CN113517388B - A kind of degradable piezoelectric energy harvester and preparation method thereof - Google Patents

Abstract

The invention relates to a degradable piezoelectric energy collector and a preparation method thereof, wherein the preparation method comprises the steps of growing a piezoelectric biomaterial array on a substrate; preparing a degradable film on a substrate, so that the degradable film coats the piezoelectric biomaterial array; stripping the degradable film coated with the piezoelectric biomaterial array from the substrate to obtain a degradable piezoelectric layer; preparing two degradable electrodes, wherein the degradable electrodes comprise a degradable substrate layer and a metal layer which are arranged in a laminated manner; the degradable piezoelectric layer is placed between two degradable electrodes, and the degradable piezoelectric energy collector is formed by bonding, and the metal layer is positioned on one side close to the degradable piezoelectric layer. According to the preparation method, the piezoelectric biological material array with the single growth direction and polarization direction is peeled off from the hard substrate, and the degradable and biocompatible material is used as the electrode and the packaging material of the degradable piezoelectric energy collector, so that the prepared piezoelectric energy collector has degradability and biocompatibility.

Description

A kind of degradable piezoelectric energy harvester and preparation method thereof

Technical field

The invention belongs to the technical field of energy collectors, and specifically relates to a degradable piezoelectric energy collector and a preparation method thereof.

Background technique

A piezoelectric energy collector is an energy conversion device based on piezoelectric materials. It can effectively convert mechanical energy (such as blue energy, wind energy, sound energy, and biological movement, etc.) into secondary energy that can be used again. Electric energy is considered to be the most promising type of green energy, and nanogenerators that can perform electromechanical conversion provide a new solution for continuous energy supply.

The piezoelectric effect exists in many materials with non-centrosymmetric crystal structures, especially ceramic materials. Although it has a high piezoelectric constant, its natural brittleness causes ceramic materials to be easily damaged under the action of force, limiting the its application in flexible electronic devices. Although the flexibility can be increased by using nanoribbons, nanowires, etc. after process improvement, the synthesis temperature is relatively high, and ceramic materials usually contain bioincompatible elements, making most current piezoelectric energy harvesters not fully reliable. Degradation characteristics and biocompatibility limit its application in the field of implantable electronic devices.

Contents of the invention

In order to solve the above problems existing in the prior art, the present invention provides a degradable piezoelectric energy collector and a preparation method thereof. The technical problems to be solved by the present invention are achieved through the following technical solutions:

The invention provides a method for preparing a degradable piezoelectric energy collector, which includes:

growing an array of piezoelectric biomaterials on a substrate;

Preparing a degradable film on the substrate so that the degradable film coats the piezoelectric biomaterial array;

Peeling the degradable film covering the piezoelectric biomaterial array from the substrate to obtain a degradable piezoelectric layer;

Preparing two degradable electrodes, the degradable electrodes including a stacked degradable substrate layer and a metal layer;

The degradable piezoelectric layer is placed between the two degradable electrodes and bonded to form a degradable piezoelectric energy collector. The metal layer is located on the side close to the degradable piezoelectric layer.

In one embodiment of the invention, the piezoelectric biomaterial array has a single growth direction and polarization direction.

In one embodiment of the present invention, the material of the piezoelectric biomaterial array is one or more of peptides, amino acids, and cellulose.

In one embodiment of the invention, growing a piezoelectric biomaterial array on a substrate includes:

growing a biomaterial array on a substrate, the biomaterial array being perpendicular to the substrate;

An electric field parallel to the growth direction of the biomaterial array is applied to achieve a single polarization direction to obtain a piezoelectric biomaterial array.

In one embodiment of the present invention, the electric field intensity is -10KV ~ 10KV.

In one embodiment of the present invention, a degradable film is prepared on the substrate so that the degradable film covers the piezoelectric biomaterial array, including:

A degradable solution is spin-coated on the substrate on which the piezoelectric biomaterial array is grown, so that the degradable solution completely covers the piezoelectric biomaterial array, and after drying, a degradable solution covering the piezoelectric biomaterial array is formed. Degradable film.

In one embodiment of the present invention, the material of the degradable film and the degradable substrate layer is one of polylactic acid, silk fibroin, polyglycolic acid, polyε-caprolactone or polyhydroxybutyrate. kind.

In one embodiment of the present invention, the thickness of the degradable substrate layer is 0.2-0.4mm.

The present invention also provides a degradable piezoelectric energy collector, which is prepared by the preparation method as described in any one of the above embodiments. The degradable piezoelectric energy collector includes: arranged in sequence from bottom to top. The first degradable electrode, the degradable piezoelectric layer and the second degradable electrode, wherein,

The first degradable electrode and the second degradable electrode both include a degradable substrate layer and a metal layer arranged in a stack, and the metal layer is located on a side close to the degradable piezoelectric layer;

The degradable piezoelectric layer includes a piezoelectric biomaterial array and a degradable film covering the piezoelectric biomaterial array. The piezoelectric biomaterial array has a single growth direction and polarization direction.

In one embodiment of the present invention, the material of the piezoelectric biomaterial array is one or more of peptides, amino acids, and cellulose;

The material of the degradable film and the degradable substrate layer is one of polylactic acid, silk fibroin, polyglycolic acid, polyε-caprolactone or polyhydroxybutyrate.

Compared with the prior art, the beneficial effects of the present invention are:

The preparation method of the degradable piezoelectric energy collector of the present invention peels off the piezoelectric biomaterial array with a single growth direction and polarization direction from the hard substrate, and uses degradable and biocompatible materials as the degradable piezoelectric energy collector. The electrodes and packaging materials of the energy harvester make the prepared piezoelectric energy harvester degradable and biocompatible, which greatly expands the application range of piezoelectric energy harvesters, especially in the biomedical field.

The above description is only an overview of the technical solution of the present invention. In order to have a clearer understanding of the technical means of the present invention, it can be implemented according to the content of the description, and in order to make the above and other objects, features and advantages of the present invention more obvious and understandable. , the following is a detailed description of the preferred embodiments, together with the accompanying drawings.

Description of the drawings

Figure 1 is a schematic diagram of a preparation method of a degradable piezoelectric energy collector provided by an embodiment of the present invention;

Figures 2a-2f are process flow diagrams of a method for preparing a degradable piezoelectric energy harvester provided by an embodiment of the present invention;

Figure 3 is a schematic structural diagram of a degradable piezoelectric energy collector provided by an embodiment of the present invention;

Figure 4 is an electrical performance diagram of a degradable piezoelectric energy collector provided by an embodiment of the present invention;

Figure 5 is a picture of the degradation process of a degradable piezoelectric energy collector provided by an embodiment of the present invention.

Detailed ways

In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended inventive purpose, a degradable piezoelectric energy harvester and its preparation method proposed according to the present invention will be described in detail below in conjunction with the drawings and specific embodiments.

The foregoing and other technical contents, features and effects of the present invention can be clearly presented in the following detailed description of the specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, we can have a more in-depth and specific understanding of the technical means and effects adopted by the present invention to achieve the intended purpose. However, the attached drawings are only for reference and illustration, and are not used to explain the technical aspects of the present invention. program is restricted.

Embodiment 1

Please refer to Figure 1. Figure 1 is a schematic diagram of a method for preparing a degradable piezoelectric energy harvester provided by an embodiment of the present invention. As shown in the figure, the preparation method of this embodiment includes:

S1: Growth of piezoelectric biomaterial arrays on substrates;

In this embodiment, the piezoelectric biomaterial array has a single growth direction and polarization direction, and the material of the piezoelectric biomaterial array is one or more of peptides, amino acids, and cellulose. The substrate is usually a hard substrate, such as silicon wafer.

It should be noted that in this embodiment, a hard substrate is selected and a piezoelectric biomaterial array is prepared on it and then peeled off, instead of directly preparing a piezoelectric biomaterial array on a degradable film, because the surface of the hard substrate is relatively thin. Smoothness is conducive to the growth of piezoelectric biomaterial arrays, but the surface of the degradable film is uneven and cannot grow an array in a single direction. Secondly, the solvent used in the growth process will corrode the degradable film.

Specifically, S1 includes:

S11: Grow the biomaterial array on the substrate, and the biomaterial array is perpendicular to the substrate;

Alternatively, an array of biomaterials perpendicular to the substrate is grown on the substrate by epitaxial growth.

S12: Apply an electric field parallel to the growth direction of the biomaterial array to achieve a single polarization direction to obtain a piezoelectric biomaterial array.

In this embodiment, the direction of the external electric field is the vertical direction, and the electric field intensity is -10KV~10KV.

S2: Prepare a degradable film on the substrate so that the degradable film coats the piezoelectric biomaterial array;

Specifically, the method includes: spin-coating a degradable solution on a substrate on which a piezoelectric biomaterial array is grown, so that the degradable solution completely covers the piezoelectric biomaterial array, and after drying, a degradable film covering the piezoelectric biomaterial array is formed.

In this embodiment, the material of the degradable membrane is one of polylactic acid, silk fibroin, polyglycolic acid, polyε-caprolactone or polyhydroxybutyrate.

Taking polylactic acid as an example, the configuration of the degradable solution is explained. Specifically, the polylactic acid is put into the chloroform solution, stirred with a magnetic stirrer for 30 minutes, and a polylactic acid solution with a concentration of 50 mg/mL is prepared.

Optionally, the spin coating speed of the degradable solution is 2000rad/ _s -4000rad/ _s .

S3: Peel off the degradable film covering the piezoelectric biomaterial array from the substrate to obtain a degradable piezoelectric layer;

In this embodiment, the degradable film covering the piezoelectric biomaterial array is slowly peeled off from the substrate manually.

S4: Prepare two degradable electrodes. The degradable electrodes include a stacked degradable substrate layer and a metal layer;

In this embodiment, the material of the degradable substrate layer is one of polylactic acid, silk fibroin, polyglycolic acid, polyε-caprolactone or polyhydroxybutyrate. The material of the metal layer is one of magnesium, molybdenum, zinc or titanium.

Optionally, the thickness of the degradable substrate layer is 0.2-0.4mm.

Specifically, the method includes: first preparing a degradable solution, pouring the degradable solution into a vessel to form a film to obtain a degradable substrate layer, and then thermally evaporating metal on the degradable substrate layer to prepare a degradable electrode.

S5: Place the degradable piezoelectric layer between two degradable electrodes and bond them to form a degradable piezoelectric energy collector. The metal layer is located on the side close to the degradable piezoelectric layer.

In this embodiment, the degradable solution serves as an adhesive to bond the degradable piezoelectric layer and the two degradable electrodes together to form a sandwich structure. The degradable substrate layer serves as the encapsulation layer of the degradable piezoelectric energy collector.

It should be noted that since the degradable piezoelectric layer and the degradable electrode are prepared separately, the preparation sequence is not limited here. The degradable electrode can also be prepared first, and then the degradable piezoelectric layer can be prepared.

The preparation method of the degradable piezoelectric energy collector in this embodiment is to peel off the piezoelectric biomaterial array with a single growth direction and polarization direction from the hard substrate, and use degradable and biocompatible materials as the degradable piezoelectric energy harvester. The electrodes and packaging materials of the electrical energy harvester make the prepared piezoelectric energy harvester degradable and biocompatible, which greatly expands the application range of piezoelectric energy harvesters, especially in the biomedical field.

Embodiment 2

Taking polylactic acid as a degradable film and a degradable substrate layer as an example, the preparation method in Embodiment 1 will be described in detail. Please refer to Figures 2a to 2f. Figures 2a to 2f are a degradable film provided by the embodiment of the present invention. Flowchart of a method for preparing a piezoelectric energy harvester. The method includes the following steps:

Step 1: Grow the phenylalanine dipeptide array 202 perpendicular to the silicon wafer on the silicon wafer 201 by epitaxial growth method, as shown in Figure 2a;

Step 2: Apply an electric field parallel to the growth direction of the phenylalanine dipeptide array 202, and the applied electric field intensity is 8.5KV, as shown in Figure 2b;

Step 3: Spin-coat the degradable solution on the silicon wafer 201 so that the degradable solution completely covers the phenylalanine dipeptide array. After drying, a degradable film 203 covering the phenylalanine dipeptide array is formed, as shown in Figure 2c. shown;

Specifically, the spin coating speed is 2000rad/s, and the degradable solution preparation method is to put the polylactic acid into the chloroform solution and stir it with a magnetic stirrer for 30 minutes. The concentration of the degradable polylactic acid solution is 50 mg/mL.

Step 4: Slowly peel off the degradable film 203 covering the phenylalanine dipeptide array 202 from the silicon substrate 201 to obtain a degradable piezoelectric layer, as shown in Figure 2d;

The prepared degradable membrane can completely wrap the phenylalanine dipeptide array, so that the structure of the phenylalanine dipeptide array will not be damaged during the peeling process.

Step 5: Pour the degradable polylactic acid solution into a vessel to form a film to obtain a degradable substrate layer 204. A metal molybdenum layer 205 is thermally evaporated on the degradable substrate layer to prepare a degradable electrode, as shown in Figure 2e;

Step 6: Place the degradable piezoelectric layer in the middle, with degradable electrodes coated with metal molybdenum above and below it. Use polylactic acid as an adhesive to bond the upper and lower degradable electrodes and the degradable piezoelectric layer together. The degradable piezoelectric energy harvester is assembled, as shown in Figure 2f.

Embodiment 3

This embodiment provides a degradable piezoelectric energy harvester, which is prepared by the preparation method described in the above embodiment. Please refer to Figure 3. Figure 3 is a degradable piezoelectric energy harvester provided by an embodiment of the present invention. Schematic diagram of the structure of the device. As shown in the figure, the degradable piezoelectric energy collector includes: a first degradable electrode 301, a degradable piezoelectric layer 302 and a second degradable electrode 303 arranged in sequence from bottom to top.

Wherein, the first degradable electrode 301 and the second degradable electrode 303 both include a stacked degradable substrate layer 30 and a metal layer 31, and the metal layer 31 is located on the side close to the degradable piezoelectric layer 302. The degradable piezoelectric layer 302 includes a piezoelectric biomaterial array 3021 and a degradable film 3022 covering the piezoelectric biomaterial array 3021. The piezoelectric biomaterial array 3021 columns have a single growth direction and polarization direction.

In this embodiment, the material of the piezoelectric biomaterial array 3021 is one or more of peptides, amino acids, and cellulose. The material of the degradable membrane 3022 and the degradable substrate layer 30 is one of polylactic acid, silk fibroin, polyglycolic acid, polyε-caprolactone or polyhydroxybutyrate.

It should be noted that the degradable substrate layer 30 also serves as an encapsulation layer of the degradable piezoelectric energy collector.

The degradable piezoelectric energy collector of this embodiment uses degradable and biocompatible materials as the electrodes and packaging materials of the degradable piezoelectric energy collector, so that the piezoelectric energy collector has degradability and biocompatibility. , greatly expanding the application scope of piezoelectric energy harvesters, especially in the biomedical field.

Please refer to Figure 4. Figure 4 is an electrical performance diagram of a degradable piezoelectric energy collector provided by an embodiment of the present invention. The materials of the degradable film 3022 and the degradable substrate layer 30 of the degradable piezoelectric energy collector are both Polylactic acid is used. The picture (a) shows the open circuit voltage diagram generated by the degradable piezoelectric energy collector under the action of external force. The picture (b) shows the short circuit current diagram generated by the degradable piezoelectric energy collector under the action of external force. It can be seen from the figure that under the action of external force, the open circuit voltage and short circuit current generated by the degradable piezoelectric energy harvester are 1.2V and 40nA respectively.

Further, please refer to FIG. 5 , which is a picture of the degradation process of a degradable piezoelectric energy collector provided by an embodiment of the present invention. The degradable piezoelectric energy collector's degradable film 3022 and the degradable substrate layer 30 are both made of polylactic acid. The degradable piezoelectric energy collector is completely immersed in a phosphate buffer solution and placed at a constant temperature of 37°C. In the box, observe its degradation characteristics. As shown in the figure, they are the first day ((a) in Figure 5) and the 180th day when the degradable piezoelectric energy collector of this embodiment is soaked in the phosphate buffer solution. It can be seen from the photo of the day ((b) in Figure 5) that on the 180th day, the degradable piezoelectric energy collector of this embodiment is basically completely degraded.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations are mutually exclusive. any such actual relationship or sequence exists between them. Furthermore, the terms "comprises," "comprises," or any other variation are intended to cover a non-exclusive inclusion, such that an article or device including a list of elements includes not only those elements, but also other elements not expressly listed. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in an article or device including the stated element. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The orientations or positional relationships indicated by "upper", "lower", "left", "right", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying The devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation and therefore are not to be construed as limitations of the invention.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be concluded that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all of them should be regarded as belonging to the protection scope of the present invention.

Claims (5)

1. A method of making a degradable piezoelectric energy harvester comprising:

growing an array of piezoelectric biological materials on a substrate; comprising the following steps:

growing an array of biological materials on a substrate, the array of biological materials being perpendicular to the substrate;

applying an electric field parallel to the growth direction of the biological material array to realize a single polarization direction to obtain a piezoelectric biological material array;

the piezoelectric biological material array has a single growth direction and polarization direction, the material of the piezoelectric biological material array is one or more of peptide, amino acid and cellulose, and the substrate is a hard substrate;

preparing a degradable film on the substrate, so that the degradable film coats the piezoelectric biomaterial array;

peeling the degradable film coated with the piezoelectric biomaterial array from the substrate to obtain a degradable piezoelectric layer;

preparing two degradable electrodes, wherein the degradable electrodes comprise a degradable substrate layer and a metal layer which are arranged in a laminated manner;

placing the degradable piezoelectric layer between two degradable electrodes, and bonding to form a degradable piezoelectric energy collector, wherein the metal layer is positioned at one side close to the degradable piezoelectric layer, and a degradable solution is used as an adhesive to bond the degradable piezoelectric layer and the two degradable electrodes together to form a sandwich structure;

wherein the degradable film and the degradable substrate layer are made of one of polylactic acid, silk fibroin, polyglycolic acid, poly epsilon-caprolactone or polyhydroxybutyrate.

2. The method of claim 1, wherein the electric field strength is-10 KV.

3. The method of manufacturing a degradable piezoelectric energy harvester of claim 1 wherein manufacturing a degradable film on the substrate such that the degradable film encapsulates the array of piezoelectric biological materials comprises:

and spin-coating a degradable solution on the substrate on which the piezoelectric biomaterial array grows, so that the degradable solution completely covers the piezoelectric biomaterial array, and forming a degradable film coating the piezoelectric biomaterial array after drying.

4. The method of manufacturing a degradable piezoelectric energy harvester of claim 1 wherein the thickness of the degradable substrate layer is 0.2-0.4mm.

5. A degradable piezoelectric energy harvester prepared by the method of any one of claims 1-4, comprising: a first degradable electrode, a degradable piezoelectric layer and a second degradable electrode which are sequentially arranged from bottom to top,

the first degradable electrode and the second degradable electrode comprise a degradable substrate layer and a metal layer which are arranged in a stacked manner, and the metal layer is positioned on one side close to the degradable piezoelectric layer;

the degradable piezoelectric layer comprises a piezoelectric biological material array and a degradable film coating the piezoelectric biological material array, and the piezoelectric biological material array has a single growth direction and polarization direction;

the piezoelectric biological material array is made of one or more of peptide, amino acid and cellulose;

the degradable film and the degradable substrate layer are made of one of polylactic acid, silk fibroin, polyglycolic acid, poly epsilon-caprolactone or polyhydroxybutyrate.