WO2021143303A1

WO2021143303A1 - Sensor and manufacturing method therefor

Info

Publication number: WO2021143303A1
Application number: PCT/CN2020/126754
Authority: WO
Inventors: 许镇宗; 刘艳花; 黄文彬
Original assignee: 苏州苏大维格科技集团股份有限公司; 苏州大学
Priority date: 2020-01-19
Filing date: 2020-11-05
Publication date: 2021-07-22
Also published as: CN113138039B; CN113138039A

Abstract

The present invention relates to a sensor and a manufacturing method therefor, which can be applied to a wearable device. The sensor comprises a substrate and a sensing layer formed on the substrate, the substrate is provided with a micro-trench forming a micro/nano-pattern, the sensing layer is formed in the micro-trench, and the sensing layer comprises an MXene layer, a CNT layer, and an MXene layer which are of a sandwich structure. The manufacturing method for the sensor comprises: S1, providing a substrate, the substrate being provided with a micro-trench forming a micro/nano-pattern; and S2, preparing a sensing layer, and sequentially forming an MXene layer, a CNT layer, and an MXene layer in the micro-trench. By forming a sensing layer which is of a MXenes-CNT-MXenes sandwich structure in the micro-trench of the substrate, the problem of difficulty in blade-coating a Mxene solution due to the shallow depth of the trench is solved, the conductivity of the sensing layer is also enhanced, and the sensitivity is improved; moreover, the sensor is transparent and stretchable and has a large pressure sensing range.

Description

Sensor and preparation method thereof

This application claims the priority of the Chinese patent application whose application date is January 19, 2020 and the application number is 202010059520.5, the entire content of which is incorporated into this application by reference.

Technical field

The invention relates to a sensor and a preparation method thereof, which can be applied to wearable equipment.

Background technique

With the development of the times, people's demand for flexible wearable smart devices has increased sharply, and the development of pressure sensors with high sensitivity, fast response speed, and simple manufacturing process is the development direction of wearable electronic products. Therefore, finding a new process for flexible array sensors based on micro-nano structures is a problem that needs to be solved urgently today.

Summary of the invention

The purpose of the present invention is to provide a sensor and a preparation method of the sensor, the method is simple to operate, the yield is high, and the sensor has the characteristics of being transparent and stretchable.

In order to achieve the above objective, the present invention provides the following technical solution: a sensor comprising a substrate and a sensing layer formed on the substrate, the substrate has microgrooves forming a micro-nano pattern, and the sensing layer is formed on In the micro groove, the sensing layer includes an MXene layer, a CNT layer, and an MXene layer in a sandwich structure.

Further, the substrate is made of flexible material.

In order to achieve the above objective, the present invention provides the following technical solution: a method for preparing a sensor, including:

S1, providing a substrate, the substrate having micro grooves forming a micro-nano pattern;

S2. Prepare a sensing layer, and sequentially form an MXene layer, a CNT layer and an MXene layer in the micro groove.

Further, the preparation method of the substrate includes:

S11. Use basic silica gel and adhesive to prepare adhesive;

S12. Stir until bubbles appear in the viscous agent;

S13. Put the stirred viscous agent into a vacuum drying oven for vacuuming until the bubbles in the viscous agent disappear;

S14. Coat the vacuumized adhesive on the metal plate with micro-nano pattern;

S15. Put the metal plate coated with the adhesive into a vacuum drying oven to vacuum and cure to form the substrate.

Further, the mass ratio of the base silica gel to the adhesive is 10:1.

Further, the preparation of the sensing layer includes:

S21, providing a first mixed solution of ethanol dissolved in Mxene; performing a first scratch coating on the surface of the substrate, so that the first mixed solution fills the micro grooves;

S22. Put it into a vacuum drying oven for initial curing to form an Mxene layer, to obtain sample one;

S23. Provide a second mixed solution of ethanol in which CNTs are dissolved, and perform a second scratch coating on the surface of the first sample, so that the second mixed solution fills the micro grooves again;

S24. Put it into a vacuum drying oven for secondary curing to form a CNT layer on the Mxene layer to obtain sample two;

S25. Provide the first mixed solution again, and perform a third scratch coating on the surface of the second sample, so that the first mixed solution fills the micro grooves again;

S26. Put it into a vacuum drying oven and perform a third curing to form an Mxene layer on the CNT layer to obtain a sensor.

Further, the mass ratio of Mxene and ethanol used in the first mixed solution is 1:4.

Further, the preparation method of the Mxene is:

The Ti3AlC2 precursor was exfoliated in situ with a hydrochloric acid LiF etchant; the multi-layer MXene exfoliated product was subjected to a deionized moisture layer with ultrasonic deionized water; and a delaminated MXene nanosheet suspension was obtained after centrifugation.

Further, the concentration of the MXene nanosheet suspension is in the range of 0.1-1 mg/mL.

Furthermore, the hydrophilic SWNTs water dispersion is added to the MXene nanosheet suspension and dispersed by ultrasonic components to obtain the MXene nanosheet suspension with the required concentration.

The beneficial effect of the present invention is that by forming the sensing layer of the MXenes-CNT-MXenes sandwich structure in the microgrooves of the substrate, the problem of difficulty in scraping the Mxene solution due to the shallow groove depth is solved, and the sensing is enhanced. The conductivity of the layer improves the sensitivity; and the sensor is transparent, stretchable, and has the characteristics of a large pressure sensing range.

In addition, due to the use of adhesive, it has the characteristics of flexibility and transparency, so the sensor also has the characteristics of transparency, stretchability, and large pressure sensing range.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly and implement it in accordance with the content of the description, the preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Description of the drawings

FIG. 1 is a flowchart of a method for preparing a sensor according to an embodiment of the present invention;

Figure 2 is a flow chart of a method for preparing a substrate;

Figure 3 is a flow chart of the method for preparing the sensing layer.

Detailed ways

The specific implementation of the present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but not to limit the scope of the present invention.

Mxene is a new type of two-dimensional metal transition carbide. Since MXenes was first synthesized, the application of this new type of two-dimensional material in energy storage, electromagnetic interference shielding, transparent conductive electrodes and field effect transistors has made great progress. In addition, a highly flexible and sensitive piezoresistive sensor can be prepared by using the basic characteristics of MXene that the layer spacing changes greatly under the action of external force.

The sensor shown in a preferred embodiment of the present invention includes a substrate and a sensing layer formed on the substrate. The substrate has microgrooves forming a micro-nano pattern, and the sensing layer is formed on the microgrooves. Inside, the sensing layer includes a sandwich structure of MXene layer, carbon nanotube (CNT) layer and MXene layer (ie MXenes-CNT-MXenes sensing layer). In this embodiment, the substrate is made of a flexible material. In detail, the material of the substrate is an adhesive with a mass ratio of basic silica gel to adhesive of 10:1. The basic silica gel can be Sylgard 184 silicone rubber. The adhesive may be a polydimethylsiloxane polymer.

Please refer to Figure 1. The preparation method of the above sensor can adopt the following steps:

S1. Provide a substrate on which microgrooves with micro-nano patterns are formed;

S2. Prepare a sensing layer, and sequentially form an MXene layer, a carbon nanotube (CNT) layer, and an MXene layer (ie, a MXenes-CNT-MXenes sensing layer) in the microgrooves.

Optionally, referring to FIG. 2, the preparation method of the substrate includes:

S11. Adhesive is prepared by using basic silica gel and adhesive. In this embodiment, the mass ratio of the basic silica gel to the adhesive is 10:1, and the adhesive may be a polydimethylsiloxane polymer;

S12. Stir until bubbles appear in the viscous agent;

S14. Coating the vacuum-finished adhesive on a metal plate with a micro-nano pattern. In this embodiment, the metal plate is a nickel plate;

S15. Put the metal plate coated with the adhesive in a vacuum drying oven for vacuum curing, and remove the cured adhesive film sample to form the substrate, and the surface of the substrate has micro grooves forming a micro-nano pattern.

Optionally, the preparation of the sensing layer includes:

In this embodiment, the mass ratio of Mxene and ethanol used in the first mixed solution is 1:4, and the ethanol is anhydrous ethanol.

Optionally, the preparation method of the Mxene is:

The titanium aluminum carbon (Ti3AlC2) precursor was exfoliated in situ with hydrochloric acid LiF etchant; the multi-layer MXene exfoliated product was subjected to deionized moisture layer with ultrasonic deionized water; and the delaminated MXene nanosheet suspension was obtained after centrifugation. Specifically, the concentration of the MXene nanosheet suspension is in the range of 0.1-1 mg/mL. Specifically, an aqueous dispersion of hydrophilic single-walled carbon nanotubes (SWNTs) is added to the MXene nanosheet suspension and dispersed by ultrasonic components to obtain the MXene nanosheet suspension with the required concentration.

The sensing layer of the sensor of this embodiment is an embedded structure. By forming the sensing layer of the MXenes-CNT-MXenes sandwich structure in the micro groove of the substrate, the difficulty of scraping the Mxene solution due to the shallow groove depth is solved, and the CNT layer is added to the sensing layer to enhance The conductive performance of the sensing layer improves the sensitivity; and the adhesive is used to make it flexible and transparent, so the sensor also has the characteristics of transparency, stretchability, and large pressure sensing range, which can effectively expand flexible electronic products The scope of application.

The above preparation steps are described below with detailed examples.

Preparation of flexible substrate

Use a beaker to prepare a viscose with a mass ratio of base silica gel to adhesive of 10:1. The base silica gel can be Sylgard 184 silicone rubber. The adhesive can be polydimethylsiloxane polymer. Stir in a glass cup at room temperature. Until the mixed liquid appears dense and small bubbles, put the stirred viscose into a vacuum drying oven for vacuuming until the bubbles inside the viscose disappear completely, and then pour the vacuumized viscous into the lithography, The nickel plate with micro-pattern array prepared by nano-imprinting and other techniques, then put the nickel plate with spin-coated adhesive into a vacuum drying oven for vacuum curing at 80°C for 1 hour, then take it off and cure it. Flexible substrate.

Preparation of the sensing layer

Prepare MXene suspension, use hydrochloric acid LiF etchant to exfoliate titanium aluminum carbon (Ti3AlC2) precursor in situ; use ultrasonic deionized water to deionize water layer of multi-layer MXene exfoliation product; obtain delaminated MXene after centrifugation Nanosheet suspension, adding hydrophilic SWNTs water dispersion into MXene nanosheet suspension and dispersing by ultrasonic components to obtain the required concentration of MXene nanosheet suspension. The concentration of the MXene nanosheet suspension is in the range of 0.1-1 mg/mL.

Making the first mixed solution: dissolving Mxene and absolute ethanol at a mass ratio of 1:4; making the second mixed solution: dissolving CNT in absolute ethanol;

The detailed steps for making the sensing layer of MXenes-CNT-MXenes are:

Pour the first mixed solution on the surface of the flexible substrate. After sonication, apply the first mixed solution to the surface of the flexible substrate for the first time to make the first mixed solution fill the micro grooves, and then put it into the vacuum drying oven for the first time. Curing to form sample one;

Pour the second mixed solution on the surface of sample one, oscillate uniformly, apply the second mixed solution to the surface of sample one for the second time, make the second mixed solution fill the micro grooves again, and then put it into the vacuum drying oven Perform secondary curing to form the second sample;

Pour the first mixed solution on the second sample, oscillate the first mixed solution evenly, and apply the first mixed solution to the surface of the second sample for the third time to make the second mixed solution fill the micro grooves again, and then put it into the vacuum drying oven for the third time. Three curings are performed to complete the preparation of the sensing layer to obtain a sensor. The sensing layer after the preparation has a sandwich structure of MXenes-CNT-MXenes.

The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and their description is relatively specific and detailed, but they should not be understood as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

A sensor, characterized in that it comprises a substrate and a sensing layer formed on the substrate, the substrate has microgrooves forming a micro-nano pattern, and the sensing layer is formed in the microgrooves, so The sensing layer includes an MXene layer, a CNT layer and an MXene layer in a sandwich structure.
The sensor of claim 1, wherein the substrate is made of a flexible material.
A preparation method of a sensor, characterized in that the preparation method comprises:

S1, providing a substrate, the substrate having micro grooves forming a micro-nano pattern;

S2. Prepare a sensing layer, and sequentially form an MXene layer, a CNT layer and an MXene layer in the micro groove.
8. The method for preparing the sensor according to claim 3, wherein the method for preparing the substrate comprises:

S11. Use basic silica gel and adhesive to prepare adhesive;

S12. Stir until bubbles appear in the viscous agent;

S13. Put the stirred viscous agent into a vacuum drying oven for vacuuming until the bubbles in the viscous agent disappear;

S14. Coat the vacuumized adhesive on the metal plate with micro-nano pattern;

S15. Put the metal plate coated with the adhesive into a vacuum drying oven to vacuum and cure to form the substrate.
The method for preparing the sensor according to claim 4, wherein the mass ratio of the base silica gel to the adhesive is 10:1.
8. The method for manufacturing the sensor according to claim 3, wherein the preparation of the sensing layer comprises:

S21, providing a first mixed solution of ethanol dissolved in Mxene; performing a first scratch coating on the surface of the substrate, so that the first mixed solution fills the micro grooves;

S22. Put it into a vacuum drying oven for initial curing to form an Mxene layer, to obtain sample one;

S23. Provide a second mixed solution of ethanol in which CNTs are dissolved, and perform a second scratch coating on the surface of the first sample, so that the second mixed solution fills the micro grooves again;

S24. Put it into a vacuum drying oven for secondary curing to form a CNT layer on the Mxene layer to obtain sample two;

S25. Provide the first mixed solution again, and perform a third scratch coating on the surface of the second sample, so that the first mixed solution fills the micro grooves again;

S26. Put it into a vacuum drying oven and perform a third curing to form an Mxene layer on the CNT layer to obtain a sensor.
7. The method for preparing the sensor according to claim 6, wherein the mass ratio of Mxene and ethanol used in the first mixed solution is 1:4.
8. The method for preparing the sensor according to claim 6, wherein the method for preparing Mxene is:

The Ti3AlC2 precursor was exfoliated in situ with a hydrochloric acid LiF etchant; the multi-layer MXene exfoliated product was subjected to a deionized moisture layer with ultrasonic deionized water; and a delaminated MXene nanosheet suspension was obtained after centrifugation.
8. The method for preparing the sensor according to claim 8, wherein the concentration of the MXene nanosheet suspension is in the range of 0.1-1 mg/mL.
9. The method for preparing the sensor according to claim 9, characterized in that a hydrophilic SWNTs water dispersion is added to the MXene nanosheet suspension and dispersed by ultrasonic components to obtain the MXene nanosheet suspension with the required concentration.