Thin film six-dimensional force sensing unit and signal decoupling method thereof
Patent Information
- Application Number
- CN202611177545.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-05
- Publication Date
- 2026-09-08
AI Technical Summary
[0003]现有的六维力传感技术主要依赖应变片、电磁感应等传统测量原理，其实现方式通常需要构建复杂的三维机械结构，导致传感器整体呈现块状或柱状形态，体积大、厚度厚，不仅难以微型化，也无法像皮肤一样贴合于机器人手指或手术器械等狭窄、曲面空间表面，更难以实现大面积阵列化集成
本申请实施例提出的薄膜式六维力传感单元，第一方面，本申请摒弃了传统六维力传感器所需的复杂立体构件，将力传递与感知功能集成在超薄、可弯曲的薄膜层状结构中，使得传感单元整体厚度极小（可控制在毫米甚至亚毫米级），能够像皮肤一样贴附于机器人灵巧手、手术器械或人机交互界面的复杂曲面之上，解决了块状传感器在狭窄空间内难以集成和难以分布式布设的难题。第二方面，本申请通过非旋转对称的微纹理结构在不同方向外力下产生方向依赖性的微观形变，将六维力（包括三个力分量和三个力矩分量）编码为多个传感节点上可区分的非均匀压力分布，再借助分区电容信号进行捕捉，从而使原本仅能感知法向压力的柔性薄膜传感器具备了同时感知剪切力和扭矩的能力，突破了薄膜传感器无法实现全六维力感知的物理局限。
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Figure CN122708991A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of sensor technology, and in particular to a thin-film six-dimensional force sensing unit and its signal decoupling method. Background Technology
[0002] With the rapid development of robotic dexterity, precision assembly, and human-computer interaction, the demand for flexible sensors capable of adhering to complex curved surfaces and achieving distributed force perception is becoming increasingly urgent. Six-dimensional force sensors, as core components for robot force control and perception, have significant application value in intelligent equipment.
[0003] Existing six-dimensional force sensing technologies mainly rely on traditional measurement principles such as strain gauges and electromagnetic induction. Their implementation usually requires the construction of complex three-dimensional mechanical structures, resulting in sensors that are blocky or columnar in shape, large in size and thick. This makes them difficult to miniaturize, and they cannot be attached to narrow, curved surfaces such as robotic fingers or surgical instruments like skin. Furthermore, it is difficult to achieve large-area array integration.
[0004] While lightweight sensors, represented by flexible thin films, offer advantages such as ultra-thinness and flexibility, from a physical perspective, conventional flexible thin film sensors can only sense normal pressure and cannot directly measure shear force, let alone decouple the torque components of the three axes. Most existing three-dimensional force flexible sensor solutions on the market achieve decoupling of shear force direction and force value through arrayed electrodes and algorithms. For example, although ion-capacitive flexible sensors improve sensitivity and signal-to-noise ratio, their sensing dimensions are still limited, and they have not yet overcome the technical bottleneck of achieving full six-dimensional force (including three force components and three torque components) sensing in thin film form.
[0005] Therefore, how to achieve effective perception and decoupling of six-dimensional spatial forces while maintaining the advantages of thin-film and flexible sensors has become an urgent technical problem to be solved. Summary of the Invention
[0006] The purpose of this application is to provide a thin-film six-dimensional force sensing unit and its signal decoupling method to solve the above-mentioned problems.
[0007] To achieve the above objectives, in a first aspect, this application proposes a thin-film six-dimensional force sensing unit, which includes: The flexible sensing layer includes at least four sensing nodes, each of which is used to convert contact pressure into a zoned capacitance signal. An elastic force transmission layer is disposed on the flexible sensing layer. The top of the elastic force transmission layer is a force-bearing surface, and at least one force-guiding column is disposed at the bottom. The lower surface of the force-guiding column is in contact with the at least four sensing nodes. The lower surface of the force guide column is processed with a non-rotationally symmetric micro-texture structure. When a six-dimensional force is applied externally to the force-bearing surface, the micro-texture structure undergoes microscopic deformation under the action of the six-dimensional force, so that the six-dimensional force is transformed into a non-uniform contact pressure distribution on the at least four sensing nodes.
[0008] In some embodiments, the microtexture structure consists of multiple micro-protrusions formed on the lower surface of the force guide post. After the multiple micro-protrusions are rotated at any angle around the central axis of the force guide post, the distribution of the micro-protrusions after rotation does not completely coincide with the distribution of the micro-protrusions before rotation.
[0009] In some embodiments, the micro-protrusions include one or more combinations of random bump textures, directional wavy patterns, or asymmetric bump arrays.
[0010] In some embodiments, when the micro protrusion includes directional wavy lines, the directional wavy lines are composed of multiple parallel wavy grooves or ridges, the wavy grooves or ridges extending in a single direction or a combination of multiple different directions.
[0011] In some embodiments, when the micro-protrusions include an asymmetric bump array, the density distribution of the bumps in the asymmetric bump array in the radial direction is non-uniform, or the size of the bumps in the asymmetric bump array varies with the radial position.
[0012] In some embodiments, when an externally applied six-dimensional force acts on the force-bearing surface, the microtexture structure undergoes microscopic deformation under the action of the six-dimensional force, transforming the six-dimensional force into a non-uniform contact pressure distribution on the at least four sensing nodes, including: When a six-dimensional force is applied externally to the force-bearing surface, the microtexture structure undergoes non-uniform compression, such as tilting, twisting, or local bulging, under the action of the six-dimensional force, causing a redistribution of the contact pressure on each of the sensing nodes.
[0013] In some embodiments, when the number of the at least four sensing nodes is four, the four sensing nodes are arranged in a uniformly divided circular layout, with adjacent sensing nodes separated by insulating gaps.
[0014] In some implementations, when the externally applied six-dimensional force is a normal force perpendicular to the force-bearing surface, the partition capacitance signals of the four sensing nodes increase proportionally. When the externally applied six-dimensional force is a shear force parallel to the force-bearing surface, a differential capacitance change occurs between the sensing node located in the direction of the shear force and the sensing node located in the direction away from the shear force. When the externally applied six-dimensional force is a torque that rotates about the normal direction of the force-bearing surface, the partition capacitance signals of the diagonal sensing nodes among the four sensing nodes change in opposite directions.
[0015] In some embodiments, the number of the force guide column is one and it is located at the center of the bottom of the elastic force transmission layer; or the number of the force guide column is multiple and they are arranged in an array corresponding to the positions of the at least four sensing nodes.
[0016] Secondly, to achieve the above objectives, this application also proposes a signal decoupling method based on the aforementioned thin-film six-dimensional force sensing unit, the signal decoupling method comprising: Multi-channel zone capacitance signals are acquired in real time through each of the aforementioned sensor nodes; Through calibration experiments, a dataset of preset multidimensional force data and corresponding multi-channel test capacitance signals is simultaneously collected to train a neural network model, enabling the neural network model to learn the nonlinear mapping relationship from capacitance signal patterns to multidimensional force information. The multi-channel partitioned capacitor signal is input into the trained neural network model, and the decoupled six-dimensional force value is output.
[0017] Compared with the prior art, the beneficial effects of this application include: The thin-film six-dimensional force sensing unit proposed in this application has two main advantages. First, it eliminates the complex three-dimensional components required by traditional six-dimensional force sensors, integrating force transmission and sensing functions into an ultra-thin, flexible, layered thin-film structure. This results in an extremely small overall thickness of the sensing unit (controllable to the millimeter or even sub-millimeter level), allowing it to adhere like skin to complex curved surfaces of robotic hands, surgical instruments, or human-computer interfaces. This solves the problem of integrating and distributing bulk sensors in confined spaces. Second, by using a non-rotationally symmetric microtexture structure to generate direction-dependent micro-deformation under external forces in different directions, this application encodes the six-dimensional force (including three force components and three torque components) into a distinguishable non-uniform pressure distribution on multiple sensing nodes. This distribution is then captured using partitioned capacitance signals, enabling the flexible thin-film sensor, which could only sense normal pressure, to simultaneously sense shear force and torque. This overcomes the physical limitation that thin-film sensors cannot achieve full six-dimensional force sensing. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.
[0019] Figure 1 This is a schematic diagram of the thin-film six-dimensional force sensing unit in one embodiment from a first-view perspective. Figure 2 This is a schematic diagram of the thin-film six-dimensional force sensing unit in one embodiment from a second perspective. Figure 3 This is a flowchart illustrating a signal decoupling method for a thin-film six-dimensional force sensing unit in one embodiment.
[0020] Explanation of reference numerals in the attached figures: 100, thin-film six-dimensional force sensing unit; 1, flexible sensing layer; 11, sensing node; 2, elastic force transmission layer; 21, force guide column. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0022] All terms used in this application (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.
[0023] For example, the terms "first," "second," etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For instance, without departing from the scope of this application, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element. Both the first element and the second element are elements, but they are not the same element.
[0024] For example, the terms "comprising" or "including" used in this application indicate the presence of features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.
[0025] As mentioned earlier, existing six-dimensional force sensing technologies mainly rely on traditional measurement principles such as strain gauges and electromagnetic induction. Their implementation usually requires the construction of complex three-dimensional mechanical structures, resulting in sensors that are blocky or columnar in shape, large in size and thick in thickness. This makes them not only difficult to miniaturize, but also impossible to fit into narrow, curved surfaces such as robotic fingers or surgical instruments like skin, and even more difficult to achieve large-area array integration.
[0026] While lightweight sensors, represented by flexible thin films, offer advantages such as ultra-thinness and flexibility, from a physical perspective, conventional flexible thin film sensors can only sense normal pressure and cannot directly measure shear force, let alone decouple the torque components of the three axes. Most existing three-dimensional force flexible sensor solutions on the market achieve decoupling of shear force direction and force value through arrayed electrodes and algorithms. For example, although ion-capacitive flexible sensors improve sensitivity and signal-to-noise ratio, their sensing dimensions are still limited, and they have not yet overcome the technical bottleneck of achieving full six-dimensional force (including three force components and three torque components) sensing in thin film form.
[0027] To address the aforementioned technical issues, this application proposes a thin-film six-dimensional force sensing unit based on a micro-textured force transmission interface and its signal decoupling method, which can achieve effective sensing and decoupling of spatial six-dimensional force while maintaining the advantages of thin-film and flexible sensors.
[0028] like Figure 1 and Figure 2 As shown, this application embodiment provides a thin-film six-dimensional force sensing unit 100. The thin-film six-dimensional force sensing unit 100 includes a flexible sensing layer 1 and an elastic force transmission layer 2 disposed on the flexible sensing layer 1.
[0029] In this embodiment, the flexible sensing layer 1 is a capacitive flexible sensor based on an ionization sensing mechanism, including at least four sensing nodes 11. Each sensing node 11, from bottom to top, includes a lower electrode layer, an ion-gel dielectric layer disposed on the lower electrode layer, and an upper electrode layer disposed on the ion-gel dielectric layer. Each sensing node 11 is used to convert contact pressure into a zoned capacitance signal.
[0030] In some implementations, such as Figure 1 As shown, there are at least four sensing nodes 11, and the four sensing nodes 11 are arranged in a uniformly divided circular layout, that is, four fan-shaped or quarter-circular electrodes with the same shape and equal area, and adjacent sensing nodes 11 are separated by an insulating gap.
[0031] In this embodiment, the elastic force transmission layer 2 is integrally molded from a flexible elastomer material, which is one of polydimethylsiloxane, silicone, thermoplastic polyurethane, or hydrogel. The top of the elastic force transmission layer 2 is the force-receiving surface, used to receive externally applied six-dimensional forces (including three force components Fx, Fy, Fz and three torque components Mx, My, Mz). At least one force-guiding post 21 is provided at the bottom of the elastic force transmission layer 2, and the lower surface of the force-guiding post 21 is in contact with at least four sensing nodes 11 of the flexible sensing layer 1.
[0032] In some embodiments, there is one force guide post 21, located at the center of the bottom of the elastic force transmission layer 2, and the central axis of the force guide post 21 coincides with the central symmetry axis of the plurality of sensing nodes 11 on the flexible sensing layer 1. In other embodiments, there are multiple force guide posts 21, which are arranged in an array corresponding to the positions of at least four sensing nodes 11, with each force guide post 21 corresponding to one sensing node 11.
[0033] like Figure 2 As shown, the lower surface of the force guide post 21 is processed with a non-rotationally symmetric micro-texture structure. When a six-dimensional force is applied externally to the force-bearing surface, the micro-texture structure undergoes microscopic deformation under the action of the six-dimensional force, so that the six-dimensional force is transformed into a non-uniform contact pressure distribution on the at least four sensing nodes.
[0034] The microtexture structure consists of multiple microscopic protrusions formed on the lower surface of the force-guiding pillar. The non-rotational symmetry of the microtexture structure means that after rotating the multiple microscopic protrusions around the central axis of the force-guiding pillar by any angle, the distribution of the microscopic protrusions after rotation does not completely coincide with the distribution before rotation. That is, the spatial distribution of the microscopic protrusions is direction-dependent; their geometric arrangement changes with the rotation angle, with different rotation angles corresponding to different distribution patterns. This non-rotational symmetry characteristic enables the microtexture structure to exhibit anisotropic mechanical responses to different six-dimensional forces.
[0035] The microtextured structure on the lower surface of the guide post 21 can be manufactured in the following ways: liquid elastomer material is poured into a mold with a textured surface, cured, and then demolded to obtain the guide post 21 with a microtextured surface; or the microtexture can be fabricated on the lower surface of the formed guide post 21 using laser etching, plasma treatment, or chemical etching methods. Specifically, the texture of the mold can be etched onto a silicon wafer using photolithography and deep reactive ion etching processes to create a micron-level textured structure, or a micron-level textured structure can be fabricated on the surface of a metal mold using femtosecond laser direct writing technology.
[0036] In some embodiments, the micro-protrusions may include one or more combinations of random bump textures, directional wavy patterns, or asymmetric bump arrays. The directional wavy pattern consists of multiple parallel wavy grooves or ridges, the wavy grooves or ridges extending in a single direction or a combination of multiple different directions (e.g., in a cross-shaped or grid-like distribution). The density distribution of bumps in the asymmetric bump array is non-uniform in the radial direction; for example, the bump density is lower near the center of the guide post 21 and higher near the edge; or the size of the bumps in the asymmetric bump array varies with radial position, for example, the bump size is larger in the central region and smaller at the edge.
[0037] When an externally applied six-dimensional force acts on the force-bearing surface of the elastic force transmission layer 2, the microtexture structure undergoes microscopic deformation under the action of the six-dimensional force, transforming the six-dimensional force into a non-uniform contact pressure distribution on the four sensing nodes 11. Specifically, when an externally applied six-dimensional force acts on the force-bearing surface, the microtexture structure undergoes non-uniform compression, such as tilting, twisting, or local bulging, under the action of the six-dimensional force, causing a redistribution of the contact pressure on each sensing node.
[0038] It should be noted that the redistribution of contact pressure does not result in macroscopic displacement due to the microtexture structure. After a stable contact is established by the normal force, the micro-protrusions are tightly adhered to the surface of sensing node 11, and macroscopic displacement is suppressed by friction. The core physical mechanism of this application is the microscopic redistribution of contact stress: when torque or shear force is applied, the tangential load and support conditions borne by each micro-protrusion change, leading to a redistribution of stress flow lines within the contact interface. This redistribution manifests as follows: in the four sensing nodes, the local pressure in some areas increases, while the local pressure in other areas decreases, and the sum of the total pressure in all zones still maintains mechanical equilibrium with the external force / torque.
[0039] Specifically, when the externally applied six-dimensional force is a normal force perpendicular to the force-bearing surface, the partition capacitance signals of the four sensing nodes increase proportionally; when the externally applied six-dimensional force is a shear force parallel to the force-bearing surface, a differential capacitance change occurs between the sensing nodes located in the direction of the shear force and the sensing nodes located in the direction away from the shear force; when the externally applied six-dimensional force is a torque rotating about the normal direction of the force-bearing surface, the partition capacitance signals of the diagonal sensing nodes among the four sensing nodes change in opposite directions.
[0040] The thin-film six-dimensional force sensing unit proposed in this application has two main advantages. First, it eliminates the complex three-dimensional components required by traditional six-dimensional force sensors, integrating force transmission and sensing functions into an ultra-thin, flexible, layered thin-film structure. This results in an extremely small overall thickness of the sensing unit (controllable to the millimeter or even sub-millimeter level), allowing it to adhere like skin to complex curved surfaces of robotic hands, surgical instruments, or human-computer interfaces. This solves the problem of integrating and distributing bulk sensors in confined spaces. Second, by using a non-rotationally symmetric microtexture structure to generate direction-dependent micro-deformation under external forces in different directions, this application encodes the six-dimensional force (including three force components and three torque components) into a distinguishable non-uniform pressure distribution on multiple sensing nodes. This distribution is then captured using partitioned capacitance signals, enabling the flexible thin-film sensor, which could only sense normal pressure, to simultaneously sense shear force and torque. This overcomes the physical limitation that thin-film sensors cannot achieve full six-dimensional force sensing.
[0041] like Figure 3As shown, this application embodiment provides a signal decoupling method for a thin-film six-dimensional force sensing unit 100, the method comprising the following steps: Step S10: Collect multi-channel partition capacitance signals in real time through each of the aforementioned sensing nodes.
[0042] In this embodiment, the sensing node refers to an independently isolated capacitance detection node in the flexible sensing layer 1, and each node can convert the contact pressure into a zone capacitance signal.
[0043] For example, when there are four sensor nodes 11, four partition capacitance signals C1, C2, C3, and C4 are acquired in real time. The original acquired partition capacitance signals may contain noise, which can be further filtered (such as low-pass filtering and median filtering) and amplified to improve the signal-to-noise ratio.
[0044] Step S20: Through calibration experiments, a dataset of preset multidimensional force data and corresponding multi-channel test capacitance signals is simultaneously collected to train a neural network model, enabling the neural network model to learn the nonlinear mapping relationship from capacitance signal patterns to multidimensional force information.
[0045] In this embodiment, the preset multidimensional force data refers to the application of a thin-film six-dimensional force sensing unit 100 onto the loading surface of a six-dimensional force / torque calibration platform. The platform programmatically applies normal forces (e.g., 0~50N, step 1N), shear forces (e.g., 0~20N, step 0.5N), and torques (e.g., 0~5Nm, step 0.1Nm) of known magnitude and direction. Simultaneously, the platform records the actual force information recorded by a high-precision six-dimensional force / torque sensor (or calibration platform), including forces (Fx, Fy, Fz) and torques (Mx, My, Mz) in three orthogonal directions. The multi-channel test capacitance signal refers to the capacitance values output by each sensing node of the thin-film six-dimensional force sensing unit 100, synchronously acquired during the calibration process. The dataset is a collection of multiple samples, each containing a pair of inputs (multi-channel test capacitance signals) and outputs (preset multidimensional force data). The dataset can be divided into a training set (70%), a validation set (15%), and a test set (15%). Nonlinear mapping refers to the complex functional relationship between capacitive signals and multidimensional forces. This is because factors such as nonlinear compression of the dielectric layer, edge effects, and crosstalk often make the relationship between capacitive signals and multidimensional forces nonlinear. Neural network models can approximate this nonlinear function by learning from a large number of samples.
[0046] The neural network model can be a lightweight three-layer fully connected network: the number of input layer nodes is the same as the number of sensor nodes 11 (e.g., 4), the number of hidden layer nodes can be 16 to 32, and the number of output layer nodes is 6 (corresponding to the six-dimensional force components). The activation function of the hidden layer is ReLU, the output layer uses a linear activation function, and the loss function is mean squared error (MSE). During training, the Adam optimizer can be used, and L2 regularization or Dropout can be introduced to prevent overfitting.
[0047] Step S30: Input the multi-path partitioned capacitor signal into the trained neural network model and output the decoupled six-dimensional force value.
[0048] In this embodiment, the trained neural network model refers to the neural network model that has been trained in step S20. The decoupled six-dimensional force value refers to the six-dimensional force / torque value output by the neural network model, in units of Newtons (N) and Newton-meters (Nm). These values are a complete description of the external contact force currently borne by the thin-film six-dimensional force sensing unit 100.
[0049] In the signal decoupling method of the thin-film six-dimensional force sensing unit proposed in this application, firstly, this application utilizes sensing nodes to collect multiple original partitioned capacitance signals in real time, and at the physical level, it inherits the encoding result of the micro-texture structure on the six-dimensional force. That is, forces of different directions and magnitudes cause non-rotationally symmetric micro-textures to undergo direction-dependent micro-deformation, thereby forming a unique non-uniform contact pressure distribution on multiple sensing nodes, thus transforming the originally mixed and coupled six-dimensional force information into a distinguishable capacitance signal pattern. Secondly, through calibration experiments, preset multi-dimensional force data and corresponding multi-channel test capacitance signals are synchronously collected to form a dataset, and a neural network model is trained to learn the nonlinear mapping relationship from capacitance signal patterns to six-dimensional force information. This avoids the difficulty of complex physical modeling of elastic body deformation and electrode response in traditional methods. Even if the micro-texture structure has manufacturing tolerances or the elastic material exhibits nonlinear mechanical behavior, the neural network can automatically fit a high-precision inverse mapping model with sufficient calibration samples. Thirdly, by using the trained model for real-time decoupling, the six-dimensional force value can be directly output by inputting the real-time collected multi-channel capacitance signals.
[0050] Compared with existing technologies, the breakthrough of this application lies in enabling flexible thin-film sensors, which could only output single-dimensional normal pressure, to achieve real-time, high-precision decoupling of six-dimensional force (including three force components and three torque components) in a thin-film form for the first time without adding any complex three-dimensional structures, through the synergy of microtexture and neural network algorithms. This retains the inherent advantages of flexible thin-film sensors, such as being ultra-thin, flexible, and easy to integrate into curved surfaces, while breaking through the traditional physical limitations of not being able to sense shear force and torque. This provides a reliable, simple, and easily large-scale deployment technical solution for dexterous force control operation of robots in narrow spaces, multi-dimensional force feedback in medical tactile diagnosis, and all-dimensional force interaction in wearable devices.
[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
[0052] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the embodiments or implementations claimed above can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.
Claims
1. A thin-film six-dimensional force sensing unit, characterized in that, The thin-film six-dimensional force sensing unit includes: The flexible sensing layer includes at least four sensing nodes, each of which is used to convert contact pressure into a zoned capacitance signal. An elastic force transmission layer is disposed on the flexible sensing layer. The top of the elastic force transmission layer is a force-bearing surface, and at least one force-guiding column is disposed at the bottom. The lower surface of the force-guiding column is in contact with the at least four sensing nodes. The lower surface of the force guide column is processed with a non-rotationally symmetric micro-texture structure. When a six-dimensional force is applied externally to the force-bearing surface, the micro-texture structure undergoes microscopic deformation under the action of the six-dimensional force, so that the six-dimensional force is transformed into a non-uniform contact pressure distribution on the at least four sensing nodes.
2. The thin-film six-dimensional force sensing unit according to claim 1, characterized in that, The microtexture structure consists of multiple micro-protrusions formed on the lower surface of the force guide column. After the multiple micro-protrusions are rotated at any angle around the central axis of the force guide column, the distribution of the micro-protrusions after rotation does not completely coincide with the distribution of the micro-protrusions before rotation.
3. The thin-film six-dimensional force sensing unit according to claim 2, characterized in that, The micro-protrusions include one or more combinations of random bump textures, directional wavy patterns, or asymmetric bump arrays.
4. The thin-film six-dimensional force sensing unit according to claim 3, characterized in that, When the micro protrusion includes directional wavy lines, the directional wavy lines are composed of multiple parallel wavy grooves or ridges, and the wavy grooves or ridges extend in a single direction or a combination of multiple different directions.
5. The thin-film six-dimensional force sensing unit according to claim 3, characterized in that, When the micro-protrusion includes an asymmetric protrusion array, the density distribution of the protrusions in the asymmetric protrusion array in the radial direction is non-uniform, or the size of the protrusions in the asymmetric protrusion array varies with the radial position.
6. The thin-film six-dimensional force sensing unit according to claim 1, characterized in that, When a six-dimensional force is applied externally to the force-bearing surface, the microtexture structure undergoes microscopic deformation under the action of the six-dimensional force, transforming the six-dimensional force into a non-uniform contact pressure distribution on the at least four sensing nodes, including: When a six-dimensional force is applied externally to the force-bearing surface, the microtexture structure undergoes non-uniform compression, such as tilting, twisting, or local bulging, under the action of the six-dimensional force, causing a redistribution of the contact pressure on each of the sensing nodes.
7. The thin-film six-dimensional force sensing unit according to claim 1, characterized in that, When the number of the at least four sensing nodes is four, the four sensing nodes are arranged in a uniformly divided circular layout, and adjacent sensing nodes are separated by insulating gaps.
8. The thin-film six-dimensional force sensing unit according to claim 7, characterized in that, When the externally applied six-dimensional force is a normal force perpendicular to the force-bearing surface, the partition capacitance signals of the four sensing nodes increase proportionally. When the externally applied six-dimensional force is a shear force parallel to the force-bearing surface, a differential capacitance change occurs between the sensing node located in the direction of the shear force and the sensing node located in the direction away from the shear force. When the externally applied six-dimensional force is a torque that rotates about the normal direction of the force-bearing surface, the partition capacitance signals of the diagonal sensing nodes among the four sensing nodes change in opposite directions.
9. The thin-film six-dimensional force sensing unit according to claim 1, characterized in that, The number of the force guide column is one and it is located at the center of the bottom of the elastic force transmission layer; or the number of the force guide column is multiple and they are arranged in an array corresponding to the positions of the at least four sensing nodes.
10. A signal decoupling method based on the thin-film six-dimensional force sensing unit according to any one of claims 1 to 9, characterized in that, The signal decoupling method includes: Multi-channel zone capacitance signals are acquired in real time through each of the aforementioned sensor nodes; Through calibration experiments, a dataset of preset multidimensional force data and corresponding multi-channel test capacitance signals is simultaneously collected to train a neural network model, enabling the neural network model to learn the nonlinear mapping relationship from capacitance signal patterns to multidimensional force information. The multi-channel partitioned capacitor signal is input into the trained neural network model, and the decoupled six-dimensional force value is output.