Capacitive flexible pressure sensor and human body monitoring equipment

Abstract

The utility model provides a capacitive flexible pressure sensor and a human body monitoring device. The capacitive flexible pressure sensor comprises two groups of electrode layers arranged at intervals and a dielectric layer arranged in a space between the two groups of electrode layers, the dielectric layer comprises a plurality of connecting units, and each connecting unit comprises a first springback structure and a second springback structure; the second springback structure comprises second elastic pieces arranged on the opposite sides of the two sets of electrode layers respectively, and the two second elastic pieces are oppositely arranged and arranged at the nearest point of the two second elastic pieces at a proper distance; the first springback structure comprises a first elastic piece directly connected with the electrode layers at the two ends. According to the capacitive flexible pressure sensor, supporting force grading setting is achieved through the second elastic piece which is not directly connected. In the initial stage of compression, the first elastic piece plays a role, the sensor has high sensitivity, the first and second rebound structures act simultaneously after further compression, and the range of the sensor is expanded. The sensor has the advantages of high sensitivity and wide detection range.

Description

Technical Field

[0001] The utility model relates to the technical field of flexible pressure sensors, in particular to a capacitive flexible pressure sensor and human body monitoring equipment. Background Art

[0002] In recent years, with the rapid development and unprecedented innovation of artificial intelligence, the application scenarios and development market of flexible electronics have been broadened. Flexible pressure sensors are one of the core components of flexible electronic products, and are used in the current popular fields of human motion monitoring, virtual reality interaction, intelligent health management, intelligent robots, etc. Flexible pressure sensors are usually divided into four working mechanisms, namely piezoresistive, capacitive, piezoelectric or triboelectric. Capacitive pressure sensors have the advantages of simple structure, good repeatability, high sensitivity, fast response speed and small hysteresis.

[0003] At present, the research on flexible pressure sensors at home and abroad is mainly about obtaining better sensing performance by changing the structure and materials of the dielectric layer. Different application environments have different performance requirements for sensors: in intelligent health management, high sensitivity is required to detect tiny changes in life signals; in human motion monitoring, sensors need to be easy to bend, have good stability, and have a wide detection range; in the field of intelligent interaction, sensors need to have high sensitivity, a wide detection range, and be easy to integrate.

[0004] However, there are two main shortcomings of sensors at home and abroad: First, high-sensitivity sensors are often accompanied by complex and high-cost manufacturing processes, and the introduction of precision equipment and chemical materials in the manufacturing process limits their large-scale promotion and application; second, it is difficult for flexible pressure sensors to have both high sensitivity and a wide detection range. In a single structure, the two properties often affect each other, thus limiting the application scenarios of the sensor. The current pressure detection range of capacitive flexible sensors is determined by the performance of the elastic structure and is also related to the measurement accuracy of the polar capacitance. However, after pursuing a large measurement range, it is difficult to guarantee the response sensitivity of the sensor. That is, the sensor performs poorly when a small pressure is applied or the initial load is applied. Utility Model Content

[0005] In order to solve the problem that the existing capacitive flexible pressure sensor and human body monitoring equipment cannot take into account both wide range and high sensitivity, the utility model provides a capacitive flexible pressure sensor and human body monitoring equipment.

[0006] The utility model provides a capacitive flexible pressure sensor, comprising two sets of electrode layers arranged at intervals and a dielectric layer arranged in the space between the two sets of electrode layers, wherein the dielectric layer elastically connects the two sets of electrode layers;

[0007] The dielectric layer includes a plurality of connection units connecting two groups of electrode layers, and the connection units include a first rebound structure and a second rebound structure;

[0008] The second rebound structure includes second elastic members respectively arranged on opposite sides of the two sets of electrode layers, the two second elastic members are arranged opposite to each other and are arranged at a proper distance from each other at their closest points;

[0009] The first resilient structure includes a first elastic member directly connected to the electrode layers at both ends.

[0010] Preferably, the second elastic member is a concentric arc segment with equal diameter, and the first elastic member is a multi-section bent structure or a spiral structure.

[0011] Preferably, the connection units are vertically and horizontally arranged, and a plurality of the connection units are symmetrically and staggeredly arranged in a uniform array between the two groups of electrode layers.

[0012] Preferably, the connection unit includes fixed beams at both ends, the two groups of fixed beams respectively connect the two groups of electrode layers, half of the thickness of the second elastic member structure is tangent to a straight line half of the thickness of the fixed beam structure, and the second elastic member is partially integrated with the surface of the fixed beam.

[0013] Preferably, the first elastic member is composed of a plurality of connected fold line segments, and the structure is vertically symmetrical to form three inwardly concave fold angles.

[0014] Preferably, the arc radius corresponding to the second elastic member is θ 1 and θ 2 The corresponding arcs from the inflection point of the inflection line segment of the first elastic member to the center of the circle are 10~20°, 30°, 40°, 20°, 20°, 40°, 30°, and 10~20° respectively.

[0015] Preferably, the distance ratios from the inflection point of the inflection line segment of the first elastic member to the center of the circle are as follows: d 1 : d 2 : d 3 : d 4 : d 5 : d 6 : d 7 : d 8 : d 9 : d 10 : d 11=14: 14 : 15 : 10 : 14 : 6 : 14 : 10 : 15 : 14 : 14, and d 1 = R , R is the radius of the second elastic member.

[0016] Preferably, the electrode layer comprises an upper substrate, a conductive electrode and a lower substrate, wherein the conductive electrode is disposed between the upper substrate and the lower substrate.

[0017] Preferably, the structural thickness and width of the fixed beam, the first rebound structure and the second rebound structure are equal; a plurality of connecting units are arranged in a symmetrical and staggered uniform array, and the unit structure thickness is D , the unit structure spacing is L ,and D : L =3: 2.

[0018] The utility model provides a human body monitoring device, comprising any one of the above-mentioned capacitive flexible pressure sensors.

[0019] The utility model connects two electrode layers through a connecting unit having a first rebound structure and a second rebound structure. Since the second rebound structure has a second elastic member that is not directly connected to the contact. Therefore, in the early stage of compression of the electrode layer, the first elastic member plays a role, and the capacitive flexible pressure sensor has a high detection sensitivity. After further compression, the second rebound structure and the first rebound structure play a role at the same time, achieving the goal of expanding the range of the capacitive flexible pressure sensor. The sensor has the advantages of high sensitivity, wide detection range, good stability, short response time, small hysteresis, long service life and simple preparation.

[0020] Compared with related technologies, the dielectric layer structure of this capacitive flexible pressure sensor will gradually shrink like an armadillo when pressure is applied, shrinking into a circle and then slowly flattened. Therefore, the sensor will form a two-level structure when subjected to different pressures. The first level is in the low-pressure range, and the broken line structure will be compressed and deformed. Since the broken line structure has a discontinuous shape, it causes a large stress concentration, making it susceptible to large shear stress, resulting in weak resistance to external forces, which makes the sensor have a higher sensitivity in the low-pressure range. The second level is in the high-pressure range, the broken line structure shrinks and closes, and the arc contact is subjected to stress. Under the joint action of the broken line structure and the arc, it has a higher bearing capacity in the high-pressure range and can detect a larger pressure range. And the middle broken line structure is similar to a spring structure and has a shorter response time.

[0021] Secondly, compared with the traditional capacitor structure, the embodiment of the present invention has higher sensitivity in the low pressure range, a larger pressure detection range, short response time and other excellent characteristics; when applied to human motion monitoring, the sensor can sensitively detect changes in weak vital signals such as breathing, and can also detect changes in a large pressure range during plantar movement, and is more adaptable to human motion within various pressure ranges. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an overall schematic diagram of the capacitive flexible pressure sensor of the utility model;

[0023] Figure 2 , 3 is a schematic structural diagram of the connecting unit 21;

[0024] Figure 4 , 5 This is a working schematic diagram of the capacitive flexible pressure sensor of the utility model;

[0025] Figure 6 It is a schematic diagram of the assembly of the utility model;

[0026] Figure 7 It is the sensitivity curve of the capacitive flexible pressure sensor of the utility model;

[0027] Figure 8 It is the hysteresis curve of the capacitive flexible pressure sensor of the utility model;

[0028] Fig. 9 It is the minimum resolution curve of the capacitive flexible pressure sensor of the utility model;

[0029] Fig.10 It is the response time curve of the capacitive flexible pressure sensor of the utility model;

[0030] Fig.11 It is the repeatability test response curve of the capacitive flexible pressure sensor of the utility model;

[0031] Fig.12 The structural thickness of the capacitive flexible pressure sensor of the utility model is used to explore the influence curve on the sensor performance;

[0032] Fig.13 This is a curve showing the influence of the curvature of the second elastic member of the capacitive flexible pressure sensor of the present utility model on the sensor performance.

[0033] In the figure:

[0034] 1: electrode layer; 11: upper substrate; 12: conductive electrode; 13: lower substrate; 2: dielectric layer; 21: connecting unit; 22: fixed beam; 23: first rebound structure; 24: second rebound structure; 241: first elastic member; 242: second elastic member. DETAILED DESCRIPTION

[0035] The following is a detailed description of the present invention in conjunction with the accompanying drawings and specific embodiments. In this specification, the size ratios in the drawings do not represent the actual size ratios, but are only used to reflect the relative position relationship and connection relationship between the components. Components with the same name or the same number represent similar or identical structures and are only for illustrative purposes.

[0036] Figure 1 The capacitive flexible pressure sensor of the utility model is an overall schematic diagram. The capacitive flexible pressure sensor has a bionic armadillo structure, which includes two sets of electrode layers 1 arranged at intervals, and a dielectric layer 2 is arranged in the space between the two sets of electrode layers 1, and the dielectric layer 2 connects the two sets of electrode layers. The dielectric layer 2 has resilience and can be compressed under pressure to reduce the distance between the two electrode layers 1, and recover after the pressure is released. The capacitive flexible pressure sensor realizes the function of pressure sensing by changing the capacitance between the first electrode layer 1 and the second electrode layer 3 caused by changing the distance between the first electrode layer 1 and the second electrode layer 3.

[0037] Specifically, the electrode layer 1 optionally includes an upper substrate 11, a conductive electrode 12 and a lower substrate 13, wherein the conductive electrode 12 is placed between the upper substrate 11 and the lower substrate 13. A capacitor with a variable spacing is formed between the conductive electrodes 12 on the two spaced electrode layers 1. The material of the upper substrate 11 and the lower substrate 13 can preferably use polydimethylsiloxane material. The sizes of the upper substrate 11, the conductive electrode 12 and the lower substrate 13 are preferably designed to be consistent, and when they are stacked, they form a whole with overlapping edges. The upper substrate 11 acts as a protective and shielding layer for the conductive electrode 12 of the capacitive flexible pressure sensor; the lower substrate 13 acts as a connector between the conductive electrode 12 and the dielectric layer 2, which is beneficial to structural stability. The dielectric layer 2 uses a flexible conductive material, such as a flexible conductive cloth material, which is easy to bond with the materials of other layers of the sensor, prolongs the service life and has high flexibility.

[0038] The dielectric layer 2 may include a plurality of connection units 21 connecting two groups of electrode layers 1 . Figure 2 , 3: is a structural schematic diagram of the connection unit 21, and the connection unit 21 has a bionic armadillo structure. The dielectric layer 2 has a first rebound structure 23 and a second rebound structure 24 between the fixed beams 22 connected to the electrode layers 1 at both ends. The first rebound structure 23 and the second rebound structure 24 connect the fixed beams 22 at both ends to achieve the rebound after compression between the two groups of electrode layers 1. Among them, the first rebound structure 23 is a first elastic member 241 directly connected to the electrode layers 1 at both ends to achieve the rebound control of the full compression stroke. The second rebound structure 24 is provided with a second elastic member 242 on the opposite surfaces of the two fixed beams 22. The second elastic members 242 on the two fixed beams 22 are arranged relative to each other and are spaced at an appropriate distance at the closest point. Since the two second elastic members 242 are not in direct contact with each other, but are spaced at a certain distance, once the electrode layers 1 are compressed, the dielectric layer 2 is compressed at the same time. During the compression process, the first elastic member 241 is directly connected to the electrode layer 1, so it is compressed throughout the entire process and can rebound when the pressure is lost to restore the distance between the two electrode layers 1. The second elastic member 242 is different. Since there is a certain distance between the closest points of the two second elastic members 242, in the initial stage of compression, although the distance between the electrode layers 1 decreases, due to the existence of the distance between the second elastic members 242, in the initial stage of compression, the two second elastic members 242 do not contact each other and no rebound force is generated. After further compression, the closest points of the two second elastic members 242 contact each other and begin to generate rebound force, which together with the first elastic member 241 supports and withstands the pressure between the electrode layers 1. Due to the existence of the second elastic member 242, the connection unit 21 generates two stages of different stiffness as the compression distance increases during the compression process, thereby controlling the capacitive flexible pressure sensor to have a force-electric characteristic curve different from that of the prior art.

[0039] like Figure 2 , 3 The embodiment shown. The connection unit 21 has a bionic armadillo structure, wherein the first elastic member 241 can be a multi-section bending structure or a spiral spring structure made of elastic material. The connection unit 21 preferably has a vertically symmetrical structure. Since the connection unit 21 has a first elastic member 241 and a second elastic member 242, and the shapes and working modes of the first elastic member 241 and the second elastic member 242 are different, in order to balance the force on the electrode layer 1 and make the electrode layer 1 stably and smoothly translate downward when under pressure, the connection units 21 should preferably be as follows: Figure 1 Shown are alternating symmetrical arrangements. Figure 2 , 3This is just one specific embodiment of the optional structure. In such an embodiment, the first elastic member 241 has a multi-section bending structure. The two sets of second elastic members 242 are preferably concentric arc segments of equal diameter. In order to ensure structural stability, the second elastic member 242 is tangent to the straight line of half the thickness of the structure and half the thickness of the structure of the fixed beam 22, and the second elastic member 242 and the surface of the fixed beam 22 are partially integrated.

[0040] The connection unit 21 is made of polydimethylsiloxane material, which is self-insulating, easily deformed when a load is applied, has good elasticity, and together with air forms a dielectric layer with variable dielectric parameters; the fixed beam 22 of the connection unit 21 is parallel to the electrode layer 1, and the fixed beam 22 and the conductive electrode 12 are bonded by silicone rubber.

[0041] Figure 4 , 5 The working diagram of the capacitive flexible pressure sensor of the utility model is shown in FIG. When the capacitive flexible pressure sensor is used, the first elastic member 241 in the bionic armadillo structure in the dielectric layer 2 is first subjected to stress and deformed, and the fold line segment begins to shrink and deform. When further compressed, the corner gap in the fold line structure is compressed and the second elastic member 242 begins to contact and deform. The design of the connection unit 21 structure and the change of the material overcome the disadvantage that a single structure cannot simultaneously meet high sensitivity and a wide monitoring range. At the same time, the sensor has excellent stability and a faster response speed.

[0042] The following is a scheme of a specific embodiment of the present utility model.

[0043] The fixed beam 22 of this embodiment. The first rebound structure 23 and the second rebound structure 24 have the same thickness and width. The dielectric layer includes four bionic armadillo connection units, and the connection units 21 are symmetrically staggered and evenly arranged in an array. The thickness of the connection unit is D , the connection unit spacing is L , D : L =3:2. The second elastic member 242 is an arc, and the arc has an arc radius of θ 1 and θ 2 The arc of each point of the fold line structure of the first elastic member 241 is 30~90°; θ 3 and θ 10 10~20°, θ 4 and θ 9 is 30°, θ 5 and θ 8 is 40°, θ6 and θ 7 is 20°, and θ 1 and θ 2 are equal, and θ 3 and θ 10 Equal; the 11 turning points of the broken line structure are AK, and the distances from the center of the circle are d 1 arrive d 11 , preferably, the ratio of the arc radius to the turning point of the broken line structure is R : d 1 : d 2 : d 3 : d 4 : d 5 : d 6 : d 7 : d 8 : d 9 : d 10 : d 11 =14 : 14 : 14 : 15 : 10 : 14 : 6 : 14 : 10 : 15 : 14 : 14.

[0044] A specific implementation plan is given below, and a series of performance tests and evaluations are carried out.

[0045] In this specific implementation, the thickness of the medium layer 2 bionic armadillo structure is T 1.0mm, arc radius θ 1 and θ 2 is 60°, arc θ 3 and θ 10 The radius is 15° R 7.0mm, d 1 , d 2 , d 5 , d 7 ,d 10 and d 11 7.0mm, d 3 and d 9 7.5mm, d 4 and d 8 5.0mm, d 6 3.0mm. Figure 1 , the thickness of the dielectric layer connecting unit D 3.0mm, connection unit spacing L 2.0mm. Figure 1 The upper substrate 11, the conductive electrode 12 and the lower substrate 13 are of the same size, with a length of 2.0 mm, a width of 1.8 mm and a thickness of 0.4 mm.

[0046] Reference Figure 6 , the bionic dielectric layer mold and the rectangular electrode layer substrate mold were made by 3D printing technology, polydimethylsiloxane glue was applied to the mold by spin coating and allowed to stand, then dried and cured and peeled off, and the prepared substrate was adhered to the conductive electrode made of conductive cloth material by silicone rubber to form an electrode layer. Finally, a flexible pressure sensor was formed by a layer-by-layer assembly process.

[0047] Figure 7 This is the sensitivity curve of the bionic armadillo structure capacitive flexible pressure sensor. In the pressure range of 0~300 kPa, it can be observed that there are three linear regions between the load pressure and the relative capacitance. In the pressure ranges of 0~1 kPa, 1~50 kPa and 50~300 kPa, the sensitivity of the sensor is 1.032 kPa, respectively. -1 , 0.0815 kPa -1 and 0.0175 kPa -1 .

[0048] Figure 8 In order to study the hysteresis of the capacitive flexible pressure sensor with bionic armadillo structure, the hysteresis of the sensor in the range of 0-300kPa was tested by loading and unloading pressure. The hysteresis of the sensor was only 5.79%, which has the characteristic of small hysteresis linear error.

[0049] Fig. 9 This is the minimum resolution of the bionic armadillo-structured capacitive flexible pressure sensor. When a pressure of 0.5 Pa is applied to the flexible sensor, it can be clearly distinguished, indicating that the sensor can identify pressure changes as low as 0.5 Pa.

[0050] Fig.10The response time of the capacitive flexible pressure sensor with a bionic armadillo structure was tested under a pressure of 5kPa, with loading and unloading pressure. The response time of the sensor was measured to be 40ms, and the recovery time was 40ms, indicating that the sensor has a short response time and can test dynamically changing data.

[0051] Fig.11 This is the repeatability test response curve of the capacitive flexible pressure sensor with bionic armadillo structure. The test was carried out under the pressure of 50kPa, and the dynamic cycle loading and unloading was carried out for 2000 times. The surface of the experimental structure showed that the relative capacitance change was stable under the action of long-term cyclic pressure. The sensor has excellent stability and service life.

[0052] Fig.12 In order to change the thickness of the dielectric layer structure to explore the impact on sensor performance, the 1.0 mm thick structure has a larger relative capacitance change in the medium and high voltage range than the other two structures, while the sensitivity at low pressure is comparable to that of the 0.8 mm thick structure. The 0.8 mm thickness has a high sensitivity in the low pressure range because the structure is easier to compress, but the fold line structure in the medium and high voltage range is simpler to close, resulting in a smaller relative capacitance change. On the other hand, the 1.2 mm thickness is too large, making it difficult for the fold line structure to shrink, ultimately resulting in low sensitivity and relative capacitance. It can be seen from the figure that the sensor performance is best when the thickness is 1.0 mm.

[0053] Fig.13 In order to change the curvature of the upper and lower arcs to explore the impact on sensor performance, the relative capacitance changes more when the arc is 60° under 0~300 kPa. The reason is that when the arc is 60°, it forms a synergistic effect with the middle fold line structure. When the arc is 60°, the upper and lower arcs begin to contact when the maximum angle in the fold line structure is fully contracted, and the overall structure achieves multi-level changes.

[0054] In summary, the significant advantages of the embodiments of the present invention are as follows:

[0055] 1) The embodiment of the present invention is based on a capacitive flexible pressure sensor with a bionic armadillo structure. When subjected to pressure, it presents a two-level structure. First, the folded-line structure of the dielectric layer contracts rapidly under low pressure, so the sensor has high sensitivity. When pressure is continued to be applied, the folded-line structure of the dielectric layer contracts and closes to enter the second-level structure. Under the synergistic effect of the folded-line structure of the dielectric layer and the arc structure, the sensor can withstand greater pressure. Compared with traditional pressure sensors, the present invention has the characteristics of high sensitivity, wide detection range, low hysteresis, short response time and high stability based on the bionic armadillo structure.

[0056] 2) The embodiment of the present invention is based on 3D printing technology, using polydimethylsiloxane, flexible conductive cloth and silicone rubber materials. The preparation materials are inexpensive, the 3D printing mold is reusable, the preparation process is simple and safe, and can be applied in actual production.

[0057] 3) The overall structure of the embodiment of the present invention is a flexible material, which has a wider range of applications than the traditional single-structure flexible pressure sensor. At the same time, the bionic armadillo structure capacitive flexible pressure sensor has high sensitivity, wide detection range, short response time and low hysteresis, which meets the application of human motion detection and related fields, and meets the requirements of detecting tiny life signals of the human body and motion signals with a large pressure range at the same time. The flexible sensor with pressure detection function of the present invention has a clear structure and is easy to assemble.

[0058] The above content is only a description of the preferred implementation mode of the utility model, and does not limit the scope of the utility model. Without departing from the design spirit of the utility model, various modifications and improvements made to the technical solution of the utility model by ordinary technicians in this field should fall within the protection scope determined by the claims of the utility model.

Claims

1. A capacitive flexible pressure sensor, characterized in that: It comprises two groups of electrode layers (1) arranged at intervals and a dielectric layer (2) arranged in the space between the two groups of electrode layers (1), wherein the dielectric layer (2) elastically connects the two groups of electrode layers (1); The dielectric layer (2) comprises a plurality of connection units (21) connecting the two groups of electrode layers (1), and the connection units (21) comprise a first rebound structure (23) and a second rebound structure (24); The second resilient structure (24) comprises second elastic members (242) respectively arranged on opposite sides of the two sets of electrode layers (1), the two second elastic members (242) being arranged opposite to each other and being arranged at a suitable distance at the closest point between them; The first resilient structure (23) comprises a first elastic member (241) directly connected to the electrode layers (1) at both ends.

2. The capacitive flexible pressure sensor according to claim 1, characterized in that: The two second elastic members (242) are cocentric arc segments with equal diameters, and the first elastic member (241) is a spiral structure or a multi-section bent structure.

3. The capacitive flexible pressure sensor according to claim 2, characterized in that: The connection units (21) are arranged symmetrically up and down, and a plurality of the connection units (21) are arranged in a symmetrical, staggered and uniform array between the two groups of electrode layers (1).

4. The capacitive flexible pressure sensor according to claim 2, characterized in that: The connection unit (21) comprises fixed beams (22) at two ends, two groups of the fixed beams (22) respectively connecting two groups of the electrode layers (1), half of the structural thickness of the second elastic member (242) being tangent to a straight line with half of the structural thickness of the fixed beam (22), and the surface of the second elastic member (242) and the fixed beam (22) being partially fused.

5. The capacitive flexible pressure sensor according to claim 2, characterized in that: The first elastic member (241) is composed of a plurality of connected fold line segments, and the structure is vertically symmetrical, forming three inwardly concave folded corners.

6. The capacitive flexible pressure sensor according to claim 5, characterized in that: The arc radius corresponding to the second elastic member (242) θ 1 and θ 2 is 30~90°; the corresponding arcs from the inflection point of the inflection line segment of the first elastic member (241) to the center of the circle are 10~20°, 30°, 40°, 20°, 20°, 40°, 30°, and 10~20°, respectively.

7. The capacitive flexible pressure sensor according to claim 5, characterized in that: The distance ratios from the inflection point of the inflection line segment of the first elastic member (241) to the center of the circle are as follows: d 1: d 2: d 3: d 4: d 5: d 6: d 7: d 8: d 9: d 10 : d 11 =14: 14 : 15 : 10 : 14 : 6 : 14 : 10 : 15 : 14 : 14, and d 1= R , R is the radius of the second elastic member (242).

8. The capacitive flexible pressure sensor according to claim 1, characterized in that: The electrode layer (1) comprises an upper substrate (11), a conductive electrode (12) and a lower substrate (13), wherein the conductive electrode (12) is disposed between the upper substrate (11) and the lower substrate (13).

9. The capacitive flexible pressure sensor according to claim 4, characterized in that: The structural thickness and width of the fixed beam (22), the first rebound structure (23) and the second rebound structure (24) are all equal; a plurality of connecting units (21) are arranged in a symmetrical, staggered and uniform array, and the unit structure thickness is D , the unit structure spacing is L ,and D : L =3:

2.

10. A human body monitoring device, characterized in that: It comprises a capacitive flexible pressure sensor as described in any one of claims 1 to 9.

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