High-sensitivity tactile perception system based on magnetic cilia array

Abstract

The invention discloses a high-sensitivity tactile sensing system based on a magnetic cilia array, a sensor comprises the magnetic cilia array and a sensor array, and the magnetic cilia array is attached to the upper surface of the sensor array; the magnetic cilia array comprises a substrate and cilia structures which are orderly arranged and fixed on the substrate; the cilia structure is made of ecological silicone rubber mixed with magnetic powder, and a plurality of groups of sensors are adopted to form a sensor array to construct a sensing system. By optimizing the magnetization process, uniform distribution of the magnetic particles in each cilium is ensured, and the output stability and sensitivity of the sensor are improved; meanwhile, the multi-sensor array layout is adopted, and high-precision sensing of multi-dimensional tactile information such as pressure, direction and vibration is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible tactile sensors, and more particularly to a high-sensitivity tactile perception system based on a magnetic ciliary array. Background Art

[0002] Tactile sensors are key components for robots to acquire physical information about their environment and enable intelligent interaction. However, existing technologies still face numerous challenges in complex application scenarios. Traditional tactile sensors lack sensitivity, making it difficult to perceive weak mechanical signals. Their rigid structure limits their adaptability to complex curved surfaces and dynamic environments. Multimodal signals (such as pressure, sliding, and vibration) are difficult to effectively decouple, limiting their integrated sensing capabilities. Furthermore, their poor adaptability to unstructured environments severely restricts their further application in fields such as industrial automation, medical rehabilitation, and human-computer interaction.

[0003] To address these issues, researchers have developed flexible magnetic tactile sensors, drawing inspiration from the structure of biological skin. By combining the deformable properties of flexible materials with the high sensitivity of magnetic induction, they have overcome the bottlenecks of traditional technologies in sensitivity, contactless sensing, and multimodal signal decoupling. This type of sensor significantly enhances tactile response through biomimetic structural design and optimized magnetization processes. Furthermore, by combining multimodal data fusion algorithms and machine learning methods, it improves the processing and recognition of complex tactile signals. However, the sensitivity and adaptability of flexible magnetic tactile sensors still need to be improved.

[0004] Therefore, how to improve the sensitivity and adaptability of tactile sensors is an urgent problem that those skilled in the art need to solve. Summary of the Invention

[0005] In view of this, the present invention provides a high-sensitivity tactile sensing system based on a magnetic ciliary array. By optimizing the magnetization process, the uniform distribution of magnetic particles in each ciliary is ensured, thereby improving the stability and sensitivity of the sensor output. At the same time, a multi-sensor array layout is adopted to achieve high-precision perception of multi-dimensional tactile information such as pressure, direction, and vibration, further enhancing the system's adaptability and application value in complex environments.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A highly sensitive tactile sensing system based on a magnetic ciliary array includes a magnetic ciliary array and a sensor array. The magnetic ciliary array is attached to the upper surface of the sensor array. The magnetic ciliary array includes a base and a ciliary structure arranged in an orderly manner and fixed on the base. The ciliary structure is made of ecological silicone rubber mixed with magnetic powder.

[0007] Preferably, the substrate is made of polydimethylsiloxane material.

[0008] Preferably, the magnetic powder is neodymium iron boron magnetic powder.

[0009] Preferably, the method for preparing the magnetic ciliary array comprises the following steps: Step 1: Cast the substrate and partially cure; Step 2: Fix the mold on the upper surface of the substrate, fill the eco-silicone rubber mixed with magnetic powder into the mold to form the ciliary structure, and form the substrate and the ciliary structure into one piece; Step 3: The ciliary structure is solidified and demolded under the action of an external directional magnetic field to form an initial magnetic ciliary structure; Step 4: Use a magnetizer to magnetize the initial magnetic ciliary structure with a strong current to form an orderly arranged magnetic ciliary array.

[0010] Preferably, each cilium in the magnetic cilium array is 5 mm long, 0.8 mm in diameter, and the spacing between cilium is 1 mm.

[0011] Preferably, the mold is made of polymethyl methacrylate.

[0012] Preferably, the sensor array includes several groups of three-axis magnetic sensors arranged and fixed on a flexible circuit board; the three-axis magnetic sensors are arranged at intervals. Each array contains several sensing units, and the units are connected by a flexible circuit board, which can further improve the plasticity and adaptability of the tactile perception system.

[0013] Preferably, the array form of the sensor array includes a rectangular array and a square array, which are adapted to the shape of the magnetic ciliary array, and the array can capture multi-dimensional mechanical changes in a wider range.

[0014] Preferably, it also includes a signal acquisition module, through I 2 C or SPI bus to connect the sensor array to collect three-axis magnetic field data.

[0015] Preferably, it also includes a microcontroller, which is connected to the signal acquisition module, receives the collected data and processes it through a dynamic correction algorithm, and then transmits it to a computer or edge device through a serial port or WiFi; the microcontroller accesses each sensor in turn through the signal acquisition module, receives the three-axis magnetic field data of each sensor and adds a timestamp as input for subsequent algorithms.

[0016] Preferably, the dynamic correction algorithm performs zero point correction, time series smoothing, multi-channel alignment, and mutation / noise removal on the three-axis magnetic field data.

[0017] As can be seen from the above technical solution, compared with the existing technology, the present invention provides a tactile perception system based on a magnetic ciliary array. Based on the concept of skin biomimetic design, it uses ecological silicone rubber (Ecoflex) and polydimethylsiloxane (PDMS) as the base materials, and neodymium iron boron (NdFeB) magnetic powder is mixed into Ecoflex to form magnetic cilia. By optimizing the magnetization process, the magnetic particles are evenly distributed throughout each ciliary, ensuring stable and consistent magnetic response characteristics, laying the foundation for efficient tactile perception. At the same time, the system adopts a multi-sensor array layout, designing two array forms, rectangular and square, to adapt to the magnetic ciliary array, constructing a sensing system that efficiently captures external mechanical signals. It can cover a wider perception range and achieve high-precision perception of multi-dimensional tactile information such as pressure, direction, and vibration. In addition, the introduction of a dynamic correction algorithm effectively improves the signal stability and reliability when multiple sensors work synchronously. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0019] Figure 1 A schematic diagram of the rectangular sensor array structure provided by the present invention; Figure 2 This is a schematic diagram of the square sensor array structure provided by the present invention; Figure 3 A schematic diagram of the sensor array circuit structure provided by the present invention; Figure 4 A schematic diagram of the three-dimensional structure of the displacement change of the magnetic ciliary array provided by the present invention through finite element analysis; Figure 5 A side view of the displacement change of the magnetic cilia array provided by the present invention through finite element analysis; Figure 6 A schematic diagram of the three-dimensional structure of the stress distribution of the magnetic cilia array provided by the present invention through finite element analysis; Figure 7 This is a side view of the stress distribution of the magnetic cilia array provided by the present invention through finite element analysis. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] The present invention discloses a highly sensitive tactile sensing system based on a magnetic ciliary array. The system comprises a magnetic ciliary array and a sensor array. The magnetic ciliary array is attached to the upper surface of the sensor array. The magnetic ciliary array comprises a base and a ciliary structure arranged and fixed to the base. The ciliary structure is made of eco-silicone rubber mixed with magnetic powder. The combination of the magnetic ciliary array and the sensor array can effectively capture tangential force for sensing. Furthermore, the separate design of the magnetic ciliary array and the sensor array effectively reduces production and maintenance costs.

[0022] Furthermore, the substrate is made of polydimethylsiloxane material.

[0023] Furthermore, the magnetic powder is neodymium iron boron magnetic powder.

[0024] To verify the actual performance of the sensor, a series of magnetic ciliary arrays were fabricated, and their mechanical response and magnetic field variation characteristics were experimentally observed. Experimental observations found that the height of these cilia ranged from 3 mm to 8 mm, and they could adapt to complex surfaces, such as fingers or knuckles. In addition, scanning electron microscope images of the magnetic ciliary arrays revealed that the magnetic particles were evenly distributed inside the cilia, with a particle concentration of 75%. This consistency ensures that each cilia can produce a stable magnetic response, thereby ensuring the reliability of the system.

[0025] On the other hand, the method for preparing a magnetic ciliary array comprises the following steps: S1: PDMS material is cast on the substrate and partially cured by high temperature heating for 5 minutes; S2: placing the mold on the upper surface of the substrate; S3: Filling the eco-silicone rubber mixed with magnetic powder into the mold to form the ciliary structure, and the base and the ciliary structure are integrally formed; S4: Under the action of an external vector magnetic field, the magnetic particles of the ciliary structure are arranged in a set direction, and then solidified and demolded by high-temperature heating for 60 minutes to form an initial magnetic ciliary structure; S5: A magnetizer is used to magnetize the initial magnetic ciliary structure using a strong current to form an orderly arranged magnetic ciliary array.

[0026] The directional magnetic field causes the magnetic particles in the ciliary structure to align in a set direction. This manufacturing method ensures that the magnetic particles are evenly distributed in each ciliary, thereby improving the consistency and magnetic response strength of the sensor, providing reliable and consistent magnetism for effective tactile perception.

[0027] Furthermore, the mold is made of polymethyl methacrylate (PMMA) material.

[0028] Furthermore, each cilium in the magnetic cilium array is 5mm long and 0.8mm in diameter, with a 1mm spacing between cilia. By optimizing the cilium arrangement and spacing, the interference of the magnetic field superposition effect on the signal can be reduced.

[0029] On the other hand, the sensor array in the high-sensitivity tactile perception system based on the magnetic cilia array includes several groups of three-axis magnetic sensors, which are arranged and fixed on a flexible circuit board; the three-axis magnetic sensors are arranged at intervals.

[0030] Furthermore, the array forms of the sensor array include rectangular array and square array, and the arrangement diagrams of the rectangular array are as follows: Figure 1 As shown, the arrangement diagram of the square array is as follows Figure 2 As shown, the four sensors are arranged horizontally in sequence to form a rectangular array, and the four sensors are arranged in pairs in a cross shape to form a square array. The square array avoids the edge corners of the magnetic cilia array attached above, which can improve the perception accuracy. The array arrangement can realize the coordinated work of multiple sensor units, effectively improving the spatial resolution and information acquisition accuracy of the tactile perception system. Each array consists of several three-axis magnetic sensors, and the circuit connection relationship is as follows Figure 3As shown, it is assumed that the sensor array includes 4 groups of sensors U1-U4 and connector U5, and uses a three-axis magnetic sensor with model MLX90393ELW-ABA-011-RE. The SCL pin of sensor U1 is connected to the power supply VCC (3.3V power supply) through resistor R2 and is connected to the 4th pin of connector U5. The SDA pin of U1 is connected to VCC through resistor R1 and is connected to the 3rd pin of connector U5. The SENB pin and VDD_IO pin of U1 are respectively connected to VCC, and the VDD pin of U1 is connected to VCC and is grounded through capacitor C1. The EP pin, VSS pin, A0 pin and A1 pin of U1 are all grounded; the SCL pin of sensor U2 is connected to the 4th pin of connector U5, the SDA pin is connected to the 3rd pin of connector U5, the SENB pin and VDD_IO pin of U2 are respectively connected to VCC, and the VDD pin of U2 is connected to VCC and is also connected to U2's EP, VSS, A0, and A1 pins are all connected to ground. Sensor U3's SCL pin is connected to pin 4 of connector U5, and its SDA pin is connected to pin 3 of connector U5. U3's SENB, VDD_IO, A0, and A1 pins are each connected to VCC. U3's VDD pin is connected to VCC and also to ground through capacitor C5. U3's EP and VSS pins are also grounded. Sensor U4's SCL pin is connected to pin 4 of connector U5, and its SDA pin is connected to pin 3 of connector U5. U4's SENB, VDD_IO, and A0 pins are each connected to VCC. U4's VDD pin is connected to VCC and also to ground through capacitor C4. U4's EP, VSS, and A1 pins are all grounded. Pins 1, 5, and 6 of connector U5 are all grounded, and pin 2 is connected to VCC and also to ground through capacitor C6. The sensor array can capture multidimensional mechanical changes over a wider range. Connected via a flexible circuit board, it further enhances the system's plasticity and adaptability to complex environments.

[0031] On the other hand, in a specific embodiment, the system further includes a signal acquisition module, 2 C or SPI bus to connector U5 in the sensor array.

[0032] Furthermore, when using I 2 When connecting the sensor array via the I 2 The C multiplexer connects each sensor and connects each sensor to a different channel for polling reading; I 2 The C multiplexer can be model TCA9548A.

[0033] On the other hand, in a specific embodiment, the system also includes a microcontroller, which is connected to the signal acquisition module, receives the collected data and processes it through a dynamic correction algorithm, and then transmits it to a computer or edge device through a serial port or WiFi; the microcontroller accesses each sensor in turn through the signal acquisition module, receives the three-axis magnetic field data of each sensor and adds a timestamp as input for subsequent algorithms.

[0034] Furthermore, a dynamic correction algorithm performs zero-point correction, time-series smoothing, multi-channel alignment, and mutation / noise removal on the three-axis magnetic field data. This dynamic correction algorithm ensures clean, stable, and comparable magnetic field data output, ensuring signal stability when multiple sensors are operating simultaneously.

[0035] On the other hand, in a specific embodiment, finite element analysis (FEA) is used to conduct simulation research to deeply analyze the response behavior of magnetic cilia under different force conditions. In the simulation, a force of 0.5N is applied to the magnetic ciliary array. The results are as follows: Figure 4-7 As shown, Figure 4 A three-dimensional schematic diagram showing the displacement changes of the magnetic ciliary array. Figure 5 Side view showing the displacement changes of the magnetic ciliary array, Figure 6 Shows the stress distribution of the three-dimensional structure of the magnetic ciliary array. Figure 7 Shows the stress distribution of the magnetic ciliary array from the side.

[0036] In displacement simulations, tangential forces were applied to simulate sliding tactile sensations. The results showed significant deformation of the ciliary tips, with high sensitivity to the direction and magnitude of the external force. This displacement change can be sensed and quantified by a Hall effect sensor, which can sense magnetic field changes.

[0037] In stress simulations, when sliding forces act on the ciliary surface, stress is primarily concentrated in the connection area between the ciliary hair and the substrate. To address this, the system optimizes material selection and substrate structure, effectively reducing fatigue risk in stress-concentrated areas and improving the overall durability and service life of the sensor.

[0038] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0039] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-sensitivity tactile sensing system based on a magnetic ciliary array, characterized in that: It includes a magnetic ciliary array and a sensor array. The magnetic ciliary array is attached to the upper surface of the sensor array. The magnetic ciliary array includes a base and a ciliary structure arranged in an orderly manner and fixed on the base. The ciliary structure is made of ecological silicone rubber mixed with magnetic powder.

2. A high-sensitivity tactile perception system based on a magnetic ciliary array according to claim 1, characterized in that: The base material is polydimethylsiloxane.

3. The high-sensitivity tactile perception system based on a magnetic ciliary array according to claim 1, characterized in that: The magnetic powder is neodymium iron boron magnetic powder.

4. The high-sensitivity tactile perception system based on a magnetic ciliary array according to claim 1, characterized in that: The method for preparing a magnetic ciliary structure comprises the following steps: Step 1: Cast the substrate and partially cure; Step 2: Fix the mold on the upper surface of the substrate and fill the mold with eco-silicone rubber mixed with magnetic powder to form the ciliary structure; Step 3: The ciliary structure is solidified and demolded under the action of an external directional magnetic field to form an initial magnetic ciliary structure; Step 4: Use a magnetizer to magnetize the initial magnetic ciliary structure to form an orderly arranged magnetic ciliary array.

5. The high-sensitivity tactile perception system based on a magnetic ciliary array according to claim 4, characterized in that: The mold is made of polymethyl methacrylate.

6. The high-sensitivity tactile perception system based on a magnetic ciliary array according to claim 1, characterized in that: The sensor array includes several groups of three-axis magnetic sensors, which are arranged and fixed on a flexible circuit board; the three-axis magnetic sensors are arranged at intervals.

7. The high-sensitivity tactile perception system based on a magnetic ciliary array according to claim 6, characterized in that: The sensor array can be in the form of a rectangular array or a square array.

8. The high-sensitivity tactile perception system based on a magnetic ciliary array according to claim 1, characterized in that: It also includes a signal acquisition module that connects to the sensor array to collect three-axis magnetic field data.

9. The high-sensitivity tactile perception system based on a magnetic ciliary array according to claim 8, characterized in that: It also includes a microcontroller connected to the signal acquisition module, which receives the collected three-axis magnetic field data and processes it through a dynamic correction algorithm.

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