A flexible thin-film resistive pressure sensor
The flexible thin-film resistive pressure sensor, designed with a cavity structure and conductive microparticles, solves the problems of insufficient sensitivity and poor stability, and achieves accurate detection of pressures from small to large, making it suitable for wearable devices and medical monitoring.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU DENUOSHU ELECTRONICS CO LTD
- Filing Date
- 2025-09-19
- Publication Date
- 2026-06-30
AI Technical Summary
Existing flexible thin-film resistive pressure sensors suffer from insufficient sensitivity, limited response range, and poor long-term stability.
It adopts a cavity structure, conductive microparticles and resistance gradient design, combined with fully flexible material stacking, using upper and lower flexible conductive thin film layers made of conductive polymer materials or metal nanowire composite materials, coupled with arrayed protruding units and elastic insulating isolation layers, and the protective layer is made of polyethylene terephthalate or polyimide materials.
It achieves precise detection from minute physiological signals to large mechanical pressures, breaking through the range limitations of traditional sensors, ensuring no failure under repeated deformation, and is suitable for scenarios such as medical patches and electronic skin.
Smart Images
Figure CN224435611U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of pressure sensor technology, and in particular to a flexible thin-film resistive pressure sensor. Background Technology
[0002] A flexible thin-film resistive pressure sensor is a flexible electronic device that converts pressure signals into changes in resistance. Its core feature lies in the combination of a flexible substrate and a thin-film structure. Its working principle is that when external pressure is applied to the sensor surface, the sensitive thin film deforms, causing changes in its internal conductive pathways (such as increased interparticle spacing or reduced contact points), thereby resulting in a change in resistance. The amount of resistance change has a specific functional relationship with the magnitude of the pressure (such as a linear or exponential relationship).
[0003] With the development of flexible electronics technology, flexible pressure sensors have shown broad application prospects in wearable devices, medical monitoring, human-computer interaction and other fields. Traditional resistive pressure sensors mostly use conductive composite materials or microstructure electrodes to achieve pressure detection, but they have problems such as insufficient sensitivity, limited response range and poor long-term stability. Therefore, we propose a flexible thin film resistive pressure sensor. Utility Model Content
[0004] In view of the problems of insufficient sensitivity, limited response range and poor long-term stability of existing resistive pressure sensors, this utility model is proposed.
[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:
[0006] A flexible thin-film resistive pressure sensor includes an upper flexible conductive thin-film layer, a lower flexible conductive thin-film layer, a spacer support structure, an elastic insulating isolation layer, and a protective layer.
[0007] The upper surface of the upper flexible conductive film layer is provided with a protective layer, the spacer support structure is disposed between the upper flexible conductive film layer and the lower flexible conductive film layer and forms a cavity structure, and the elastic insulating isolation layer covers the lower surface of the lower flexible conductive film layer.
[0008] As a technical solution of the flexible thin-film resistive pressure sensor of this utility model, the upper flexible conductive thin film layer and the lower flexible conductive thin film layer are made of conductive polymer material or metal nanowire composite material, with a thickness of 10-200μm, so as to take into account both flexibility and conductivity requirements, while providing high conductivity and deformation adaptability.
[0009] As a technical solution of the flexible thin-film resistive pressure sensor of this utility model, the resistance values of the upper flexible conductive thin film layer and the lower flexible conductive thin film layer are greater than 1MΩ in the no-pressure state and less than 1kΩ in the maximum pressure state, so as to ensure that small pressures can be detected and support large pressure scenarios.
[0010] As a technical solution of the flexible thin-film resistive pressure sensor of this utility model, the spaced support structure includes an array of raised units, the raised units having a height of 0.1-2mm and a diameter of 0.5-5mm, and the spacing between adjacent raised units being 1-10mm, so as to facilitate adjustment of sensitivity and response uniformity and avoid local stress concentration.
[0011] As a technical solution for the flexible thin-film resistive pressure sensor described in this utility model, the spacer support structure is prepared by photolithography or micromolding process, and the material is photosensitive resin or elastomer material, so as to achieve micron-level structural consistency and ensure the elasticity and durability of the spacer support structure.
[0012] As a technical solution of the flexible thin-film resistive pressure sensor of this utility model, it further includes conductive microparticles disposed in the cavity structure. The particle size of the conductive microparticles is 10-100μm, so as to form an additional conductive path when under pressure and improve the resistance change gradient.
[0013] As a technical solution of the flexible thin-film resistive pressure sensor of this utility model, the elastic insulating isolation layer is made of silicone rubber or polyurethane material and has a thickness of 0.1-1mm. The lower surface of the elastic insulating isolation layer is provided with a micro-protrusion structure to provide buffering and improve response linearity.
[0014] As a technical solution for the flexible thin-film resistive pressure sensor described in this utility model, the protective layer is made of polyethylene terephthalate or polyimide material to protect the long-term stability of the sensor in complex environments.
[0015] Compared with the prior art, the present invention has at least the following beneficial effects:
[0016] 1. This utility model, by adopting a cavity structure, conductive microparticles and resistance gradient design, can achieve accurate detection from minute physiological signals to large mechanical pressures, and can break through the range limitations of traditional sensors.
[0017] 2. This utility model, by adopting a fully flexible material stacking arrangement, can ensure that it does not fail under repeated deformation. At the same time, the interval support structure set by micro-machining technology can take into account both precision and mass production feasibility, and is suitable for medical patches and electronic skin scenarios. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:
[0019] Figure 1 This is a schematic diagram of the main structure of this utility model.
[0020] Figure 2 For the present utility model Figure 1 Enlarged structural diagram at point A in the middle.
[0021] Figure 3 This is a schematic diagram of the exploded structure of this utility model.
[0022] Explanation of reference numerals in the attached figures:
[0023] In the figure: 1. Upper flexible conductive film layer; 2. Lower flexible conductive film layer; 301. Protruding unit; 4. Elastic insulating isolation layer; 5. Protective layer. Detailed Implementation
[0024] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.
[0025] Reference Figures 1-3 A flexible thin-film resistive pressure sensor is provided, which includes an upper flexible conductive thin film layer 1, a lower flexible conductive thin film layer 2, a spacer support structure, an elastic insulating isolation layer 4, and a protective layer 5.
[0026] A protective layer 5 is provided on the upper surface of the upper flexible conductive film layer 1. A spacer support structure is disposed between the upper flexible conductive film layer 1 and the lower flexible conductive film layer 2, forming a cavity structure. An elastic insulating isolation layer 4 covers the lower surface of the lower flexible conductive film layer 2. In application, the upper flexible conductive film layer 1 and the lower flexible conductive film layer 2 form a cavity with the spacer support structure to realize pressure response space. The elastic insulating isolation layer 4 enhances mechanical stability, and the protective layer 5 improves wear resistance. At the same time, the fully flexible structure fits the curved surface, making it suitable for wearable devices (such as health monitoring patches) or curved interactive interfaces.
[0027] Reference Figure 2 and Figure 3The upper flexible conductive thin film layer 1 and the lower flexible conductive thin film layer 2 are made of conductive polymer materials or metal nanowire composite materials, with a thickness of 10-200μm. In applications, the 10-200μm thickness takes into account both flexibility and conductivity requirements, while the conductive polymer / metal nanowire composite material provides high conductivity and deformation adaptability.
[0028] Reference Figure 2 and Figure 3 The resistance values of the upper flexible conductive thin film layer 1 and the lower flexible conductive thin film layer 2 are greater than 1MΩ under no pressure and less than 1kΩ under maximum pressure. In application, the resistance ranges from >1MΩ (no pressure) to <1kΩ (full pressure) to ensure that small pressures can be detected (such as pulse fluctuations) while supporting high pressure scenarios (such as gait analysis).
[0029] Reference Figure 3 The spaced support structure includes an array of raised units 301, each raised unit 301 having a height of 0.1-2mm and a diameter of 0.5-5mm. The spacing between adjacent raised units 301 is 1-10mm. In application, the array design of the raised units 301 (0.1-2mm high, 0.5-5mm diameter) adjusts the sensitivity and response uniformity through the spacing (1-10mm), avoiding local stress concentration.
[0030] Reference Figures 1-3 The spacer support structure is fabricated using photolithography or micromolding processes, and the material is photosensitive resin or elastomer. In application, photolithography / micromolding processes achieve micron-level structural consistency, while photosensitive resin / elastomer materials ensure the elasticity and durability of the spacer support structure.
[0031] Reference Figures 1-3 It also includes conductive microparticles set in the cavity structure. The particle size of the conductive microparticles is 10-100μm. In application, 10-100μm conductive microparticles (such as metal particles) are added to the cavity structure to form additional conductive paths when under pressure, thereby improving the resistance change gradient.
[0032] Reference Figure 2 and Figure 3 The elastic insulating layer 4 is made of silicone rubber or polyurethane and has a thickness of 0.1-1mm. The lower surface of the elastic insulating layer 4 has a micro-protrusion structure. In application, the silicone rubber / polyurethane material (0.1-1mm thick) provides cushioning, while the micro-protrusion structure on the lower surface disperses stress and improves the linearity of response.
[0033] Reference Figure 2 and Figure 3The protective layer 5 is made of polyethylene terephthalate or polyimide. In applications, polyethylene terephthalate / polyimide is corrosion-resistant and scratch-resistant, protecting the sensor's long-term stability in complex environments (such as contact with sweat).
[0034] The working principle of this utility model is as follows: When there is no external pressure, the upper flexible conductive film layer 1 and the lower flexible conductive film layer 2 are isolated by the protruding unit 301 of the spaced support structure and form a cavity structure. At this time, the resistance is >1MΩ (close to insulation).
[0035] When external pressure is applied, the external pressure acts on the protective layer 5 and is transmitted to the upper flexible conductive film layer 1, causing it to deform downwards. The protruding unit 301 is compressed, and the upper flexible conductive film layer 1 gradually contacts the lower flexible conductive film layer 2. As the contact area between the upper flexible conductive film layer 1 and the lower flexible conductive film layer 2 increases, the resistance value gradually decreases (from the MΩ level to the kΩ level). At the same time, the conductive particles in the cavity structure are displaced under pressure, forming additional conductive paths and accelerating the decrease in resistance.
[0036] When the pressure is removed, the micro-protrusion structure of the elastic insulating isolation layer 4, together with the spacer support structure, rebounds, restores the initial cavity, and the resistance rises back to the baseline.
[0037] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.
Claims
1. A flexible thin-film resistive pressure sensor, characterized in that: It includes an upper flexible conductive thin film layer (1), a lower flexible conductive thin film layer (2), a spacer support structure, an elastic insulating isolation layer (4), and a protective layer (5); The upper surface of the upper flexible conductive film layer (1) is provided with a protective layer (5), the spacer support structure is disposed between the upper flexible conductive film layer (1) and the lower flexible conductive film layer (2) and forms a cavity structure, and the elastic insulating isolation layer (4) covers the lower surface of the lower flexible conductive film layer (2).
2. The flexible thin-film resistive pressure sensor according to claim 1, characterized in that: The upper flexible conductive thin film layer (1) and the lower flexible conductive thin film layer (2) are made of conductive polymer material or metal nanowire composite material, with a thickness of 10-200 μm.
3. The flexible thin-film resistive pressure sensor according to claim 1, characterized in that: The resistance values of the upper flexible conductive film layer (1) and the lower flexible conductive film layer (2) are greater than 1 MΩ under no pressure and less than 1 kΩ under maximum pressure.
4. The flexible thin-film resistive pressure sensor according to claim 1, characterized in that: The spaced support structure includes arrayed protruding units (301), each protruding unit (301) having a height of 0.1-2 mm and a diameter of 0.5-5 mm, with a spacing of 1-10 mm between adjacent protruding units (301).
5. The flexible thin-film resistive pressure sensor according to claim 1, characterized in that: The spacer support structure is prepared by photolithography or micromolding, and the material is photosensitive resin or elastomer.
6. The flexible thin-film resistive pressure sensor according to claim 1, characterized in that: It also includes conductive microparticles disposed in the cavity structure, the particle size of which is 10-100 μm.
7. The flexible thin-film resistive pressure sensor according to claim 1, characterized in that: The elastic insulating isolation layer (4) is made of silicone rubber or polyurethane material and has a thickness of 0.1-1mm. The lower surface of the elastic insulating isolation layer (4) is provided with a micro-protrusion structure.
8. The flexible thin-film resistive pressure sensor according to claim 1, characterized in that: The protective layer (5) is made of polyethylene terephthalate or polyimide.