissolve the metal ion compound in deionized water to prepare a metal ion solution containing metal ions.

[0011] S3. Preparation of biomass conductive film: A layer of S1 biomacromolecule precursor solution is coated or dipped onto the surface to be film-forming, and then a layer of S2 metal ion solution that can be covered is coated or dipped. The strong coordination bond between the two enables the instantaneous coordination assembly of the biofilm, thus synthesizing an ultrathin biomass conductive film.

[0012] Moreover, the biomacromolecule is selected from one of sodium carboxymethyl cellulose, methyl cellulose, carboxymethyl chitosan, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and ethyl cellulose.

[0013] Furthermore, the metal ion compound is selected from one of copper ion, iron ion, calcium ion, silver ion, and magnesium ion compounds.

[0014] Moreover, the instantaneous coordination assembly time of the biomass conductive film is 1s to 60s.

[0015] Furthermore, the concentration of the biomacromolecule precursor solution in S1 is 0.5 wt% to 20 wt%.

[0016] Furthermore, the molar solubility of the metal ion solution of S2 is 0.5 mol·L⁻¹. -1 ~10mol·L -1 .

[0017] An ultrathin biomass conductive film is prepared using the aforementioned preparation method.

[0018] Application of an ultrathin biomass conductive film in flexible devices.

[0019] The advantages and beneficial effects of this invention are as follows:

[0020] The preparation method of this invention achieves ultra-rapid in-situ one-step molecular assembly of biomolecules by forming metal coordination bonds between metal ions and biocompatible biomolecule ligands, resulting in an ultrathin electronic biomembrane with high conformability, customizable shape, biodegradability, and low impedance. The ultrathin cellulose membrane prepared by this invention has a thin and flexible structure that allows for better contact with biological tissues, reducing the risk of tissue damage and rejection. Its direct formation on the target substrate ensures high conformal contact with any substrate, eliminating the need for additional transfer of soft membranes. Metal complexation gives the epidermal electrons excellent stability. The ultrathin cellulose membrane of this invention has high sensitivity, low impedance, and good skin adhesion, showing great application potential in fields such as electronic skin and medical diagnostics. Attached Figure Description

[0021] Figure 1 This is a flowchart of the present invention;

[0022] Figure 2 This is a schematic diagram showing the ultrathin cellulose membrane prepared in Example 1 of the present invention being attached to different substrates to adapt to the substrate morphology.

[0023] Figure 3 Electron micrograph of the thickness of the ultrathin cellulose membrane prepared in Example 1 of this invention;

[0024] Figure 4 This is a diagram showing the application of the simplified microcircuit of the ultrathin cellulose membrane prepared in Example 1 of the present invention on human skin;

[0025] Figure 5 This is a comparison diagram of the impedance of the ultrathin cellulose membrane prepared in Example 1 of the present invention and a commercial electrode;

[0026] Figure 6 Comparison of electrocardiogram signals collected by commercial electrodes and the ultrathin cellulose membrane prepared in Example 1 of this invention;

[0027] Figure 7 This is a comparison chart of the degradation time of polyethylene plastic and the ultrathin cellulose membrane prepared in Example 1 of this invention. Detailed Implementation

[0028] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0029] Example 1

[0030] like Figure 1 As shown, an in-situ rapid preparation method for ultrathin biomass conductive films is innovative in that the preparation method comprises the following steps:

[0031] 1. Take 2g of sodium carboxymethyl cellulose and add it to 100g of deionized water to prepare a sodium carboxymethyl cellulose solution with a concentration of 2wt%.

[0032] 2. Weigh 67.23g of anhydrous copper chloride and dissolve it in a 1L volumetric flask to obtain a 0.5M copper chloride solution.

[0033] 3. A layer of sodium carboxymethyl cellulose solution is coated on different substrate surfaces. After 1 second, a copper chloride solution that can cover the sodium carboxymethyl cellulose solution layer is coated. The biofilm is synthesized instantaneously, and ultrathin electronic biofilms with high conformability, customizable shape, and low impedance can be obtained rapidly on different substrate surfaces.

[0034] Example 2

[0035] An innovative method for the in-situ rapid preparation of ultrathin biomass conductive films is described, with the following steps:

[0036] 1. Take 1g of methylcellulose and add it to 100g of deionized water to prepare a methylcellulose solution with a concentration of 1wt%.

[0037] 2. Weigh 81.10g of ferric chloride and dissolve it in a 1L volumetric flask to obtain a 0.5M ferric chloride solution.

[0038] 3. Dip a layer of methylcellulose solution onto the surface of the glass slide, and after 1 second, continue to dip it into a ferric chloride solution that can cover the methylcellulose solution layer. The biofilm is synthesized instantaneously, resulting in an ultrathin electronic biofilm with high conformability, customizable shape, and low impedance.

[0039] Example 3

[0040] An innovative method for the in-situ rapid preparation of ultrathin biomass conductive films is described, with the following steps:

[0041] 1. Take 3g of carboxymethyl chitosan and add it to 100g of deionized water to prepare a carboxymethyl chitosan solution with a concentration of 3wt%.

[0042] 2. Weigh 57.80g of anhydrous calcium chloride and dissolve it in a 1L volumetric flask to obtain a 0.5M calcium chloride solution.

[0043] 3. Coat the surface of the glass slide with a layer of carboxymethyl chitosan solution, and after 1 second, continue to coat with calcium chloride solution that can cover the carboxymethyl chitosan solution layer. The biofilm is synthesized instantaneously, resulting in an ultrathin electronic biofilm with high conformability, customizable shape, and low impedance.

[0044] Example 4

[0045] An innovative method for the in-situ rapid preparation of ultrathin biomass conductive films is described, with the following steps:

[0046] 1. Take 2g of sodium carboxymethyl cellulose and add it to 100g of deionized water to prepare a sodium carboxymethyl cellulose solution with a concentration of 2wt%.

[0047] 2. Weigh 85.80g of silver chloride and dissolve it in a 1L volumetric flask to obtain a 0.5M silver chloride solution.

[0048] 3. Dip a layer of carboxymethyl chitosan solution onto the surface of the glass slide, and after 1 second, dip it into a silver chloride solution that can cover the sodium carboxymethyl cellulose solution layer. The biofilm is synthesized instantaneously, resulting in an ultrathin electronic biofilm with high conformability, customizable shape, and low impedance.

[0049] The ultrathin biomass conductive films prepared through the above embodiments have relatively small differences in shape retention, thickness, and degradability. Therefore, Example 1 is used for analysis.

[0050] Figure 2 This is a schematic diagram of the ultrathin biomass conductive film prepared in Example 1 of the present invention, which is adapted to various substrate morphologies and attached to different substrates. It shows that the ultrathin biomass conductive film can meet the high shape retention requirements for application scenarios with complex curved surfaces and micro-nano structure substrates.

[0051] Figure 3 The image shown is a scanning electron microscope image of the thickness of the ultrathin biomass conductive film prepared by Example 1 of this invention. It shows that the thickness is 3.4 μm and it can also be well attached to the wavy template, which indicates that the biomass film has a thin physical structure and ensures that the film can make good contact with the substrate in subsequent applications.

[0052] Figure 4 The conductivity of the biomass membrane was demonstrated; when the membrane was fabricated into a circuit shape, it could simultaneously light up five small light bulbs.

[0053] Figure 5 The results showed that the impedance obtained from the ultrathin biomass conductive film was lower than that of commercial electrodes, indicating that the biomass film has good contact with the skin and good signal conductivity. This will help to obtain high-quality bioelectric signals, reduce signal fluctuations caused by impedance changes during the measurement process, and thus improve the reliability of long-term monitoring.

[0054] Figure 6 The study demonstrated that an ultrathin biomass conductive film was used as an epidermal electrode to collect good electrocardiogram signals, with a signal-to-noise ratio superior to commercially available epidermal electrodes.

[0055] Figure 7 The advantages of ultrathin biomass conductive films in sustainable development were demonstrated. Compared with traditional polyethylene films, biomass films can be completely degraded within nine days, and the biodegradability rate is ≥90% under standard conditions, reflecting the biodegradability of biomass films.

[0056] In summary, the ultrathin biomass conductive film prepared by this invention has a thin and flexible structure, which can be adapted to various substrate morphologies and attached to different substrates; its high sensitivity, low impedance, and good skin adhesion make the biomass film a promising candidate for applications in electronic skin and medical diagnostics.

[0057] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A method for rapid in-situ preparation of ultrathin biomass conductive films, characterized in that: The method utilizes metal ions to form metal coordination bonds with biocompatible biomacromolecule ligands, enabling ultra-rapid in-situ one-step molecular assembly of biomacromolecules, resulting in ultrathin biomass conductive films with high conformability, customizable shape, biodegradability, and low impedance. The steps of the method are as follows: S1. Preparation of biomacromolecule precursor solutions: Biomacromolecules are dissolved using direct solvents to obtain biomacromolecule precursor solutions with different solid contents. S2. Preparation of metal ion solution: Dissolve the metal ion compound in deionized water to prepare a metal ion solution containing metal ions. S3. Preparation of biomass conductive film: A layer of S1 biomacromolecule precursor solution is coated or dipped onto the surface to be film-forming, and then a layer of S2 metal ion solution that can be covered is coated or dipped. The strong coordination bond between the two enables the instantaneous coordination assembly of the biofilm, thus synthesizing an ultrathin biomass conductive film.

2. The method for rapid in-situ preparation of ultrathin biomass conductive films according to claim 1, characterized in that: The biomolecule is selected from one of sodium carboxymethyl cellulose, methyl cellulose, carboxymethyl chitosan, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and ethyl cellulose.

3. The method for rapid in-situ preparation of ultrathin biomass conductive films according to claim 1, characterized in that: The metal ion compound is selected from one of the following: copper ion, iron ion, calcium ion, silver ion, and magnesium ion compounds.

4. The method for in-situ rapid preparation of ultrathin biomass conductive films according to claim 1, characterized in that: The instantaneous coordination assembly time of the biomass conductive film is 1s to 60s.

5. The method for rapid in-situ preparation of ultrathin biomass conductive films according to claim 1, characterized in that: The concentration of the biomacromolecule precursor solution in S1 is 0.5 wt% to 20 wt%.

6. The method for rapid in-situ preparation of ultrathin biomass conductive films according to claim 1, characterized in that: The molar concentration of the metal ion solution of S2 is 0.5 mol·L⁻¹. -1 ~10mol·L -1 .

7. An ultrathin biomass conductive film, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 6.

8. The application of the ultrathin biomass conductive film as described in claim 7 in flexible devices.

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