CN115725181A - Porous dielectric material, preparation method thereof and flexible capacitive pressure sensor - Google Patents
Porous dielectric material, preparation method thereof and flexible capacitive pressure sensor Download PDFInfo
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- CN115725181A CN115725181A CN202211377309.3A CN202211377309A CN115725181A CN 115725181 A CN115725181 A CN 115725181A CN 202211377309 A CN202211377309 A CN 202211377309A CN 115725181 A CN115725181 A CN 115725181A
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Abstract
The invention discloses a porous dielectric material, a preparation method thereof and a flexible capacitive pressure sensor. The composition of the porous dielectric material comprises a polymer matrix and ceramic nanowires, wherein the ceramic nanowires are distributed in the polymer matrix and on the surface of the polymer matrix, and a plurality of holes are distributed in the porous dielectric material and on the surface of the porous dielectric material. The preparation method of the porous dielectric material comprises the following steps: and uniformly mixing the polymer matrix material, the ceramic nanowires and the polymer microspheres to prepare a film, and dissolving to remove the polymer microspheres in the film to obtain the porous dielectric material. The porous dielectric material has the advantages of large elasticity, good dielectric property, simple preparation process and the like, and the flexible capacitive pressure sensor prepared from the porous dielectric material has the advantages of high sensitivity, wide detection range and the like, and is suitable for large-scale industrial application.
Description
Technical Field
The invention relates to the technical field of sensors, in particular to a porous dielectric material, a preparation method thereof and a flexible capacitive pressure sensor.
Background
The capacitive pressure sensor changes the thickness of the dielectric layer by applying pressure, so that the dielectric layer generates capacitance change, the capacitance change is converted into an electric signal, and finally the pressure is determined by the electric signal.
In recent years, with the rapid development of wearable devices, electronic skins, and other fields, there is a great demand for flexible capacitive pressure sensors having excellent mechanical and electrical properties. The dielectric layer is an important optimization object for improving the sensitivity, the pressure response range and the like of the capacitive pressure sensor, and the dielectric layer in the conventional flexible capacitive pressure sensor is usually made of a polymer material, so that the dielectric layer is limited in elasticity and poor in dielectric property, the dielectric layer is not beneficial to deformation along with the change of stress action, and the sensitivity and the detection range of the flexible capacitive pressure sensor are influenced finally.
Therefore, the development of a porous dielectric material with high elasticity and good dielectric property and a flexible capacitive pressure sensor with high sensitivity and wide detection range have very important significance.
Disclosure of Invention
The invention aims to provide a porous dielectric material, a preparation method thereof and a flexible capacitive pressure sensor.
The technical scheme adopted by the invention is as follows:
a porous dielectric material having a composition comprising a polymer matrix and ceramic nanowires; the ceramic nanowires are distributed in the polymer matrix and on the surface of the polymer matrix; a plurality of holes are distributed in the porous dielectric material and on the surface of the porous dielectric material.
Preferably, the porosity of the porous dielectric material is 50% to 80%.
Preferably, the polymer matrix is composed of at least one of polydimethylsiloxane, polyurethane, polyimide and polyvinyl alcohol.
Further preferably, the polymer matrix consists of polydimethylsiloxane.
Preferably, the ceramic nanowire is at least one of a lead zirconate titanate nanowire, a zirconium oxide nanowire, a barium titanate nanowire, a zinc oxide nanowire, an aluminum oxide nanowire and a silicon carbide nanowire.
Further preferably, the ceramic nanowire is a lead zirconate titanate nanowire.
Preferably, the length of the ceramic nanowire is 5-50 μm, and the diameter is 10-50 nm.
Preferably, the ceramic nanowires are subjected to surface modification by using a silane coupling agent.
Preferably, the addition amount of the ceramic nanowires is 3-20% of the mass of the polymer matrix.
A method of preparing a porous dielectric material as described above comprises the steps of: and uniformly mixing the polymer matrix material, the ceramic nanowires and the polymer microspheres to prepare a film, and dissolving to remove the polymer microspheres in the film to obtain the porous dielectric material.
Preferably, a method for preparing a porous dielectric material as described above comprises the steps of: and mixing and dispersing the polymer matrix material, the ceramic nanowires and the polymer microspheres in an organic solvent, coating the mixture on a substrate, drying to form a film, soaking the obtained film in a solvent capable of dissolving the polymer microspheres to remove the polymer microspheres in the film, and thus obtaining the porous dielectric material.
Preferably, the volume ratio of the polymer matrix material to the polymer microspheres is 1.
Preferably, the polymer microspheres are at least one of polystyrene microspheres, silica microspheres, melamine resin microspheres, polyvinyl toluene microspheres and polymethacrylate microspheres.
Further preferably, the polymer microspheres are polystyrene microspheres.
Preferably, the diameter of the polymer microsphere is 1-10 μm.
Preferably, the organic solvent is at least one of isopropanol, glycerol, acetic acid and acetonitrile.
Preferably, the solvent capable of dissolving the polymer microspheres is at least one of N, N-dimethylformamide, N-methylpyrrolidone, ethyl acetate and ether solvents.
A flexible capacitive pressure sensor comprises the porous dielectric material.
Preferably, the flexible capacitive pressure sensor comprises a flexible substrate, a dielectric layer, a first electrode layer and a second electrode layer; the dielectric layer and the first electrode layer are arranged on the same surface of the flexible substrate; the second electrode layer is arranged on the side, far away from the flexible substrate, of the dielectric layer; the composition of the dielectric layer comprises the porous dielectric material.
Preferably, the flexible substrate is one of a flexible polyethylene terephthalate (PET) substrate, a flexible Polyimide (PI) substrate, a flexible polyethylene naphthalate (PEN) substrate, a flexible Polycarbonate (PC) substrate, a flexible Polyethersulfone (PES) substrate, a flexible Polycycloolefin (PCO) substrate, a flexible Polyarylate (PAR) substrate, a flexible Polydimethylsiloxane (PDMS) substrate, and a flexible Polyurethane (PU) substrate.
The invention has the beneficial effects that: the porous dielectric material has the advantages of large elasticity, good dielectric property, simple preparation process and the like, and the flexible capacitive pressure sensor prepared from the porous dielectric material has the advantages of high sensitivity, wide detection range and the like, and is suitable for large-scale industrial application.
Specifically, the method comprises the following steps:
1) The porous dielectric material has a three-dimensional porous structure, and a dielectric layer prepared from the porous dielectric material has high porosity, is easier to deform under the action of stress and has excellent elastic performance;
2) The porous dielectric material is filled with a ceramic material with high dielectric constant and high length-diameter ratio, and the flexible capacitive pressure sensor obtained by manufacturing the porous dielectric material into a dielectric layer and then assembling the dielectric layer has high sensitivity and wide detection range.
Drawings
FIG. 1 is an SEM image of a porous dielectric material of example 1.
Fig. 2 is a schematic structural diagram of the flexible capacitive pressure sensor of the present invention.
Description of the figures: 10. a flexible substrate; 20. a dielectric layer; 30. a first electrode layer; 40. a second electrode layer.
FIG. 3 is an SEM image of a porous dielectric material of example 2.
FIG. 4 is an SEM image of a porous dielectric material of example 4.
Fig. 5 is a pressure response curve of the flexible capacitive pressure sensors of examples 1 to 4 and comparative example.
Fig. 6 is a test result chart of the flexible capacitive pressure sensor of example 3 for testing the pulse of different people.
Detailed Description
The invention will be further explained and illustrated with reference to specific examples.
Example 1:
a porous dielectric material, the preparation method of which comprises the following steps:
1) Ultrasonically dispersing polydimethylsiloxane (a main agent in a Dow Corning Sylgard 184), lead zirconate titanate nanowires (the length is 5-50 mu m, the diameter is 10-50 nm, and the surface modification is carried out by using a coupling agent KH-550) and polystyrene microspheres (the diameter is 1-10 mu m) in isopropanol, wherein the volume ratio of the polydimethylsiloxane to the polystyrene microspheres is 1;
2) Adding a curing agent (the curing agent in the Dow Corning Sylgard 184) into the mixture obtained in the step 1), wherein the volume ratio of polydimethylsiloxane to the curing agent is 8;
3) Uniformly coating the coating mixture obtained in the step 2) on a glass substrate by using a scraper, and heating and curing for 3 hours at 70 ℃ to obtain a film;
4) And (4) removing the film in the step 3) from the substrate, soaking the substrate in N, N-dimethylformamide for 12 hours, taking out the substrate and drying the substrate to obtain the porous dielectric material (the porosity is 75%, and the SEM image is shown in figure 1).
A flexible capacitive pressure sensor (the schematic structural diagram is shown in FIG. 2) comprises a flexible substrate 10, a dielectric layer 20, a first electrode layer 30 and a second electrode layer 40, wherein the dielectric layer 20 and the first electrode layer 30 are arranged on the same surface of the flexible substrate 10, the second electrode layer 40 is arranged on the surface of the dielectric layer 20 far away from the flexible substrate 10, the flexible substrate 10 is a flexible PET substrate, and the dielectric layer 20 is made of the porous dielectric material of the embodiment.
Note:
the porosity is calculated with reference to the following formula: p 0 ＝V a /(V a +V b ) X100%, wherein P 0 Porosity, V, of porous dielectric material a Volume of polystyrene microsphere, V b Volume of polydimethylsiloxane.
Example 2:
a porous dielectric material, the preparation method of which comprises the following steps:
1) Ultrasonically dispersing polydimethylsiloxane (a main agent in a Dow Corning Sylgard 184), lead zirconate titanate nanowires (the length is 5-50 mu m, the diameter is 10-50 nm, and the surface modification is carried out by using a coupling agent KH-550) and polystyrene microspheres (the diameter is 1-10 mu m) in isopropanol, wherein the volume ratio of the polydimethylsiloxane to the polystyrene microspheres is 1;
2) Adding a curing agent (the curing agent in Sylgard184 Dow Corning) into the mixture obtained in the step 1), wherein the volume ratio of polydimethylsiloxane to the curing agent is 8;
3) Uniformly coating the coating mixture obtained in the step 2) on a glass substrate by using a scraper, and heating and curing for 3 hours at 70 ℃ to obtain a film;
4) Removing the film obtained in the step 3) from the substrate, soaking the substrate in N, N-dimethylformamide for 12h, taking out the substrate, and drying to obtain the porous dielectric material (with the porosity of 75%, and the SEM image is shown in figure 3).
A flexible capacitive pressure sensor substantially as described in example 1, except that the composition of the dielectric layer 20 was changed to the porous dielectric material of this example.
Example 3:
a porous dielectric material is prepared by a method comprising the steps of:
1) Ultrasonically dispersing polydimethylsiloxane (a main agent in a Dow Corning Sylgard 184), lead zirconate titanate nanowires (the length is 5-50 mu m, the diameter is 10-50 nm, and the surface modification is carried out by using a coupling agent KH-550) and polystyrene microspheres (the diameter is 1-10 mu m) in isopropanol, wherein the volume ratio of the polydimethylsiloxane to the polystyrene microspheres is 1;
2) Adding a curing agent (the curing agent in the Dow Corning Sylgard 184) into the mixture obtained in the step 1), wherein the volume ratio of polydimethylsiloxane to the curing agent is 8;
3) Uniformly coating the coating mixture obtained in the step 2) on a glass substrate by using a scraper, and heating and curing for 3 hours at 70 ℃ to obtain a film;
4) Removing the film obtained in the step 3) from the substrate, soaking the substrate in N, N-dimethylformamide for 12h, taking out the substrate and drying the substrate to obtain the porous dielectric material (with the porosity of 75%).
A flexible capacitive pressure sensor substantially as in example 1 except that the composition of the dielectric layer 20 was changed to the porous dielectric material of this example.
Example 4:
a porous dielectric material, the preparation method of which comprises the following steps:
1) Ultrasonically dispersing polydimethylsiloxane (a main agent in a Dow Corning Sylgard 184), lead zirconate titanate nanowires (the length is 5-50 mu m, the diameter is 10-50 nm, and the surface modification is carried out by using a coupling agent KH-550) and polystyrene microspheres (the diameter is 1-10 mu m) in isopropanol, wherein the volume ratio of the polydimethylsiloxane to the polystyrene microspheres is 1;
2) Adding a curing agent (the curing agent in the Dow Corning Sylgard 184) into the mixture obtained in the step 1), wherein the volume ratio of polydimethylsiloxane to the curing agent is 8;
3) Uniformly coating the coating mixture obtained in the step 2) on a glass substrate by using a scraper, and heating and curing for 3 hours at 70 ℃ to obtain a film;
4) And (4) removing the film in the step 3) from the substrate, soaking the substrate in N, N-dimethylformamide for 12 hours, taking out the substrate and drying the substrate to obtain the porous dielectric material (the porosity is 75%, and an SEM image is shown in figure 4).
A flexible capacitive pressure sensor substantially as in example 1 except that the composition of the dielectric layer 20 was changed to the porous dielectric material of this example.
Comparative example:
a porous dielectric material is prepared by a method comprising the steps of:
1) Ultrasonically dispersing polydimethylsiloxane (a main agent in Dow Corning Sylgard 184) and polystyrene microspheres (the diameter is 1-10 mu m) in isopropanol, wherein the volume ratio of the polydimethylsiloxane to the polystyrene microspheres is 1;
2) Adding a curing agent (the curing agent in the Dow Corning Sylgard 184) into the mixture obtained in the step 1), wherein the volume ratio of polydimethylsiloxane to the curing agent is 8;
3) Uniformly coating the coating mixture obtained in the step 2) on a glass substrate by using a scraper, and heating and curing for 3 hours at 70 ℃ to obtain a film;
4) Removing the film obtained in the step 3) from the substrate, soaking the substrate in N, N-dimethylformamide for 12h, taking out the substrate and drying the substrate to obtain the porous dielectric material (with the porosity of 75%).
A flexible capacitive pressure sensor substantially as in example 1 except that the composition of the dielectric layer 20 is replaced with the porous dielectric material of the comparative example.
And (3) performance testing:
1) The pressure response curves of the flexible capacitive pressure sensors of examples 1 to 4 and comparative example are shown in fig. 5.
As can be seen from fig. 5: the pressure responsiveness of the flexible capacitive pressure sensor is increased along with the increase of the doping proportion of the lead zirconate titanate nanowire in the porous dielectric material, and when the doping proportion of the lead zirconate titanate nanowire reaches 15%, the pressure responsiveness is increased to a small extent, namely the sensitivity of the flexible capacitive pressure sensor cannot be greatly improved; the flexible capacitive pressure sensors of examples 1-4 showed an ultra-wide pressure response interval (0-2750 kPa); the porous dielectric material of the flexible capacitive pressure sensor of the comparative example is not doped with lead zirconate titanate nanowires and has no pressure responsiveness.
2) The flexible capacitive pressure sensor of example 3 was used for pulse testing of different populations, and the test result graph is shown in fig. 6.
As can be seen from fig. 6: the flexible capacitive pressure sensor of embodiment 3 has a good differentiating effect on pulse signals of different people.
In addition, the flexible capacitive pressure sensors of examples 1, 2 and 4 were found to have a good discrimination effect on pulse signals of different populations by performing the same tests.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (10)
1. A porous dielectric material, comprising a polymer matrix and ceramic nanowires; the ceramic nanowires are distributed in the polymer matrix and on the surface of the polymer matrix; a plurality of holes are distributed in the porous dielectric material and on the surface of the porous dielectric material.
2. The porous dielectric material of claim 1, wherein: the porosity of the porous dielectric material is 50-80%.
3. A porous dielectric material according to claim 1 or 2, wherein: the polymer matrix is composed of at least one of polydimethylsiloxane, polyurethane, polyimide and polyvinyl alcohol.
4. A porous dielectric material according to claim 1 or 2, characterized in that: the ceramic nanowire is at least one of lead zirconate titanate nanowire, zirconium oxide nanowire, barium titanate nanowire, zinc oxide nanowire, aluminum oxide nanowire and silicon carbide nanowire.
5. A porous dielectric material according to claim 1 or 2, wherein: the length of the ceramic nanowire is 5-50 μm, and the diameter of the ceramic nanowire is 10-50 nm.
6. A porous dielectric material according to claim 1 or 2, characterized in that: the addition amount of the ceramic nanowire is 3% -20% of the mass of the polymer matrix.
7. A method of preparing a porous dielectric material according to any of claims 1 to 6 comprising the steps of: and uniformly mixing the polymer matrix material, the ceramic nanowires and the polymer microspheres to prepare a film, and dissolving to remove the polymer microspheres in the film to obtain the porous dielectric material.
8. The method of claim 7, wherein: the polymer microspheres are at least one of polystyrene microspheres, silicon dioxide microspheres, melamine resin microspheres, polyvinyl toluene microspheres and polymethacrylate microspheres.
9. The production method according to claim 7 or 8, characterized in that: the diameter of the polymer microsphere is 1-10 μm.
10. A flexible capacitive pressure sensor comprising the porous dielectric material of any one of claims 1 to 6.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170075467A1 (en) * | 2015-09-11 | 2017-03-16 | Korea Institute Of Science And Technology | Capacitive force sensor and method for preparing the same |
| CN109785995A (en) * | 2018-12-07 | 2019-05-21 | 深圳大学 | A kind of porous, electrically conductive slurry and its preparation method and application being used to prepare flexible piezoresistive transducer |
| CN110455443A (en) * | 2019-08-23 | 2019-11-15 | 北京航空航天大学 | A kind of flexible capacitive sensor and preparation method thereof using the preparation of silver nanowires flexible electrode |
| CN113218543A (en) * | 2021-05-07 | 2021-08-06 | 中国科学院苏州纳米技术与纳米仿生研究所 | Flexible pressure sensor, dielectric layer thereof and preparation method of dielectric layer |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170075467A1 (en) * | 2015-09-11 | 2017-03-16 | Korea Institute Of Science And Technology | Capacitive force sensor and method for preparing the same |
| CN109785995A (en) * | 2018-12-07 | 2019-05-21 | 深圳大学 | A kind of porous, electrically conductive slurry and its preparation method and application being used to prepare flexible piezoresistive transducer |
| CN110455443A (en) * | 2019-08-23 | 2019-11-15 | 北京航空航天大学 | A kind of flexible capacitive sensor and preparation method thereof using the preparation of silver nanowires flexible electrode |
| CN113218543A (en) * | 2021-05-07 | 2021-08-06 | 中国科学院苏州纳米技术与纳米仿生研究所 | Flexible pressure sensor, dielectric layer thereof and preparation method of dielectric layer |
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