A hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil

Abstract

The present invention discloses a hollow shell PDMS flexible pressure sensing device with an embedded planar inductive coil, comprising: a flexible backing, a hollow shell porous PDMS support body, and a mounting frame; the hollow shell porous PDMS support body is fixed to the upper limit of the flexible backing; a PI film that matches the flexible backing is adhered to the top of the hollow shell porous PDMS support body; and the outer sides of the flexible backing and the PI film are wrapped with radiation-proof cloth. The present invention realizes the operation of rapid and automatic resetting of the support body and continuous pressure detection. When pressure gradually acts on the top of the porous PDMS support body, the entire sponge body is gradually compressed, so that the relative distance between the coils inside it gradually decreases, and the inductance value of the entire circuit increases accordingly. When the external pressure is gradually removed, the entire hollow shell porous PDMS support body gradually returns to its original shape under the action of elasticity. The present invention can achieve an ideal height, improve flexibility, and have good anti-interference ability, making the detection process more accurate and practical.

Description

Technical Field

[0001] The present invention relates to the field of pressure sensing technology, and in particular to a hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil. Background Art

[0002] As the core part of flexible electronic devices, flexible sensors have the advantages of strong elasticity, high softness, and easy adhesion to the surface of machines. They have broad application prospects and huge application potential in ship pressure detectors, human health monitoring bracelets, artificial intelligence equipment, biomedical devices, microfluidic equipment, energy harvesting equipment and flexible electronic skin.

[0003] At present, the main problems faced by flexible sensors are high production costs, complicated production processes, small working range, low sensitivity, poor anti-interference ability, etc. In order to overcome the above shortcomings, many new types of flexible pressure sensors are constantly being proposed and improved. At present, the flexible pressure sensors that have been developed can be roughly divided into four categories according to their detection principles: piezoresistive, piezoelectric, capacitive and triboelectric. Among them, the capacitive flexible pressure sensor is the most studied, which uses the change of its own capacitance as the basic principle to detect and indicate changes in external pressure. It has relatively superior sensitivity, especially for the detection of small pressure signals. However, this type of sensor is very susceptible to interference from the external environment and the influence of its own vibration, which greatly reduces the possibility of putting capacitive sensors into practical application.

[0004] In order to solve this problem, the present invention proposes an inductive flexible pressure sensor, which uses the inductance change between two micro-planar inductor coils as the key point to detect pressure changes. It has extremely strong anti-interference ability, and the manufacturing process is very simple and the manufacturing cost is relatively low. It has far-reaching significance for the development and research of flexible pressure sensors. Summary of the Invention

[0005] The purpose of the present invention is to solve the shortcomings existing in the prior art, such as: the existing capacitive flexible pressure sensor has poor anti-interference ability, and the elastic element needs to be reset in time to ensure that the data during the next detection is more accurate; the pressure sensing device is installed in the outside for a long time, which will corrode the surface of the pressure sensing device and cause oxidation on the surface of the pressure sensing device. During pressure detection, the surface is prone to cracking, affecting the use of the pressure sensing device and reducing its service life; there are wires outside the pressure sensing device, and during the installation and use process, the wires are prone to breakage and falling off after being pulled, making the pressure sensing device more inconvenient to use and reducing its practicality.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil comprises a flexible substrate, a hollow shell porous PDMS support, and a mounting bracket. The hollow shell porous PDMS support is fixed to the upper limit of the flexible substrate. A PI film that matches the flexible substrate is adhered to the top of the hollow shell porous PDMS support. The flexible substrate and the PI film are wrapped with radiation-proof cloth. A first inductor coil and a second inductor coil are fixedly mounted on the inner wall of the hollow shell porous PDMS support, respectively. The outer sides of the first inductor coil and the second inductor coil are electrically connected to a first wire and a second wire extending from the hollow shell porous PDMS support, respectively. The mounting bracket is fixedly mounted on the outer side of the flexible substrate.

[0008] The outer side of the mounting frame is fixedly connected to a fixing rod, and the top and bottom of the fixing rod are movably mounted with a first clamping block and a second clamping block, one side of the first clamping block and the second clamping block is fixedly mounted with a fixing block, the inner side of the fixing block is spirally mounted with an extrusion block through a screw rod, and the outer side of the fixing block is fixedly mounted with a fixing frame that cooperates with the screw rod.

[0009] Preferably, the flexible base liner and the hollow shell-shaped porous PDMS support body are fixed by a mounting groove, and the flexible base liner is flush with the top of the hollow shell-shaped porous PDMS support body.

[0010] Preferably, the PI film is yellow and transparent, and is made of insulating material.

[0011] Preferably, the radiation-proof cloth is made of silver fiber fabric, and the surface of the radiation-proof cloth is covered with a protective layer.

[0012] Preferably, the radiation-proof cloth is made of silver fiber fabric, and the surface of the radiation-proof cloth is covered with a protective layer.

[0013] Preferably, the outer side of the protective layer is wrapped with a wear-resistant layer, and the wear-resistant layer is made of polyethylene plastic.

[0014] Preferably, the hollow shell-shaped porous PDMS support body and the flexible base are slidably installed via a sliding block, and the inner wall of the flexible base is provided with a sliding groove that cooperates with the sliding block.

[0015] Preferably, the hollow shell-shaped porous PDMS support body is adhered and fixed to the first inductor coil and the second inductor coil by adhesive tape, and the first inductor coil and the second inductor coil are installed in parallel and opposite to each other.

[0016] Preferably, mounting seats are welded to the top and bottom of the fixing rod, and the mounting seats are movably mounted to the first clamping block and the second clamping block via a movable shaft.

[0017] Preferably, the first clamping block and the second clamping block are fixed by a fixing knob, and a docking rod cooperating with the fixing knob is fixedly installed on the inner side of the second clamping block.

[0018] Preferably, a protective pad is adhered to the inner side of the extrusion block, and a rotating disk is welded to the outer side of the screw rod.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention is applied in detection and has strong anti-interference ability. This inductive detection scheme is also highly resistant to electromagnetic interference, and its output signal will not fluctuate significantly due to the presence of surrounding electromagnetic signals. In contrast, when there is external electromagnetic interference, the output signal of the capacitive sensor also produces continuous and large fluctuations. Therefore, the capacitive sensor is not resistant to external interference. Electromagnetic interference and biological interference are the most common types of interference in life. If the sensor is put into commercial use, such interference is inevitable. Therefore, this shortcoming of the capacitive sensor greatly reduces the possibility of its application in real life. This further highlights the research value and significance of studying inductive pressure sensors with strong anti-interference ability.

[0021] The present invention realizes a fast automatic reset operation. By providing a hollow shell-shaped porous PDMS support body, a PI film, a second inductance coil and a first inductance coil, when the sensor is not subjected to external pressure, the entire hollow shell-shaped porous PDMS support body is supported by the flexible porous walls on all sides and the entire sponge is in an upright state. When pressure gradually acts on the top of the porous PDMS support body, the flexible porous walls on all sides will gradually undergo outward flexible bending and expansion, and the entire hollow shell-shaped porous PDMS support body will gradually be compressed, causing the planar inductance coil fixed on its top layer to gradually approach the planar inductance coil at its bottom, thereby reducing the distance between the first inductance coil and the second inductance coil, and the inductance value of the entire circuit continues to rise. When the external pressure is gradually removed, the entire hollow shell-shaped porous PDMS support body gradually returns to its original shape under the action of elasticity, so that the relative distance between the coils inside it gradually decreases, and the inductance value of the entire circuit decreases accordingly, making the detection process more convenient and increasing practicality.

[0022] The present invention is provided with anti-radiation cloth, and the protective layer and the wear-resistant layer cooperate with each other, and utilizes silver fiber fabric, which can effectively play a role in radiation protection. The silver fiber fabric is a blend of metal fiber and cloth fiber to form a metal mesh, which can conveniently play a role in radiation protection. At the same time, it is made of polyethylene plastic and can be conveniently wear-resistant, so that the surface can be conveniently wear-resistant during the detection and extrusion process, making it more efficient during use and increasing the service life.

[0023] The present invention is provided with a first clamping block, a fixing block, a second clamping block and an extruding block that cooperate with each other, and can synchronously drive the screw rod to rotate by rotating the rotating disk, so that the screw rod can move toward the inner side of the fixing block along the fixing frame, and can conveniently bring the extruding blocks close to each other, clamp and fix the first wire and the second wire, and can protect the first wire and the second wire through the protective pad, effectively preventing the first wire and the second wire from being damaged by excessive clamping force, and preventing the external pulling force from being too strong, which may cause the wires to fall off and break, thereby increasing practicality and convenience. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the three-dimensional structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the partial structure of the hollow shell porous PDMS support of the present invention;

[0026] Figure 3 This is a schematic diagram of the front internal structure of the hollow shell-shaped porous PDMS support of the present invention;

[0027] Figure 4 It is a schematic diagram of the local structure of the fixing sleeve of the present invention;

[0028] Figure 5 It is a schematic diagram of the local structure of the fixing rod of the present invention;

[0029] Figure 6 It is a schematic diagram of the local structure of the extrusion block of the present invention.

[0030] In the figure: 1-flexible backing; 101-PI film; 102-sliding groove; 103-radiation protection cloth; 104-protective layer; 105-wear-resistant layer; 106-mounting groove; 2-hollow shell-shaped porous PDMS support; 201-adhesive tape; 202-sliding block; 203-first inductor coil; 204-second inductor coil; 205-first wire; 206-second wire; 3-mounting frame; 301-fixing rod; 302-mounting seat; 303-movable shaft; 4-first clamping block; 401-second clamping block; 402-docking rod; 403-fixing knob; 404-fixing block; 405-extrusion block; 406-protective pad; 407-screw; 408-fixing frame; 409-rotating disk. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," "the other end," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "connected," etc., should be understood in a broad sense. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection or an electrical connection; it may refer to a direct connection or an indirect connection through an intermediate medium; it may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0034] Example 1

[0035] See also Figure 1-6The present invention proposes a hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil, comprising a flexible substrate 1, a hollow shell porous PDMS support 2 and a mounting frame 3. The top of the flexible substrate 1 is fixed with the hollow shell porous PDMS support 2 by a mounting groove 106. The top of the hollow shell porous PDMS support 2 is docked with a PI film 101 that matches the flexible substrate 1. The hollow shell porous PDMS support 2 is fixed to the first inductor coil 203 and the second inductor coil 204 by an adhesive tape 201. The adhesive tape 201 can be used to conveniently install the first inductor coil 203 and the second inductor coil 204 inside the hollow shell porous PDMS support 2. The porous structure inside the S support 2 allows the PI film 101 to be easily deformed and squeezed against the top of the hollow shell porous PDMS support 2. The PI film 101 can be used to effectively protect the sensor. The PI film 101 has good insulation properties and is also helpful in isolating the sensor from external air interference, making it more convenient to use. It can make the functional elements in the inductive sensor and bring the two parallel opposing micro-planar inductor coils infinitely close, greatly optimizing the structure of the sensor. The porous hollow shell structure is more conducive to improving the flexibility and elasticity of the entire flexible PDMS support, further improving the sensitivity of the sensor. The hollow shell porous PDMS support can be easily mounted using the mounting groove 106. The body 2 is installed inside the flexible base liner 1 and the PI film 101, and the hollow shell-shaped porous PDMS support body 2 can be conveniently limited and fixed, which makes the hollow shell-shaped porous PDMS support body 2 more convenient to install and increases practicality. The outside of the flexible base liner 1 and the PI film 101 is wrapped with an anti-radiation cloth 103, and the material of the anti-radiation cloth 103 is made of silver fiber fabric, and the surface of the anti-radiation cloth 103 is provided with a protective layer 104, and the outside of the protective layer 104 is covered with a wear-resistant layer 105, and the material of the wear-resistant layer 105 is made of polyethylene plastic. The anti-radiation cloth 103 is made of silver fiber fabric, which can effectively prevent radiation. The silver fiber fabric is a blend of metal fiber and cloth fiber to form a metal mesh, which can conveniently play a role in radiation protection. The hollow shell porous PDMS support 2 is slidably installed with the flexible substrate 1 and the PI film 101 through the sliding block 202. The inner wall of the PI film 101 and the flexible substrate 1 is provided with a sliding groove 102 that cooperates with the sliding block 202. The sliding block 202 slides along the inside of the sliding groove 102, which can facilitate the first inductance coil 203 and the second inductance coil 204 to be in a parallel state during the deformation process, making the measurement process more accurate, increasing practicality, and improving the accuracy of pressure measurement.A first inductor coil 203 and a second inductor coil 204 are attached to the inner wall of the hollow shell-shaped porous PDMS support 2 via adhesive tape 201. The first inductor coil 203 and the second inductor coil 204 are mounted parallel to each other. The adhesive tape 201 facilitates gluing the first and second inductor coils 203 and 204 to the inner wall of the hollow shell-shaped porous PDMS support 2, preventing them from falling off and increasing stability. The outer sides of the first and second inductor coils 203 and 204 are electrically connected to a first wire 205 and a second wire 206 extending from the hollow shell-shaped porous PDMS support 2. The proximity of the first and second inductor coils 203 and 204 causes a change in inductance, and pressure is detected based on this change, increasing practicality.

[0036] Example 2

[0037] See also Figure 1-6The present invention proposes a hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil. Compared with the first embodiment, this embodiment further includes: a mounting bracket 3 is fixedly installed on the outside of the flexible substrate 1 and the PI film 101, and a fixing rod 301 is fixedly connected to the outside of the mounting bracket 3. The fixing rod 301 can be conveniently installed through the mounting bracket 3. A mounting seat 302 is welded on the top of the fixing rod 301. The mounting seat 302 is movably installed with the first clamping block 4 and the second clamping block 401 through a movable shaft 303, which makes it more convenient to fix the first wire 205 and the second wire 206, thereby increasing convenience. At the same time, the mounting bracket 3 is used to fix the first wire 205 and the second wire 206. 02 can connect the first clamping block 4 and the second clamping block 401, and the first clamping block 4 and the second clamping block 401 can be easily flipped by using the movable shaft 303, which makes it more convenient to clamp and fix them, and increases practicality. The first clamping block 4 and the second clamping block 401 are fixed by a fixing knob 403, and a docking rod 402 that cooperates with the fixing knob 403 is fixedly installed on the inner side of the second clamping block 401. The first clamping block 4 and the second clamping block 401 can be easily flipped by using the movable shaft 303, and the fixing knob 403 and the docking rod 402 are used to limit and fix them, so that when the first wire 2 is clamped, the first wire 2 is clamped. 05 and the second wire 206 are clamped more conveniently, so that the first wire 205 and the second wire 206 can be easily fixed when they are pulled, to prevent excessive external pulling force from causing the wires to fall off and break, thereby increasing practicality. A fixed block 404 is fixedly installed on one side of the first clamping block 4 and the second clamping block 401, and a fixed frame 408 that cooperates with the screw rod 407 is fixedly installed on the outside of the fixed block 404. A rotating disk 409 is welded on the outside of the screw rod 407. By rotating the rotating disk 409, the screw rod 407 can be synchronously driven to rotate, so that the screw rod 407 can move along the fixed frame 408 to the inside of the fixed block 404. , it is possible to easily bring the extrusion blocks 405 close to each other, clamp and fix the first wire 205 and the second wire 206, making the clamping process more stable, the operation convenient and quick, and increasing practicality. The inner side of the fixing block 404 is spirally installed with the extrusion block 405 through the screw rod 407, and the inner side of the extrusion block 405 is adhered with a protective pad 406. The extrusion block 405 can be used to conveniently clamp, and at the same time, the protective pad 406 can be used to protect the first wire 205 and the second wire 206, effectively preventing the first wire 205 and the second wire 206 from being damaged by excessive clamping force, better protection, and increased convenience.

[0038] Working principle: When the outer side of the protective layer 104 is subjected to pressure during detection, the PI film 101 can be easily deformed, so that the PI film 101 can be easily deformed to squeeze the top of the hollow shell-shaped porous PDMS support 2. When squeezing the hollow shell-shaped porous PDMS support 2, the sliding block 202 slides along the inside of the sliding groove 102, which can easily make the first inductance coil 203 and the second inductance coil 204 in a parallel state during the deformation process, making the measurement process more accurate, increasing practicality, and improving the accuracy of pressure measurement. It can make the functional elements in the inductive sensor so that the two parallel opposing micro The planar inductor coils are infinitely close, which is more conducive to improving the flexibility and elasticity of the entire flexible PDMS sponge and the sensitivity of the sensor. The inductance changes by the mutual proximity between the first inductor coil 203 and the second inductor coil 204, and the pressure is detected by the changed data. The radiation-proof cloth 103 is made of silver fiber fabric, which can effectively blend metal fiber and cloth fiber to form a metal mesh, which can conveniently play a role in radiation protection. At the same time, it is made of polyethylene plastic, which is convenient for wear resistance. The surface can be conveniently treated for wear resistance during the detection and extrusion process, making it more convenient to use and increasing the service life.

[0039] By rotating the rotating disk 409, the screw rod 407 can be driven to rotate synchronously, so that the screw rod 407 can move along the fixing frame 408 to the inner side of the fixing block 404, which can easily make the extrusion blocks 405 approach each other, clamping and fixing the first wire 205 and the second wire 206, making it more stable during the clamping process. The extrusion block 405 can be used to conveniently clamp, and the protective pad 406 can be used to protect the first wire 205 and the second wire 206, effectively preventing the clamping force The invention can prevent the first wire 205 and the second wire 206 from being damaged by excessive pulling force, and prevent the wires from falling off and breaking due to excessive pulling force from the outside, thereby increasing practicality and convenience. The movable shaft 303 can be used to conveniently flip the first clamping block 4 and the second clamping block 401, and the fixed knob 403 and the docking rod 402 are used to limit the fixation, so that the first clamping block 4 and the second clamping block 401 are more convenient to install, which makes the installation process more convenient and increases practicality.

[0040] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0041] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil, comprising a flexible substrate (1), a hollow shell porous PDMS support (2) and a mounting frame (3), characterized in that: A hollow shell-shaped porous PDMS support (2) is fixed on the upper limit of the flexible substrate (1), a PI film (101) that matches the flexible substrate (1) is adhered to the top of the hollow shell-shaped porous PDMS support (2), and the outer sides of the flexible substrate (1) and the PI film (101) are wrapped with a radiation-proof cloth (103), and a first inductor coil (203) and a second inductor coil (204) are fixedly installed on the inner wall of the hollow shell-shaped porous PDMS support (2), and the outer sides of the first inductor coil (203) and the second inductor coil (204) are electrically connected to a first wire (205) and a second wire (206) extending from the hollow shell-shaped porous PDMS support (2), respectively, and a mounting frame (3) is fixedly installed on the outer side of the flexible substrate (1); The outer side of the mounting frame (3) is fixedly connected to a fixing rod (301), and the top and bottom of the fixing rod (301) are movably mounted with a first clamping block (4) and a second clamping block (401), one side of the first clamping block (4) and the second clamping block (401) is fixedly mounted with a fixing block (404), the inner side of the fixing block (404) is spirally mounted with an extrusion block (405) via a screw rod (407), and the outer side of the fixing block (404) is fixedly mounted with a fixing frame (408) that cooperates with the screw rod (407); The flexible base liner (1) and the hollow shell-shaped porous PDMS support body (2) are fixed in position by the mounting groove (106), and the flexible base liner (1) is flush with the top of the hollow shell-shaped porous PDMS support body (2); The PI film (101) is yellow and transparent, and is made of insulating material.

2. The hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil according to claim 1, characterized in that: The radiation-proof cloth (103) is made of silver fiber fabric, and the surface of the radiation-proof cloth (103) is covered with a protective layer (104).

3. The hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil according to claim 2, characterized in that: The outer side of the protective layer (104) is wrapped with a wear-resistant layer (105), and the material of the wear-resistant layer (105) is made of polyethylene plastic.

4. The hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil according to claim 1, characterized in that: The hollow shell-shaped porous PDMS support (2) and the flexible base liner (1) are slidably mounted via a sliding block (202), and the inner wall of the flexible base liner (1) is provided with a sliding groove (102) that cooperates with the sliding block (202).

5. The hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil according to claim 1, characterized in that: The hollow shell-shaped porous PDMS support (2) is adhered and fixed to the first inductor coil (203) and the second inductor coil (204) by means of adhesive tape (201), and the first inductor coil (203) and the second inductor coil (204) are installed in parallel and opposite relation.

6. The hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil according to claim 1, characterized in that: The top and bottom of the fixing rod (301) are both welded with a mounting seat (302), and the mounting seat (302) and the first clamping block (4) and the second clamping block (401) are movably mounted via a movable shaft (303).

7. The hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil according to claim 1, characterized in that: The first clamping block (4) and the second clamping block (401) are fixed via a fixing knob (403), and a docking rod (402) that cooperates with the fixing knob (403) is fixedly installed on the inner side of the second clamping block (401).

8. The hollow shell PDMS flexible pressure sensing device with an embedded planar inductor coil according to claim 1, characterized in that: A protective pad (406) is adhered to the inner side of the extrusion block (405), and a rotating disk (409) is welded to the outer side of the screw rod (407).

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