High-stability ultrathin flexible mechanical force sensor and preparation method thereof
By employing a multi-layer structure design and isolation support layer limiting technology, the viscoelastic creep and contact instability problems of ultra-thin flexible mechanical force sensors have been solved, achieving high stability and simplified manufacturing, making them suitable for wearable health monitoring and intelligent robot tactile sensing.
Patent Information
- Application Number
- CN202611554308.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-10-09
- Publication Date
- 2026-11-03
AI Technical Summary
Existing ultrathin flexible mechanical force sensors suffer from output drift due to viscoelastic creep and instability in the contact between the sensitive layer and the electrode during long-term use, which affects their repeatability and stability.
The sensor employs a multi-layer structure design, including a flexible encapsulation layer, a pressure-sensitive sensing layer, an isolation support layer, and a flexible electrode layer. The pressure-sensitive sensing layer is limited by the perforated holes in the isolation support layer, and the electrode wires are fixed with conductive tape to ensure the stability of the sensor and signal transmission.
It effectively suppresses the zero-point and full-scale output drift of the sensor, improves the repeatability and stability of the force signal response, simplifies the manufacturing process, reduces costs, and is suitable for wearable health monitoring, human-computer interaction and intelligent robot tactile perception and other fields.
Smart Images
Figure CN123028733A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of flexible tactile sensing technology, and more specifically, to a highly stable ultrathin flexible mechanical force sensor and its fabrication method. Background Technology
[0002] Ultrathin flexible mechanical force sensors, due to their lightweight, ultrathin, and conformal attachability characteristics, have broad application prospects in wearable health monitoring, human-computer interaction, tactile sensing in intelligent robots, and force measurement in medical surgery. However, achieving highly stable and repeatable force signal response while maintaining ultrathin flexibility remains one of the core technological bottlenecks for this type of sensor. Piezoresistive flexible force sensors, due to their simple structure and easy signal reading, have become the most widely researched and applied technology. Their working principle is based on the change in the resistance of the sensitive material under external force to realize the electrical output of the force signal, which has significant advantages in mass production and cost control.
[0003] However, due to their simple structural design, the performance of such sensors is highly dependent on the electrical stability of the sensing material itself and the interfacial contact state between it and the electrodes. Existing technologies widely utilize elastomeric sensing materials (such as polydimethylsiloxane, Ecoflex, thermoplastic polyurethane, etc., combined with conductive fillers) which are prone to viscoelastic creep under heavy loads. This leads to irreversible reconstruction of the conductive network within the sensing layer, causing the sensor's zero-point and full-scale outputs to drift over time, severely degrading repeatability and long-term stability. On the other hand, the sensing layer and electrode layer are typically only physically bonded or in simple laminated contact. During cyclic loading and unloading, the microstructure of the sensing layer surface dynamically changes with stress, causing continuous fluctuations in the actual contact area and contact resistance, resulting in significant differences in output signals under the same force. Existing methods for improving interfacial contact mostly rely on complex microstructure designs (such as micro-pyramids, micro-pillars, etc.), which, while effective to some extent, increase the difficulty of processing and manufacturing costs, contradicting the advantages of simple structures.
[0004] Therefore, how to effectively suppress output drift caused by viscoelastic creep and improve the contact stability between the sensitive layer and the electrode while keeping the sensor structure simple and the process convenient, so as to achieve a highly repeatable force signal response, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0005] To address the aforementioned technical problems, this invention provides a highly stable ultrathin flexible mechanical force sensor and its fabrication method, aiming to improve the stability of the ultrathin flexible sensor during long-term use.
[0006] The specific plan is as follows: The first aspect of this invention provides a highly stable ultra-thin flexible mechanical force sensor, which includes, from top to bottom, a flexible encapsulation layer, a pressure-sensitive sensing layer, an isolation support layer, and a flexible electrode layer; The flexible electrode layer includes a flexible substrate and a metal electrode formed on the surface of the flexible substrate; The pressure-sensitive sensing layer is composed of a flexible fabric matrix and a conductive filler. The isolation support layer is located between the flexible encapsulation layer and the flexible electrode layer. A through hole is formed on the isolation support layer along the thickness direction. The pressure-sensitive sensing layer is entirely contained within the through hole, and the pressure-sensitive sensing layer is in contact with the hole wall. One side surface of the pressure-sensitive sensing layer is in contact with the metal electrode. The wall of the perforated hole is used to limit the lateral movement of the pressure-sensitive sensing layer, so as to constrain the lateral deformation of the pressure-sensitive sensing layer when under pressure. The lateral movement is a planar direction perpendicular to the thickness direction.
[0007] Preferably, the flexible encapsulation layer is made of one of polyethylene terephthalate, polyimide, or polyethylene naphthalate.
[0008] Preferably, the pressure-sensitive sensing layer uses non-woven fabric as a flexible fabric matrix, and the conductive filler is a hydrophilic conductive material that can form hydrogen bonds with the non-woven fabric fibers, so as to be uniformly loaded into the flexible fabric matrix by impregnation.
[0009] Preferably, the conductive filler is selected from one or more of MXene, graphene oxide, PEDOT:PSS, or carbon nanotube / nanocellulose composites.
[0010] Preferably, the isolation support layer is made of polyethylene terephthalate, which has adhesive properties on both sides for bonding the flexible encapsulation layer and the flexible electrode layer.
[0011] Preferably, the flexible substrate of the flexible electrode layer is selected from polyethylene terephthalate, polyimide or polyethylene naphthalate, and the metal electrode has an interdigitated electrode structure and is selected from one or more combinations of silver, gold, copper, nickel, platinum, aluminum or indium tin oxide.
[0012] Preferably, the flexible substrate includes a main body area and an extension shank, the metal electrode includes an electrode body and an electrode lead-out end connected to the electrode body, the electrode body is arranged in the main body area of the flexible substrate, the electrode lead-out end is arranged on the extension shank of the flexible substrate, the electrode lead-out end is connected to a wire, and conductive tape is pasted at the connection between the wire and the electrode lead-out end to achieve stable fixation of the two, and the outer contour shape of the flexible encapsulation layer and the isolation support layer is consistent with the outer contour shape of the flexible substrate.
[0013] Preferably, the perforated hole is a round hole, and the pressure-sensitive sensing layer is circular.
[0014] The second aspect of this invention provides a method for fabricating a highly stable ultrathin flexible mechanical force sensor, used to fabricate the highly stable ultrathin flexible mechanical force sensor described in the first aspect of this invention, comprising the following steps: S1, Preparation of flexible encapsulation layer: The flexible encapsulation layer film is processed into a predetermined size and shape to obtain the flexible encapsulation layer; S2, Preparation of pressure-sensitive sensing layer: The flexible fabric substrate is processed into a predetermined size and shape, cleaned and then immersed in a conductive filler solution, so that the conductive filler is loaded on the flexible fabric substrate to obtain the pressure-sensitive sensing layer. S3, Prepare the isolation support layer: The double-sided adhesive isolation support layer substrate is processed into a predetermined size and shape, and hollow holes are formed. The size and shape of the hollow holes are consistent with the pressure-sensitive sensing layer to obtain the isolation support layer. S4, Preparation of flexible electrode layer: The flexible substrate is processed into a predetermined size and shape, and then a metal electrode is formed on one side of the flexible substrate. After annealing, the flexible electrode layer is obtained. S5, Assembly: Attach one side of the isolation support layer to the flexible electrode layer, align the metal electrode with the cutout hole, then embed the pressure-sensitive sensing layer into the cutout hole of the isolation support layer and attach it to the metal electrode. Finally, attach the other side of the isolation support layer to the flexible encapsulation layer and press it to obtain the high-stability ultra-thin flexible mechanical force sensor.
[0015] Preferably, a metal electrode is formed on one side surface of the flexible substrate using magnetron sputtering combined with mask technology.
[0016] The beneficial effects of this invention are as follows: (1) This invention uses an isolation support layer to tightly laminate and fix the pressure-sensitive sensing layer and the flexible electrode layer, effectively limiting the lateral deformation and viscoelastic creep of the pressure-sensitive sensing layer under cyclic loads and preventing irreversible reconstruction of the conductive network. At the same time, the efficient curing connection of the conductive tape at the tail end ensures the absolute stability of the electrical signal transmission path, fundamentally suppressing the drift of the sensor's zero-point and full-scale outputs, and significantly improving the repeatability of the force signal response. In addition, unlike the traditional method that relies on complex surface structures such as micro pyramids and micro pillars to improve contact, this invention uses the precise positioning of the perforated holes in the isolation support layer to keep the contact area between the pressure-sensitive sensing layer and the flexible electrode layer highly constant, effectively eliminating the micromorphological changes and contact resistance fluctuations caused by cyclic loading, and ensuring stable and reliable interface contact of the sensor.
[0017] (2) This invention cleverly utilizes the double-sided adhesiveness of the isolation support layer itself, which not only achieves insulation and physical fixation of the electrode wires, but also simultaneously completes the multi-layer integrated pressing of the flexible encapsulation layer, pressure-sensitive sensing layer, and flexible electrode layer. This eliminates the high-cost process of applying additional adhesive and preparing complex microstructures, significantly shortening the manufacturing process and facilitating large-scale mass production. In addition, the sensor of this invention uses a thin flexible substrate, abandoning the traditional stacked thickness of elastomer microstructures in the prior art. The prepared force sensor is thin and has excellent flexibility, which can perfectly fit human skin or curved machine surfaces, achieving highly stable mechanical signal detection. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the overall structure of the high-stability ultra-thin flexible mechanical force sensor of the present invention.
[0019] Figure 2 This is a schematic diagram of the cross-sectional structure of the high-stability ultrathin flexible mechanical force sensor of the present invention.
[0020] Figure 3 This is a schematic diagram (i.e., a composition diagram) of the layered assembly structure of the high-stability ultra-thin flexible mechanical force sensor of the present invention.
[0021] Figure 4 This is a schematic diagram showing the lead-out and connection of the high-stability ultra-thin flexible mechanical force sensor of the present invention.
[0022] Figure 5 This is a stability test curve of the high-stability ultra-thin flexible mechanical force sensor of the present invention under cyclic loading.
[0023] Figure 6 This is a test curve of the response time of the high-stability ultra-thin flexible mechanical force sensor of the present invention.
[0024] Figure 7 This is a real-time signal response diagram of the high-stability ultra-thin flexible mechanical force sensor of the present invention detecting a light touch of a finger.
[0025] The reference numerals in the appendix of this invention are as follows: 1. Flexible encapsulation layer; 2. Pressure-sensitive sensing layer; 3. Isolation support layer; 4. Flexible electrode layer; 41. Flexible substrate; 42. Metal electrode. Detailed Implementation
[0026] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.
[0027] Example 1: Please refer to Figure 1This embodiment provides a highly stable ultra-thin flexible mechanical force sensor, which includes, from top to bottom, a flexible encapsulation layer 1, a pressure-sensitive sensing layer 2, an isolation support layer 3, and a flexible electrode layer 4.
[0028] The flexible encapsulation layer 1 is made of polyethylene terephthalate (PET) with a thickness of 100µm. Its shape consists of a circular main body area connected to an elongated rectangular extension handle.
[0029] The pressure-sensitive sensing layer 2 is composed of a flexible fabric matrix and a conductive filler, and is circular in shape. In this embodiment, the flexible fabric matrix is a non-woven fabric, and the conductive filler is Ti3C2T. x MXene nanosheet aqueous dispersion with a concentration of 10 mg / mL, Ti3C2T x MXene nanosheet aqueous dispersion can form hydrogen bonds with nonwoven fibers and be uniformly loaded into nonwoven fabrics through impregnation.
[0030] The isolation support layer 3 is made of polyethylene terephthalate, is adhesive on both sides, and has a thickness of 225µm. Its shape is consistent with that of the flexible encapsulation layer 1, and it also has a circular main body area and an elongated rectangular extension connecting the main body area. The main body area has a circular cutout at its center, the size of which is the same as that of the pressure-sensitive sensing layer 2. The pressure-sensitive sensing layer 2 can be entirely accommodated within the cutout, and the pressure-sensitive sensing layer 2 is in contact with the wall of the cutout. When pressure is applied, the wall of the cutout provides lateral restraint for the pressure-sensitive sensing layer 2.
[0031] The flexible electrode layer 4 includes a flexible substrate 41 and a metal electrode 42 formed on the upper surface of the flexible substrate 41. The outer contour shape of the flexible substrate 41 is consistent with the outer contour shape of the flexible encapsulation layer 1 and the isolation support layer 3, and it also has a circular main body area and a long rectangular extension shank connecting the main body area. In this embodiment, the thickness of the flexible substrate 41 is 100µm, and the material is polyethylene terephthalate. The metal electrode 42 is an interdigitated electrode structure, made of silver (Ag), and formed on the upper surface of the flexible substrate 41 using magnetron sputtering technology combined with a mask. The mask has cutout areas corresponding to the pattern of the metal electrode 42. After sputtering, the mask is removed and annealed to improve the adhesion between the metal electrode 42 and the flexible substrate 41. The mask is a polyimide (PI) film. The metal electrode 42 includes an electrode body and an electrode lead connected to the electrode body. The electrode body is arranged in the main body area of the flexible substrate 41, and the electrode lead is arranged on the extension shank of the flexible substrate 41. The extended end of the isolation support layer 3 has a cutout area corresponding to the end of the electrode lead. When the isolation support layer 3 and the flexible electrode layer 4 are assembled together, the end of the electrode lead is located within the cutout area. A wire is connected to the electrode lead, and the wire extends from the cutout area to the outside. Conductive tape is pasted at the cutout area to stably fix the connection between the wire and the electrode lead to achieve electrical conductivity. This ensures the absolute stability of the electrical signal transmission path and helps suppress the drift of the sensor's zero-point and full-scale output.
[0032] The fabrication method of the aforementioned highly stable ultrathin flexible mechanical force sensor includes the following steps: S1, Prepare flexible encapsulation layer 1: Process the flexible encapsulation layer film into a predetermined size and shape to obtain flexible encapsulation layer 1.
[0033] Specifically, a 100µm thick polyethylene terephthalate film is laser-cut into a predetermined size and shape profile structure. The shape profile structure includes a circular main body area and a strip-shaped extension shank connected to the main body area. The extension shank and the main body area are integrated into one structure.
[0034] S2, Preparation of pressure-sensitive sensing layer 2: The flexible fabric substrate is processed into a predetermined size and shape. After cleaning the flexible fabric substrate, it is immersed in a conductive filler solution so that the conductive filler is loaded on the flexible fabric substrate to obtain pressure-sensitive sensing layer 2.
[0035] Specifically, nonwoven fabric was selected as the flexible fabric substrate and laser-cut into circles with a diameter of 23.5 mm. The cut nonwoven fabric was then ultrasonically cleaned twice with ethanol and deionized water, and dried in a 60°C oven. MXene aqueous dispersion was selected as the conductive filler, and the dried nonwoven fabric was completely immersed in the MXene aqueous dispersion for approximately 5 minutes, repeated twice to ensure the conductive filler was loaded onto the surface of the nonwoven fabric fibers. Finally, the fabric was removed and dried and cured in a 60°C oven to obtain the pressure-sensitive sensing layer 2 composed of MXene / nonwoven fabric.
[0036] S3, Preparation of isolation support layer 3: The double-sided adhesive isolation support layer substrate is processed into a predetermined size and shape, and hollow holes are formed. The size and shape of the hollow holes are consistent with the pressure-sensitive sensing layer 2, thus obtaining the isolation support layer 3.
[0037] Specifically, polyethylene terephthalate (PET) with a thickness of 225µm is selected as the substrate for the isolation support layer. Both sides of the substrate are adhesive and initially covered with release films, which need to be removed during assembly. The substrate is laser-cut into an integral extension shank shape, consistent with the structure of the flexible encapsulation layer 1, comprising a circular main body area and a strip-shaped extension shank connected to the main body area. The outer diameter of the circular main body area of the isolation support layer 3 is 30mm, with a 23.5mm diameter circular perforation at its center, the size of which is adapted to the pressure-sensitive sensing layer 2. The strip-shaped extension shank extends outward from one side of the main body area for subsequent bonding and alignment with the electrode lead-out ends.
[0038] S4, Prepare flexible electrode layer 4: Process flexible substrate 41 into a predetermined size and shape, then form metal electrode 42 on one side of flexible substrate 41, and obtain flexible electrode layer 4 after annealing.
[0039] Specifically, polyethylene terephthalate (PET) film is selected as the flexible substrate 41. The cleaned PET flexible substrate 41 is processed into a predetermined size and outline structure using laser cutting. This outline structure is consistent with the structure of the flexible encapsulation layer 1, including a circular main body area and a strip-shaped extension stalk connected to the main body area. Subsequently, it is repeatedly ultrasonically cleaned in anhydrous ethanol and deionized water, and then dried in a 60°C oven for 1 hour. On one side surface of the PET flexible substrate 41, a patterned silver (Ag) metal electrode 42 is deposited and formed using magnetron sputtering combined with mask technology. The metal electrode 42 includes an electrode body and an electrode lead-out end connected to the electrode body. The electrode body is arranged in the main body area of the flexible substrate 41, and the electrode lead-out end is arranged in the extension stalk of the flexible substrate 41, with the end of the electrode lead-out end extending to the tail end of the extension stalk. The deposition power of magnetron sputtering was set to 15W and the time was 150s to obtain a flexible electrode layer 4 composed of PET / Ag.
[0040] S5, Assembly: One side of the isolation support layer 3 is attached to the side of the flexible electrode layer 4 with the metal electrode 42, aligning the metal electrode 42 with the cutout holes. Then, the pressure-sensitive sensing layer 2 is embedded within the cutout holes of the isolation support layer 3 and makes contact with the metal electrode 42. Finally, the other side of the isolation support layer 3 is attached to the flexible encapsulation layer 1 and compacted to obtain the highly stable ultra-thin flexible mechanical force sensor. The overall thickness is approximately 550µm, exhibiting an ultra-thin and flexible device form.
[0041] Please see Figure 2 , Figure 2 This is a schematic cross-sectional view of the high-stability ultrathin flexible mechanical force sensor according to an embodiment of the present invention. From... Figure 2 As can be seen, this sensor adopts a multi-layered composite "sandwich" structure, which includes, from top to bottom: a flexible encapsulation layer 1 at the top, a pressure-sensitive sensing layer 2 (i.e., MXene / non-woven fabric layer) in the middle, and a flexible electrode layer 4 at the bottom. The flexible electrode layer 4 is composed of a flexible substrate 41 and metal electrodes 42 disposed on its surface. An isolation support layer 3 is provided at the edge region, its structure surrounding and covering the edge of the flexible electrode layer 4, and combined with the top flexible encapsulation layer 1, forming an effective seal and physical isolation of the middle pressure-sensitive sensing layer 2, thereby ensuring the sensor's ultra-high stability and ultra-thin characteristics.
[0042] Please see Figure 3 , Figure 3This is a schematic diagram (i.e., a composition diagram) of the layered assembly structure of the high-stability ultra-thin flexible mechanical force sensor according to an embodiment of the present invention. The sensor is mainly composed of three key materials: polyethylene terephthalate (PET) (light blue), Ag (silver gray, referring to metal electrode 42), and MXene / non-woven fabric (grayish black). In terms of assembly, the top and bottom layers are both polyethylene terephthalate (PET); the middle layer is a circular MXene / non-woven fabric sensitive material. The Ag metal electrode 42 prefabricated on the bottom polyethylene terephthalate (PET) film has an interdigitated structure and extends two parallel lead ends for subsequent electrical connections.
[0043] Please see Figure 4 , Figure 4 This is a schematic diagram of the lead-out and connection of the high-stability ultra-thin flexible mechanical force sensor according to an embodiment of the present invention. The bottom structure (i.e., the flexible electrode layer 4) mainly consists of a flexible substrate 41 and a metal electrode 42. The metal electrode 42 is a comb-shaped electrode, connected to the lead end at the end via an extension handle. At the lead end, red and black external wires are used to electrically connect to the ends of the two lead ends respectively, realizing the connection between the internal metal electrode 42 of the sensor and the external signal acquisition circuit. This structure can convert the mechanical deformation generated by pressure into a sensing electrical signal and output it outward. In addition, the isolation support layer 3 extends and covers the tail end of the extension handle, which can effectively provide physical support and protection for the delicate metal electrode 42 circuit, preventing circuit breakage due to bending or friction during use, thereby significantly improving the stability of the sensor in long-term use.
[0044] Please see Figure 5 , Figure 5 This is a stability test curve of the high-stability ultra-thin flexible mechanical force sensor according to an embodiment of the present invention under cyclic loading. The figure shows the resistance change rate (ΔR / R0) curve of the sensor under more than 600 cyclic loading tests under a periodic pressure of approximately 15 kPa. Throughout the continuous cyclic test, the resistance change signal of the sensor maintained a high degree of amplitude consistency and good waveform reproducibility, with no obvious signal drift or attenuation, demonstrating that the sensor has excellent mechanical stability.
[0045] Please see Figure 6 , Figure 6 This is a response time test curve of the high-stability ultrathin flexible mechanical force sensor according to an embodiment of the present invention. From... Figure 6 As can be seen, the sensor's response time under force is approximately 0.16s, and its recovery time after the external force is removed is approximately 0.08s, demonstrating rapid response and recovery characteristics (millisecond level). This indicates that the sensor can accurately capture transient mechanical changes and possesses excellent dynamic sensing performance.
[0046] Please see Figure 7 , Figure 7 This is a real-time signal response diagram of a highly stable ultra-thin flexible mechanical force sensor detecting a light finger touch, according to an embodiment of the present invention. During multiple consecutive light finger touches, the sensor signal waveform remained consistent, with no significant baseline drift, and good repeatability and consistency among the response peaks. This indicates that the sensor can stably and sensitively capture external mechanical stimuli, demonstrating excellent practical application performance in real-time tactile perception in wearable electronic devices and human-computer interaction.
[0047] Example 2: This example is improved based on Example 1 as follows: the metal electrode 42 in step S4 is replaced with one or more of the following: silver (Ag) target material: gold (Au), copper (Cu), nickel (Ni), platinum (Pt), aluminum (Al) or indium tin oxide (ITO). Those skilled in the art can adaptively adjust the deposition power and time of magnetron sputtering according to the type of target material selected. The remaining preparation steps are exactly the same as in Example 1.
[0048] In addition, the following alternative can be used in this embodiment: replace the conductive filler in step S2 with one or more of the following: graphene oxide aqueous dispersion, PEDOT:PSS (poly(3,4-ethylenedioxythiophene): polystyrene sulfonate) aqueous solution or carbon nanotube / nanocellulose composite aqueous dispersion, and keep the rest of the preparation method the same as in Example 1.
[0049] Alternatively, the flexible substrate 41 in step S4 can be replaced with a polyimide (PI) film or a polyethylene naphthalate (PEN) film instead of a polyethylene terephthalate (PET) film.
[0050] The three replacement schemes mentioned above can be implemented individually or in any combination.
[0051] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or step transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.
Claims
1. A highly stable, ultra-thin, flexible mechanical force sensor, characterized in that, From top to bottom, it includes a flexible encapsulation layer (1), a pressure-sensitive sensing layer (2), an isolation support layer (3), and a flexible electrode layer (4). The flexible electrode layer (4) includes a flexible substrate (41) and a metal electrode (42) formed on the surface of the flexible substrate (41). The pressure-sensitive sensing layer (2) is composed of a flexible fabric matrix and a conductive filler. The isolation support layer (3) is located between the flexible encapsulation layer (1) and the flexible electrode layer (4). A hollow hole is formed on the isolation support layer (3) through the thickness direction. The pressure-sensitive sensing layer (2) is entirely contained in the hollow hole, and the pressure-sensitive sensing layer (2) is in contact with the hole wall of the hollow hole. One side surface of the pressure-sensitive sensing layer (2) is attached to the metal electrode (42). The hole wall of the hollowed-out hole is used to provide lateral restraint on the pressure-sensitive sensing layer (2) to constrain the lateral deformation of the pressure-sensitive sensing layer (2) when it is under pressure. The lateral direction is a planar direction perpendicular to the thickness direction.
2. The high-stability ultrathin flexible mechanical force sensor according to claim 1, characterized in that, The flexible encapsulation layer (1) is made of one of polyethylene terephthalate, polyimide, or polyethylene naphthalate.
3. The high-stability ultrathin flexible mechanical force sensor according to claim 1, characterized in that, The pressure-sensitive sensing layer (2) uses non-woven fabric as a flexible fabric matrix, and the conductive filler is a hydrophilic conductive material that can form hydrogen bonds with the non-woven fabric fibers, and is uniformly loaded into the flexible fabric matrix by impregnation.
4. The high-stability ultrathin flexible mechanical force sensor according to claim 3, characterized in that, The conductive filler is selected from one or more of MXene, graphene oxide, PEDOT:PSS, or carbon nanotube / nanocellulose composites.
5. The high-stability ultrathin flexible mechanical force sensor according to claim 1, characterized in that, The isolation support layer (3) is made of polyethylene terephthalate and has adhesive properties on both sides, which is used to bond the flexible encapsulation layer (1) and the flexible electrode layer (4).
6. The high-stability ultrathin flexible mechanical force sensor according to claim 1, characterized in that, The flexible substrate (41) of the flexible electrode layer (4) is made of polyethylene terephthalate, polyimide or polyethylene naphthalate, and the metal electrode (42) is an interdigitated electrode structure, and is made of one or more combinations of silver, gold, copper, nickel, platinum, aluminum or indium tin oxide.
7. The high-stability ultrathin flexible mechanical force sensor according to claim 1, characterized in that, The flexible substrate (41) includes a main body area and an extension shank. The metal electrode (42) includes an electrode body and an electrode lead-out end connected to the electrode body. The electrode body is arranged in the main body area of the flexible substrate (41), and the electrode lead-out end is arranged on the extension shank of the flexible substrate (41). The electrode lead-out end is connected to a wire, and conductive tape is pasted at the connection between the wire and the electrode lead-out end to achieve stable fixation of the two. The outer contour shape of the flexible encapsulation layer (1) and the isolation support layer (3) is consistent with the outer contour shape of the flexible substrate (41).
8. The high-stability ultrathin flexible mechanical force sensor according to claim 1, characterized in that, The perforated hole is a round hole, and the pressure-sensitive sensing layer (2) is circular.
9. A method for fabricating a highly stable ultrathin flexible mechanical force sensor, characterized in that, The method for preparing the high-stability ultrathin flexible mechanical force sensor according to any one of claims 1 to 8 comprises the following steps: S1, Prepare flexible encapsulation layer (1): Process the flexible encapsulation layer film into a predetermined size and shape to obtain flexible encapsulation layer (1). S2, Preparation of pressure-sensitive sensing layer (2): The flexible fabric substrate is processed into a predetermined size and shape, cleaned and then immersed in a conductive filler solution, so that the conductive filler is loaded on the flexible fabric substrate to obtain pressure-sensitive sensing layer (2). S3, Prepare the isolation support layer (3): The double-sided adhesive isolation support layer substrate is processed into a predetermined size and shape, and hollow holes are formed. The size and shape of the hollow holes are consistent with the pressure-sensitive sensing layer (2) to obtain the isolation support layer (3). S4, Prepare flexible electrode layer (4): Process flexible substrate (41) into predetermined size and shape, and then form metal electrode (42) on one side of flexible substrate (41), and obtain flexible electrode layer (4) after annealing. S5, Assembly: Place one side of the isolation support layer (3) with the flexible electrode layer (4), align the metal electrode (42) with the cutout hole, then embed the pressure-sensitive sensing layer (2) into the cutout hole of the isolation support layer (3) and place it with the metal electrode (42). Finally, place the other side of the isolation support layer (3) with the flexible encapsulation layer (1) and press it to obtain the high-stability ultra-thin flexible mechanical force sensor.
10. The method for fabricating a high-stability ultrathin flexible mechanical force sensor according to claim 9, characterized in that, Metal electrodes (42) are formed on one side surface of the flexible substrate (41) by magnetron sputtering combined with mask technology.