Pressure-humidity composite array type flexible sensor based on 3D printing

Abstract

The utility model relates to an array type flexible pressure-humidity composite sensor based on 3D printing, which belongs to the technical field of sensors and comprises an upper insulating protective film, a lower insulating protective film and an insulating flexible middle layer arranged between the upper insulating protective film and the lower insulating protective film. A plurality of pressure sensing elements and humidity sensing elements are embedded in the holes, so that pressure and humidity information can be measured at the same time; the sensing elements are all independent leads, so that signal interference among sensor arrays is reduced; the upper electrode of the humidity sensing element is an interdigital electrode, so that the sensitive layer is ensured to be in full contact with the environment; and the embedded design can effectively reduce the interlayer falling risk and prolong the service life of the sensor. The sensor is integrally prepared through the 3D printing technology, has the advantages of being simple in processing technology, rapid in forming and the like, can solve the problems that in the preparation process of a current array type flexible pressure-humidity composite sensor, the technology is complex, consumed time is long and the like, and can be suitable for simultaneous monitoring of a pressure signal and a humidity signal in a complex environment.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, and in particular, to a pressure-humidity composite array flexible sensor based on 3D printing. Background Art

[0002] With the development of technology, as one of the core technologies of intelligent sensing terminals, flexible wearable sensors have attracted more and more attention from researchers due to their broad and interesting application prospects.

[0003] However, in the prior art, most wearable sensors such as pressure sensors, humidity sensors, temperature sensors, etc. have a single function and can only measure a single parameter. To monitor different key parameters, multiple different types of sensors need to be worn, resulting in problems such as too many wearable devices and a decrease in human comfort, and it is difficult to meet the integrated and multi-functional requirements in actual monitoring scenarios. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is that the detection function of wearable sensors is single and multiple sensors need to be worn for multiple detections, resulting in inconvenient wearing. To overcome the above defects of the prior art, the utility model provides a pressure-humidity composite array flexible sensor based on 3D printing.

[0005] The utility model provides a pressure-humidity composite array flexible sensor based on 3D printing, which includes an insulating flexible intermediate layer and insulating protective films respectively arranged on the front and back sides of the insulating flexible intermediate layer. A plurality of piezoelectric elements for detecting pressure and humidity detection elements for detecting humidity are arranged in the insulating flexible intermediate layer. The insulating protective film on one side close to the detection end of the humidity detection element is hollowed out. The electrodes of each piezoelectric element and humidity detection element are respectively led out to one side edge around the insulating flexible intermediate layer through wires.

[0006] Compared with the prior art, a pressure-humidity composite array flexible sensor of the present application has the following advantages: through the insulating flexible intermediate layer, the piezoelectric elements and humidity detection elements can be accommodated and fixed at the same time, and the piezoelectric elements and humidity detection elements jointly detect to achieve multiple detections; at the same time, the insulating flexible intermediate layer is used as a fixing part, which is convenient to bend, so that it is also convenient to wear during the measurement process. With multiple piezoelectric elements and humidity detection elements, and each piezoelectric element and humidity detection element is independently wired, it is convenient for wiring to avoid crosstalk. By obtaining multiple data through independent wiring, it is possible to better detect sliding and bending data, and the detection is more comprehensive.

[0007] In a possible implementation, a plurality of first accommodation through-holes for accommodating piezoelectric elements and second accommodation through-holes for accommodating humidity detection elements are provided in a hollowed-out manner within the insulating flexible intermediate layer. Each piezoelectric element is fixedly embedded in a first accommodation through-hole, and each humidity detection element is fixedly embedded in a second accommodation through-hole.

[0008] Compared with the prior art, the hollowed-out embedded design makes the fixation of each piezoelectric element and humidity detection element more firm.

[0009] In a possible implementation, each piezoelectric element includes a piezoelectric unit for detecting pressure, a first electrode and a second electrode respectively disposed on the front and rear sides of the piezoelectric unit. The first electrode and the second electrode are both electrically connected to the piezoelectric unit, and the first electrode and the second electrode are respectively led out from the front and rear sides of the insulating flexible intermediate layer to one side edge of the periphery of the insulating flexible intermediate layer through a first wire.

[0010] Compared with the prior art, the piezoelectric element has electrodes disposed on both sides, and in combination with an external insulating protective film, the connection between the electrode and the piezoelectric unit is closer, and it can protect the piezoelectric unit, and it is also convenient to lead out the wires from both sides to prevent difficulties in leading out too many wires.

[0011] In a possible implementation, each humidity detection unit includes a humidity detection unit for detecting humidity, a third electrode and a fourth electrode respectively disposed on the front and rear sides of the humidity detection unit. The third electrode and the fourth electrode are both electrically connected to the humidity detection unit. The front side of the humidity detection unit is the detection end. The third electrode is an interdigital electrode, and the third electrode and the fourth electrode are respectively led out from the front and rear sides of the insulating flexible intermediate layer to one side edge of the periphery of the insulating flexible intermediate layer through a second wire.

[0012] Compared with the prior art, the humidity detection element has electrodes disposed on both sides, and in combination with an external insulating protective film, the connection between the electrode and the humidity detection unit is closer, and it can protect the humidity detection unit, and it is also convenient to lead out the wires from both sides to prevent difficulties in leading out too many wires.

[0013] In a possible implementation, the piezoelectric elements and humidity detection elements near the left side of the insulating flexible intermediate layer are respectively led out to the left edge of the insulating flexible intermediate layer through the first wire and the second wire; the piezoelectric elements and humidity detection elements near the right side of the insulating flexible intermediate layer are respectively led out to the right edge of the insulating flexible intermediate layer through the first wire and the second wire; the piezoelectric elements and humidity detection elements near the upper side of the insulating flexible intermediate layer are respectively led out to the upper edge of the insulating flexible intermediate layer through the first wire and the second wire; the piezoelectric elements and humidity detection elements near the lower side of the insulating flexible intermediate layer are respectively led out to the lower edge of the insulating flexible intermediate layer through the first wire and the second wire.

[0014] Compared with the prior art, the wires of each piezoelectric element and humidity detection element are led out and distributed around the insulating flexible intermediate layer according to the principle of proximity, preventing a large number of wires due to unilateral wiring, which is not convenient for connection.

[0015] In a possible implementation, M*N piezoelectric elements distributed in a matrix and (M - 1)*(N - 1) humidity detection elements distributed in a matrix are uniformly arranged in the insulating flexible intermediate layer, and each humidity detection element is arranged at the center of the virtual rectangle surrounded by every four piezoelectric elements; where M and N are both positive integers greater than or equal to 2.

[0016] Compared with the prior art, the humidity detection elements are arranged between the piezoelectric elements, making full use of the space and enabling more comprehensive detection of pressure and humidity in all directions.

[0017] In a possible implementation, the insulating flexible intermediate layer is insulating silica gel.

[0018] In a possible implementation, the insulating protective film is a PI film.

[0019] In a possible implementation, the cross-section of the piezoelectric element is circular, and the cross-section of the humidity detection element is square.

[0020] Compared with the prior art, the outer shapes of the two different elements are set to different structures for easy distinction. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of a pressure-humidity composite array flexible sensor based on 3D printing according to the present invention;

[0022] Figure 2 It is a schematic diagram of the structure of the piezoelectric element in a pressure-humidity composite array flexible sensor based on 3D printing according to the present invention;

[0023] Figure 3Schematic diagram of the humidity detection element structure in a pressure-humidity composite array flexible sensor based on 3D printing according to the present utility model;

[0024] Figure 4 Distribution diagram of the wires of a pressure-humidity composite array flexible sensor based on 3D printing according to the present utility model.

[0025] Explanation of the reference numerals:

[0026] 1 - Insulating flexible intermediate layer; 11 - First accommodation through hole; 12 - Second accommodation through hole;

[0027] 2 - Piezoelectric element; 21 - Piezoelectric unit; 22 - First electrode; 23 - Second electrode;

[0028] 3 - Humidity detection element; 31 - Humidity detection unit; 32 - Third electrode; 33 - Fourth electrode. Specific embodiments

[0029] First of all, those skilled in the art should understand that these embodiments are only used to explain the technical principles of the embodiments of the present application and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios.

[0030] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0031] In the embodiments of the present application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on the upper side" of the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "on the lower side" of the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0032] The following further elaborates on the present application in conjunction with the accompanying drawings and specific embodiments.

[0033] See Figures 1 to 4As shown in the figure, an embodiment of the present application discloses a pressure-humidity composite array flexible sensor based on 3D printing, which includes an insulating flexible intermediate layer 1 and insulating protective films respectively arranged on the front and back sides of the insulating flexible intermediate layer 1.

[0034] A plurality of piezoelectric elements 2 for detecting pressure and humidity detection elements 3 for detecting humidity are arranged in an array in the insulating flexible intermediate layer 1. The insulating protective film on the side close to the detection end of the humidity detection element 3 is hollowed out. The electrodes of each piezoelectric element 2 and humidity detection element 3 are respectively led out to one side edge of the periphery of the insulating flexible intermediate layer 1 through wires.

[0035] The plurality of piezoelectric elements 2 and humidity detection elements 3 are fixed through the insulating flexible intermediate layer 1, and then encapsulated through the insulating protective film, so that it can detect pressure and humidity simultaneously in one sensor package, and the detection function is more perfect; and each piezoelectric element 2 and humidity detection element 3 are respectively led out through wires, which is convenient for wire leading.

[0036] In this embodiment, the insulating flexible intermediate layer 1 is insulating silica gel, and the insulating protective film is a pi film. Among them, the insulating silica gel can be made by 3D printing technology.

[0037] Each piezoelectric element 2 and humidity detection element 3 are embedded in the insulating silica gel to make up for the defect that the 3D printed layered structure is easy to fall off under the action of large stress.

[0038] In the encapsulation of the entire sensor, the pi film is used, which has the advantages of good heat resistance, strong mechanical properties, and good dielectric properties.

[0039] In this embodiment, a plurality of first accommodation through holes 11 for accommodating the piezoelectric elements 2 and second accommodation through holes 12 for accommodating the humidity detection elements 3 are hollowed out in the insulating flexible intermediate layer 1. Each piezoelectric element 2 is embedded and fixed in a first accommodation through hole 11, and each humidity detection element 3 is embedded and fixed in a second accommodation through hole 12.

[0040] The hollowed-out embedded design makes each piezoelectric element 2 and humidity detection element 3 fixed more firmly.

[0041] In this embodiment, each piezoelectric element 2 includes a piezoelectric unit 21 for detecting pressure, a first electrode 22 and a second electrode 23 respectively arranged on the front and back sides of the piezoelectric unit 21. The first electrode 22 and the second electrode 23 are both electrically connected to the piezoelectric unit 21. The first electrode 22 and the second electrode 23 are respectively led out to one side edge of the periphery of the insulating flexible intermediate layer 1 from the front and back sides of the insulating flexible intermediate layer 1 through a first wire.

[0042] The piezoelectric element 2 has electrodes disposed on both sides, and is combined with an external insulating protective film, so that the connection between the electrodes and the piezoelectric unit 21 is tighter, and it can protect the piezoelectric unit 21 and is also convenient for wire extraction.

[0043] In this embodiment, the piezoelectric unit 21 is made of a mixed solution of PDMS with strong flexibility and perovskite by 3D printing technology. Specifically, 15 wt% of BCST filler is added to the polymer PDMS, so that the piezoelectric performance of the composite abrasive is greatly improved.

[0044] As a functional material, PDMS has the advantages of ultra-flexibility, chemical inertness, and high thermal stability. By using lead-free piezoelectric fillers, while ensuring the original flexibility of PDMS, the piezoelectric performance is improved.

[0045] In this embodiment, for both the first electrode 22 and the second electrode 23, 3D printing technology is used to print silver paste as the electrode.

[0046] Traditional manufacturing processes are costly, difficult to mass-produce, and difficult to form. As a popular additive manufacturing technology in recent years, 3D printing technology well compensates for these defects. It has stable electric potential, good reproducibility, a firm electrode structure, small temperature hysteresis, and can be used at high temperatures. Moreover, compared with traditional manufacturing methods, when printed by 3D printing technology, the electrode shape is more variable, the printing position and size are more accurate, and the material loss is less.

[0047] The piezoelectric unit 21, the first electrode 22, and the second electrode 23 are all made by 3D printing technology. In this embodiment, the piezoelectric unit 21, the first electrode 22, and the second electrode 23 are three cylinders with equal bottom surfaces, that is, the cross-section of the piezoelectric element 2 is circular.

[0048] Each humidity detection element 3 includes a humidity detection unit 31 for detecting humidity, a third electrode 32 and a fourth electrode 33 respectively disposed on the front and rear sides of the humidity detection unit 31. The third electrode 32 and the fourth electrode 33 are both electrically connected to the humidity detection unit 31. The front side of the humidity detection unit 31 is the detection end. The third electrode 32 is an interdigital electrode. The third electrode 32 and the fourth electrode 33 are respectively led out from the front and rear sides of the insulating flexible intermediate layer 1 to one side edge around the insulating flexible intermediate layer 1 through a second wire.

[0049] Similar to the piezoelectric element 2, the humidity detection element 3 can also be set in a cylindrical shape, but for the convenience of distinction, in this embodiment, the humidity detection element 3 is set in a cuboid shape, that is, the cross-section of the humidity detection element 3 is square.

[0050] Among them, the piezoelectric element 2 and the humidity detection element 3 close to the left side of the insulating flexible intermediate layer 1 are respectively led out to the left side edge of the insulating flexible intermediate layer 1 through a first wire and a second wire;

[0051] The piezoelectric element 2 and the humidity detection element 3 near the right side of the insulating flexible intermediate layer 1 are respectively led out to the right side edge of the insulating flexible intermediate layer 1 through the first wire and the second wire;

[0052] The piezoelectric element 2 and the humidity detection element 3 near the upper side of the insulating flexible intermediate layer 1 are respectively led out to the upper side edge of the insulating flexible intermediate layer 1 through the first wire and the second wire;

[0053] The piezoelectric element 2 and the humidity detection element 3 near the lower side of the insulating flexible intermediate layer 1 are respectively led out to the lower side edge of the insulating flexible intermediate layer 1 through the first wire and the second wire.

[0054] Specifically, in this embodiment, the piezoelectric element 2 and the humidity detection element 3 near the leftmost side of the insulating flexible intermediate layer 1 are led out to the left side edge of the insulating flexible intermediate layer 1 through the first wire and the second wire, and the piezoelectric element 2 and the humidity detection element 3 near the rightmost side of the insulating flexible intermediate layer 1 are led out to the right side edge of the insulating flexible intermediate layer 1 through the first wire and the second wire.

[0055] The remaining half of the piezoelectric elements 2 and humidity detection elements 3 are led out to the upper side edge of the insulating flexible intermediate layer 1 through the first wire and the second wire, and the remaining other half of the piezoelectric elements 2 and humidity detection elements 3 are led out to the lower side edge of the insulating flexible intermediate layer 1 through the first wire and the second wire.

[0056] By setting a certain wiring rule, it is convenient to lead out the wires and avoid the wiring difficulty caused by concentrated wiring.

[0057] Of course, in actual design, other wiring rules can also be adopted. For example: the wires are evenly divided into four parts and led out from the four directions of up, down, left, and right of the insulating flexible intermediate layer 1; or, they are evenly divided into two parts and led out from the left and right directions of the insulating flexible intermediate layer 1.

[0058] In this embodiment, M*N piezoelectric elements 2 distributed in a matrix form and (M - 1)*(N - 1) humidity detection elements 3 distributed in a matrix form are evenly arranged in the insulating flexible intermediate layer 1, and each humidity detection element 3 is arranged at the center of the virtual rectangle surrounded by every four piezoelectric elements 2; where M and N are both positive integers greater than or equal to 2.

[0059] In the description of the embodiments of the present application, it should be noted that in the description of the present application, the terms "inside", "outside", etc. indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present application.

[0060] In the description of the present application, the descriptions referring to terms such as "one embodiment", "some embodiments", "in this embodiment", "specific example", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0061] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A 3D printed pressure-humidity composite array flexible sensor, characterized in that: The invention comprises an insulating flexible middle layer (1) and insulating protective films respectively arranged on the front and rear sides of the insulating flexible middle layer (1); a plurality of piezoelectric elements (2) for detecting pressure and humidity detection elements (3) for detecting humidity are arranged in the insulating flexible middle layer (1); the insulating protective film on the side close to the detection end of the humidity detection element (3) is hollow; the electrodes of each of the piezoelectric element (2) and humidity detection element (3) are respectively led out to the edge of one side around the insulating flexible middle layer (1) through wires.

2. The 3D-printed pressure-humidity composite array flexible sensor according to claim 1, characterized in that: The insulating flexible intermediate layer (1) is hollowed out to form a plurality of first accommodating through holes (11) for accommodating piezoelectric elements (2) and second accommodating through holes (12) for accommodating humidity detection elements (3); each of the piezoelectric elements (2) is embedded and fixed in a first accommodating through hole (11), and each of the humidity detection elements (3) is embedded and fixed in a second accommodating through hole (12).

3. The 3D printing-based pressure-humidity composite array flexible sensor according to claim 1, characterized in that: Each of the piezoelectric elements (2) comprises a piezoelectric unit (21) for detecting pressure, a first electrode (22) and a second electrode (23) respectively arranged on the front and rear sides of the piezoelectric unit (21), the first electrode (22) and the second electrode (23) are both electrically connected to the piezoelectric unit (21), and the first electrode (22) and the second electrode (23) are respectively led out from the front and rear sides of the insulating flexible middle layer (1) to the edge of one side around the insulating flexible middle layer (1) through a first wire.

4. The 3D printing-based pressure-humidity composite array flexible sensor according to claim 1, characterized in that: Each of the humidity detection elements (3) comprises a humidity detection unit (31) for detecting humidity, a third electrode (32) and a fourth electrode (33) respectively arranged on the front and rear sides of the humidity detection unit (31), the third electrode (32) and the fourth electrode (33) are both electrically connected to the humidity detection unit (31), the front side of the humidity detection unit (31) is a detection end, the third electrode (32) is an interdigitated electrode, and the third electrode (32) and the fourth electrode (33) are respectively led out from the front and rear sides of the insulating flexible intermediate layer (1) to the edge of one side around the insulating flexible intermediate layer (1) through a second wire.

5. The 3D printing-based pressure-humidity composite array flexible sensor according to claim 1, characterized in that: The piezoelectric element (2) and the humidity detection element (3) close to the left side of the insulating flexible middle layer (1) are respectively led out to the left edge of the insulating flexible middle layer (1) through a first wire and a second wire; The piezoelectric element (2) and the humidity detection element (3) close to the right side of the insulating flexible middle layer (1) are respectively led out to the right side edge of the insulating flexible middle layer (1) through a first wire and a second wire; The piezoelectric element (2) and the humidity detection element (3) close to the upper side of the insulating flexible middle layer (1) are respectively led out to the upper side edge of the insulating flexible middle layer (1) through a first wire and a second wire; The piezoelectric element (2) and the humidity detection element (3) close to the lower side of the insulating flexible intermediate layer (1) are respectively led out to the lower edge of the insulating flexible intermediate layer (1) through a first wire and a second wire.

6. The 3D printing-based pressure-humidity composite array flexible sensor according to claim 1, characterized in that: The insulating flexible intermediate layer (1) is evenly provided with M*N matrix-distributed piezoelectric elements (2) and (M-1)*(N-1) matrix-distributed humidity detection elements (3), each of the humidity detection elements (3) being arranged at the center of a virtual rectangle surrounded by every four piezoelectric elements (2); wherein M and N are both positive integers greater than or equal to 2.

7. The 3D printing-based pressure-humidity composite array flexible sensor according to claim 1, characterized in that: The insulating flexible intermediate layer (1) is insulating silica gel.

8. The 3D printing-based pressure-humidity composite array flexible sensor according to claim 1, characterized in that: The insulating protective film is a pi film.

9. The 3D printing-based pressure-humidity composite array flexible sensor according to claim 1, characterized in that: The cross section of the piezoelectric element (2) is circular, and the cross section of the humidity detection element (3) is square.

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