CN113483921B - Three-dimensional flexible touch sensor - Google Patents

Abstract

The invention discloses a three-dimensional flexible tactile sensor, which comprises a hemispherical raised layer (1), a floating electrode (2), an insulating layer (3), an organic elastomer (4), a pre-structured conductive elastomer (5), a driving Electrode (6), sensing electrode (7), flexible PCB board (8) and substrate (9); the present invention realizes the normal force and slip force from the material magnetic field polarization sensing principle and the sensing unit structure design respectively 3D force detection with self-decoupling.

Description

A three-dimensional flexible tactile sensor

technical field

The invention relates to the field of tactile sensors, in particular to a three-dimensional flexible tactile sensor.

Background technique

Tactile sensors are very important to the development and application of robots, especially service robots and bionic robots. It enables robots to sense the external environment sensitively and accurately, and to achieve safe and natural contact interaction with humans. Not only that, tactile sensors have a wide range of applications in many aspects such as sports training and rehabilitation medicine. However, the existing technology generally realizes the detection of positive pressure (normal force), and most three-dimensional tactile sensors that integrate slip detection have difficulty in decoupling, or even cannot be decoupled.

The magnetic conductive phase filled conductive elastomer can apply a magnetic field during the curing preparation stage due to its magnetorheological effect, so that the spatial distribution of the conductive phase orientation in the same direction as the external force can be obtained microscopically, and then the deformation process of the conductive elastomer under the action of external force In order to realize the large-scale rearrangement effect of the conductive phase on the microscopic scale. This conductive phase rearrangement effect induces the redistribution of conductive channels or microcapacitors on the microscopic scale, thereby causing significant changes in the macroscopic resistance or capacitance, which can realize highly sensitive flexible tactile sensing.

However, when the directional spatial distribution of the conductive phase on the microscopic scale is not the same as the direction of the external force (that is, there is an included angle), its sensitivity will decrease, because the large-scale rearrangement effect of the conductive phase in the direction of the external force on the microscopic scale cannot be induced. And the greater the angle between the spatial distribution direction of the conductive phase orientation and the direction of the external force, the smaller the sensitivity.

Contents of the invention

The purpose of the present invention is to provide a three-dimensional flexible tactile sensor, including floating electrodes, insulating layers, organic elastomers, pre-structured conductive elastomers, driving electrodes, sensing electrodes, flexible PCB boards and substrates.

A hemispherical convex layer is covered on the floating electrode array arranged in M×N.

Several floating electrodes are pasted on the upper surface of the first insulating layer.

The second insulating layer covers the flexible PCB board.

The prestructured conductive elastomer is located between two insulating layers.

The prestructured conductive elastomer includes organic elastomer and several magnetic particles.

The organic elastomer is a hollow cavity.

Several magnetic particles are distributed inside the organic elastomer.

A three-dimensional Cartesian coordinate system is established with the center of gravity of the prestructured conductive elastomer as the coordinate origin. Among them, the part of the prestructured conductive elastomer located at the first hexagram limit and the fifth hexagram limit of the three-dimensional Cartesian coordinate system is recorded as the first subregion, and the part located at the second hexagram limit and the sixth hexagram limit is recorded as the second subregion. In the area, the part of the third hexagram limit and the seventh hexagram limit is recorded as the third sub-region, and the part of the fourth hexagram limit and the eighth hexagram limit is recorded as the fourth sub-region.

When the three-dimensional flexible tactile sensor is in the initial state, the magnetic particles in the first sub-region are inclined to the x+ axis direction, and the inclination angle is denoted as θ _x+ . The magnetic particles in the second sub-region are inclined to the y+ axis direction, and the inclination angle is denoted as θ _y+ . The magnetic particles in the third sub-region are inclined to the x-axis direction, and the inclination angle is denoted as θ _x- . The magnetic particles in the fourth sub-region are inclined to the y-axis direction, and the inclination angle is denoted as θ _y- .

In a floating electrode array, the floating electrode whose projection is located in the first sub-area is denoted as x+ electrode unit, the floating electrode whose projection is located in the second sub-area is denoted as y+ electrode unit, and the floating electrode whose projection is located in the third sub-area is denoted as is an x-electrode unit, and the floating electrode whose projection is located in the fourth sub-region is recorded as a y-electrode unit.

When the three-dimensional flexible tactile sensor is subjected to the gliding force in the x+ axis direction, the inclination angle θ _x- decreases, the overlapping area of the projection of the floating electrode in the x-electrode unit and the corresponding driving electrode and sensing electrode increases, and the inclination angle θ _x+ increases , the overlapping area of the projection of the floating electrode in the x+ electrode unit and the corresponding driving electrode and sensing electrode is reduced.

When the three-dimensional flexible tactile sensor is subjected to the gliding force in the x-axis direction, the inclination angle θ _x- increases, the overlapping area of the projection of the floating electrode in the x-electrode unit and the corresponding driving electrode and sensing electrode decreases, and the inclination angle θ _x+ decreases. Small, the overlapping area of the projection of the floating electrode in the x+ electrode unit and the corresponding driving electrode and sensing electrode increases.

When the three-dimensional flexible tactile sensor is subjected to the gliding force in the y+ axis direction, the inclination angle θ _y- decreases, the overlapping area of the projection of the floating electrode in the y-electrode unit and the corresponding driving electrode and sensing electrode increases, and the inclination angle θ _y+ increases , the overlapping area of the projection of the floating electrode in the y+ electrode unit and the corresponding driving electrode and sensing electrode is reduced.

When the three-dimensional flexible tactile sensor is subjected to the gliding force in the y-axis direction, the inclination angle θ _y- increases, the overlapping area of the projection of the floating electrode in the y-electrode unit and the corresponding driving electrode and sensing electrode decreases, and the inclination angle θ _y+ decreases. Small, the overlapping area of the projection of the floating electrode in the y+ electrode unit and the corresponding driving electrode and sensing electrode increases.

The driving electrodes and the sensing electrodes are bonded to the bottom surface of the organic elastomer.

One driving electrode, one sensing electrode and one floating electrode correspond to each other. Wherein, the driving electrode overlaps with the projection of the floating electrode. The sensing electrodes overlap with the projection of the floating electrode array.

The flexible PCB board is located on the upper surface of the base.

The three-dimensional flexible tactile sensor also includes a hemispherical convex layer covering the floating electrode array arranged in M×N.

A hemispherical raised layer, a floating electrode array arranged in M×N, a pre-structured conductive elastomer, a driving electrode, and a sensing electrode constitute a three-dimensional flexible tactile sensing unit.

In a three-dimensional flexible tactile sensing unit, the projected overlapping areas of the driving electrodes, the sensing electrodes and the floating electrodes are different.

When the three-dimensional flexible tactile sensor is also subjected to a normal force, the prestructured conductive elastomer deforms in the normal direction, and the rearrangement effect of the magnetic particles occurs.

The three-dimensional flexible tactile sensing unit measures the magnitude and direction of the external contact force by generating electric charges at both ends of each floating electrode.

The three-dimensional flexible tactile sensing unit is simultaneously subjected to the gliding force in the x direction and the y direction.

The technical effect of the present invention is unquestionable. The present invention provides a flexible three-dimensional tactile sensor based on a magnetically conductive phase pre-structured elastomer, which realizes the normal force from the principle of material magnetic field polarization sensing and the structural design of the sensing unit. 3D force detection and self-decoupling from sliding forces provide a new option for flexible 3D tactile sensors or electronic skins.

Description of drawings

Figure 1 is a schematic diagram of the three-dimensional tactile sensing based on the sensitivity difference of the conductive elastomer magnetic field pre-structuring; Figure 1(a) is a schematic diagram of the initial state of the x-unit and y-unit; Figure 1(b) is the x+ unit , y+ unit initial state diagram; Figure 1(c) is a schematic diagram of x-unit, y-unit subjected to shear force (x-axis); Figure 1(d) is x+ unit, y+ unit subjected to shear force (x- axis) state diagram; Figure 1(e) is a schematic diagram of the state of x-unit and y-unit under pressure and shear force (x-&z-axis); Figure 1(f) is the state diagram of x+ unit and y+ unit under pressure and shear Schematic diagram of force (x-&z-axis) state.

Fig. 2 is a design diagram of a three-dimensional tactile sensor unit;

Fig. 3 is the structural diagram I of the internal conductive elastomer of the three-dimensional tactile sensor unit;

Fig. 4 is the structural diagram II of the conductive elastomer inside the three-dimensional tactile sensor unit;

Fig. 5 is three-dimensional tactile sensor design diagram I;

Fig. 6 is a three-dimensional tactile sensor design diagram II;

Fig. 7 is a three-dimensional tactile sensor array diagram I;

FIG. 8 is a three-dimensional tactile sensor array diagram II;

In the figure: hemispherical raised layer 1, floating electrode 2, insulating layer 3, organic elastomer 4, prestructured conductive elastomer 5, driving electrode 6, sensing electrode 7, flexible PCB board 8, substrate 9, magnetic particles 10 .

Detailed ways

The present invention will be further described below in conjunction with the examples, but it should not be understood that the scope of the subject of the present invention is limited to the following examples. Without departing from the above-mentioned technical ideas of the present invention, various replacements and changes made according to common technical knowledge and conventional means in this field shall be included in the protection scope of the present invention.

Example 1:

Referring to Figures 1 to 8, a three-dimensional flexible tactile sensor includes a floating electrode 2, an insulating layer 3, an organic elastomer 4, a pre-structured conductive elastomer 5, a driving electrode 6, a sensing electrode 7, a flexible PCB board 8 and a substrate 9.

A layer of hemispherical protrusion layer 1 covers the floating electrode array arranged in M×N. M=2=N.

Several floating electrodes 2 are pasted on the upper surface of the first insulating layer 3 .

The second insulating layer 3 is covered on the flexible PCB 8 .

The pre-structured conductive elastomer 5 is located between two insulating layers 3 .

The prestructured conductive elastomer 5 includes an organic elastomer 4 and several magnetic particles 10.

The organic elastomer 4 is a hollow cavity.

The organic elastomer is a matrix (insulating, insensitive to external force), and the magnetic particles (metal, conductive) inside are dispersed inside, and then it becomes a conductive elastomer (external force causes a strain process, and the resistance or capacitance will be change, has a certain conductivity). The so-called pre-structured conductive elastomer refers to polarizing the magnetic particles that are generally randomly distributed in the organic elastic matrix into a directional distribution, which is called the pre-structuring of the spatial distribution structure of the magnetic particles, and the corresponding entire material is called pre-structured. Structured conductive elastomer.

When this conductive elastomer is compressed by an external force, the relative position of the internal conductive particles will change dynamically, and the distance between adjacent particles, the facing area, etc. will also change, then the conductivity will change, and the macroscopic performance will be capacitance. , The resistance changes. This is the sensing mechanism. The key of the present invention is to realize the detection of three-dimensional force, and it can be self-decoupling, so it relies on a special phenomenon discovered in the early stage, that is, the sensitivity is also related to the pre-structuring direction (arrangement/polarization direction) of the particles.

Several magnetic particles 10 are distributed inside the organic elastomer 4 .

A three-dimensional Cartesian coordinate system is established with the center of gravity of the prestructured conductive elastomer 5 as the coordinate origin. Among them, the part of the prestructured conductive elastomer 5 located at the first hexagram limit and the fifth hexagram limit of the three-dimensional Cartesian coordinate system is recorded as the first sub-region, and the part located at the second hexagram limit and the sixth hexagram limit is recorded as the second subregion. In the sub-region, the part of the third hexagram limit and the seventh hexagram limit is recorded as the third sub-region, and the part of the fourth hexagram limit and the eighth hexagram limit is recorded as the fourth sub-region. The part where the x+ axis, y+ axis, and z+ axis are located is the first hexagram limit, the part where the x-axis, y+ axis, and z+ axis are located is the second hexagram limit, and the part where the x-axis, y-axis, and z+ axis are located is the third hexagram limit , where the x+ axis, y-axis, and z+ axis are located is the fourth hexagram limit, where the x+ axis, y+ axis, and z-axis are located is the fifth hexagram limit, and where the x-axis, y+ axis, and z-axis are located is the sixth hexagram limit. The hexagram limit, where the x-axis, y-axis, and z-axis are located is the seventh hexagram limit, and the part where the x+ axis, y-axis, and z-axis is located is the eighth hexagram limit.

When the three-dimensional flexible tactile sensor is in the initial state, the magnetic particles 10 in the first sub-region are inclined to the x+ axis direction, and the inclination angle is denoted as θ _x+ . The magnetic particles 10 in the second sub-region are inclined to the y+ axis direction, and the inclination angle is denoted as θ _y+ . The magnetic particles 10 in the third sub-region are inclined to the x-axis direction, and the inclination angle is denoted as θ _x- . The magnetic particles 10 in the fourth sub-region are inclined to the y-axis direction, and the inclination angle is denoted as θ _y- . θ _x+ and θ _y+ can be equal, and θ _x- and θ _y- can be equal.

The magnetic particles 10 in the third sub-region are inclined to the y-axis direction, and the inclination angle is denoted as θ _y- . The magnetic particles 10 in the fourth sub-region are inclined to the x-axis direction, and the inclination angle is denoted as θ _x- .

In a floating electrode array, the floating electrode 2 whose projection is located in the first sub-area is denoted as an x+ electrode unit, the floating electrode 2 whose projection is located in the second sub-area is denoted as a y+ electrode unit, and the floating electrode 2 whose projection is located in the third sub-area is denoted as a y+ electrode unit. The electrode 2 is denoted as an x-electrode unit, and the floating electrode 2 whose projection is located in the fourth sub-region is denoted as a y-electrode unit. The x+ electrode units and y+ electrode units are located in different columns in the same row, and the x-electrode units and y-electrode units are located in different columns in the same row.

When the three-dimensional flexible tactile sensor is subjected to the gliding force in the x+ axis direction, the inclination angle θ _x- decreases, the overlapping area of the projection of the floating electrode in the x-electrode unit and the corresponding driving electrode 6 and sensing electrode 7 increases, and the inclination angle θ _x+ The overlapping area of the projection of the floating electrode in the x+ electrode unit and the corresponding driving electrode 6 and sensing electrode 7 decreases.

When the three-dimensional flexible tactile sensor is subjected to the gliding force in the x-axis direction, the inclination angle θ _x- increases, the overlapping area of the projection of the floating electrode in the x-electrode unit and the corresponding driving electrode 6 and sensing electrode 7 decreases, and the inclination angle θ As _x+ decreases, the overlapping area of the projection of the floating electrode in the x+ electrode unit and the corresponding driving electrode 6 and sensing electrode 7 increases.

When the three-dimensional flexible tactile sensor is subjected to the gliding force in the y+ axis direction, the inclination angle θ _y- decreases, the overlapping area of the projection of the floating electrode in the y-electrode unit and the corresponding driving electrode 6 and sensing electrode 7 increases, and the inclination angle θ _y+ As the value increases, the overlapping area of the projection of the floating electrode in the y+ electrode unit and the corresponding driving electrode 6 and sensing electrode 7 decreases.

When the three-dimensional flexible tactile sensor is subjected to the gliding force in the y-axis direction, the inclination angle θ _y- increases, the overlapping area of the projection of the floating electrode in the y-electrode unit and the corresponding driving electrode 6 and sensing electrode 7 decreases, and the inclination angle θ As _y+ decreases, the overlapping area of the projection of the floating electrode in the y+ electrode unit and the corresponding driving electrode 6 and sensing electrode 7 increases.

The driving electrode 6 and the sensing electrode 7 are attached to the bottom surface of the organic elastomer 5;

One driving electrode 6 , one sensing electrode 7 correspond to one floating electrode 2 . Wherein, the driving electrode 6 overlaps with the projection of the floating electrode 2 . The sensing electrodes 7 overlap with the projection of the floating electrode array.

The flexible PCB 8 is located on the upper surface of the base 9 .

The three-dimensional flexible tactile sensor also includes a hemispherical protrusion layer 1 covering the floating electrode array arranged in M×N.

A hemispherical raised layer 1, a floating electrode array arranged in M×N, a pre-structured conductive elastomer 3, a driving electrode 6, and a sensing electrode 7 constitute a three-dimensional flexible tactile sensing unit.

In a three-dimensional flexible tactile sensing unit, the projected overlapping areas of the driving electrodes 6 , the sensing electrodes 7 and the floating electrodes 2 are different.

When the three-dimensional flexible tactile sensor is also subjected to a normal force, the prestructured conductive elastomer 5 deforms in the normal direction, and the magnetic particles 10 undergo a rearrangement effect.

The three-dimensional flexible tactile sensing unit measures the magnitude and direction of the external contact force by generating electric charges at both ends of each floating electrode 1 .

The three-dimensional flexible tactile sensing unit is simultaneously subjected to the gliding force in the x direction and the y direction.

Example 2:

Referring to FIG. 8 , the method for realizing three-dimensional tactile sensing based on the sensitivity difference of the pre-structured conductive elastomer magnetic field is described as follows. The sensing unit contains a total of 4 sensitive subunits x-, x+, y-, y+, and the 4 sensitive subunits have different pre-structured directions (angles), and the floating electrode 1, the sensing electrode 4, and the driving electrode 5 have Different overlapping features.

In the initial state, there are 4 sensitive subunits in the sensing unit, x _- , x ₊ , y _- , y ₊ , with different pre-structured directions (angle θ), among which x _- , y _- subunits point to their negative direction Tilting, x ₊ , y ₊ subunits are tilted towards their positive direction, and the floating electrode 1, sensing electrode 4, and driving electrode 5 have different overlapping characteristics; taking the sliding force in the x ₊ , y ₊ direction as an example, x _- , In the y _- subunit, θ decreases, and the electrode overlapping area increases; in the x ₊ , y ₊ subunit, θ increases, and the electrode overlapping area decreases, and in this way, high-precision sliding force detection is realized; Figure 1-3 at the same time When subjected to normal force and slip force, the prestructured conductive elastomer 2 deforms in the normal direction, resulting in a rearrangement effect of large-scale magnetic particles 3 , realizing highly sensitive detection of normal force and slip force.

3D force detection based on material pre-structuring:

Taking the detection of slip force in the x direction as an example, the x-unit particle chain is inclined by an angle θ to the x-direction, and the x+ unit particle chain is inclined by the same angle θ to the x+ direction. When there is a sliding force in the x+ direction, the prestructured conductive elastomer 2 deforms in the x+ direction. At this time, the x-unit particle chain deflects to the x+ direction microscopically, and the inclination angle θ decreases; the x+ unit particle chain also moves toward the x+ The direction deflects, but because its initial state is already inclined to the x+ direction, the inclination angle θ continues to increase. The inclination angle θ is determined according to the allowable elastic deformation limit in practical applications, that is, the θ of the particle chains in the subunits is allowed to be reduced to zero at most. According to known principles, when the particle chain cluster pre-structuring direction is close to the normal direction, the pressure-capacitance sensitivity of the pre-structured conductive elastomer 2 will increase significantly, and when it is away from the normal direction, the sensitivity will decrease significantly. Based on this principle, from the material The slip force in the x direction can be determined from the characteristics.

Three-dimensional force detection based on the structural design of the sensing unit:

On the other hand, in the sensing unit structure as designed in FIG. 1 , there are different designs in the overlapping area of the floating electrode 1 , its sensing electrode 4 , and the driving electrode 5 . Also take the detection of slip force in the x direction as an example. When there is a slip force in the x ₊ direction, the prestructured conductive elastomer 2 deforms in the x ₊ direction. During this process, the electrode overlapping area in the x _- unit increases, and the x ₊ unit The overlapping area of the middle electrode is reduced. Based on this principle, the sliding force in the x direction can also be determined from the structural characteristics.

Therefore, the pre-structured features of the sensitive material and the dual design of the electrode structure of the sensitive cell ensure that the capacitance value of the x _- cell capacitor will change significantly (increase), while the capacitance value of the x ₊ cell capacitor will change little (small increase). large and possibly even smaller), thus a highly sensitive detection of the slip force in the x direction can be obtained. By analogy, two corresponding pre-structured subunits y- _and y ₊ are set in the y direction to realize the detection of the slip force in the y direction, and the subunits in the x and y directions jointly realize the detection of the slip force in any direction.

In actual work, the sensor is generally affected by the normal force and the slip force at the same time. In addition to the above process, the normal deformation of the prestructured conductive elastomer 2 leads to a large-scale particle rearrangement effect, which will further increase the slip force. The detection sensitivity of the displacement force is improved, and at the same time, the high-sensitivity detection of the normal force is realized. According to the above analysis, the three-dimensional tactile sensor unit and array based on magnetic field prestructured conductive elastomer can be designed.

Claims (5)

1. A three-dimensional flexible tactile sensor, comprising: the device comprises a floating electrode (2), an insulating layer (3), an organic elastomer (4), a pre-structured conductive elastomer (5), a driving electrode (6), an induction electrode (7), a flexible PCB (8) and a substrate (9);

a layer of hemispherical convex layer (1) covers the M multiplied by N floating electrode array;

a plurality of floating electrodes (2) are adhered to the upper surface of the first insulating layer (3);

the second insulating layer (3) covers the flexible PCB (8);

the pre-structured conductive elastomer (5) is located between two insulating layers (3);

the pre-structured conductive elastomer (5) comprises an organic elastomer (4) and a plurality of magnetic particles (10);

the organic elastomer (4) is a hollow cavity;

a plurality of magnetic particles (10) are distributed in the organic elastomer (4);

establishing a three-dimensional Cartesian coordinate system by taking the gravity center point of the pre-structured conductive elastomer (5) as the origin of coordinates; the parts of the pre-structured conductive elastomer (5) positioned in the first divinatory symbols and the fifth divinatory symbols of the three-dimensional Cartesian coordinate system are marked as a first subarea, the parts positioned in the second divinatory symbols and the sixth divinatory symbols are marked as a second subarea, the parts positioned in the third divinatory symbols and the seventh divinatory symbols are marked as a third subarea, and the parts positioned in the fourth divinatory symbols and the eighth divinatory symbols are marked as a fourth subarea;

when the three-dimensional flexible tactile sensor is in an initial state, the magnetic particles (10) in the first sub-region are inclined towards the x + axis direction by the angleIs marked as theta _x+ (ii) a The magnetic particles (10) in the second sub-region are inclined to the y + axis by an angle theta _y+ (ii) a The magnetic particles (10) in the third sub-zone are tilted in the x-axis direction by an angle theta _x- (ii) a The magnetic particles (10) in the fourth sub-region are inclined to the y-axis direction by an angle theta _y- ；

In a floating electrode array, a floating electrode (2) with a projection positioned in a first sub-area is marked as an x + electrode unit, a floating electrode (2) with a projection positioned in a second sub-area is marked as a y + electrode unit, a floating electrode (2) with a projection positioned in a third sub-area is marked as an x-electrode unit, and a floating electrode (2) with a projection positioned in a fourth sub-area is marked as a y-electrode unit;

when the three-dimensional flexible touch sensor is subjected to gliding force in the direction of the x + axis, the inclination angle theta _x- The overlapping area of the projection of the floating electrode in the x-electrode unit and the corresponding driving electrode (6) and the induction electrode (7) is increased, and the inclination angle theta is reduced _x+ The projection of the floating electrode in the x + electrode unit is increased, and the overlapping area of the corresponding driving electrode (6) and the corresponding induction electrode (7) is reduced;

when the three-dimensional flexible touch sensor is subjected to gliding force in the x-axis direction, the inclination angle theta is inclined _x- The overlapping area of the projection of the floating electrode in the x-electrode unit and the corresponding driving electrode (6) and the induction electrode (7) is increased and reduced, and the inclination angle theta is inclined _x+ The overlapping area of the projection of the floating electrode in the x + electrode unit and the corresponding driving electrode (6) and the induction electrode (7) is increased;

when the three-dimensional flexible touch sensor is subjected to gliding force in the y + axis direction, the inclination angle theta is inclined _y- The overlapping area of the projection of the floating electrode in the y-electrode unit and the corresponding driving electrode (6) and the induction electrode (7) is increased, and the inclination angle theta is reduced _y+ Increasing, and reducing the overlapping area of the projection of the floating electrode in the y + electrode unit and the corresponding driving electrode (6) and the induction electrode (7);

when the three-dimensional flexible touch sensor is subjected to gliding force in the y-axis direction, the inclination angle theta is inclined _y- The overlap area of the projection of the floating electrode in the y-electrode unit and the corresponding driving electrode (6) and the induction electrode (7) is reduced, and the inclination angle is increasedDegree theta _y+ The overlapping area of the projection of the floating electrode in the y + electrode unit and the corresponding driving electrode (6) and the induction electrode (7) is increased;

the driving electrode (6) and the induction electrode (7) are attached to the bottom surface of the organic elastomer (4);

a driving electrode (6) and a sensing electrode (7) correspond to a floating electrode (2); wherein the projection of the driving electrode (6) and the floating electrode (2) are overlapped; the sensing electrode (7) is overlapped with the projection of the floating electrode array;

the flexible PCB (8) is positioned on the upper surface of the substrate (9);

the three-dimensional flexible touch sensing unit measures the magnitude and direction of external contact force through the magnitude of charges generated at two ends of each floating electrode (2).

2. The three-dimensional flexible tactile sensor according to claim 1, wherein: the three-dimensional flexible touch sensing unit comprises a hemispherical convex layer (1), a floating electrode array arranged in an M multiplied by N mode, a pre-structured conductive elastomer (5), a driving electrode (6) and an induction electrode (7).

3. The three-dimensional flexible tactile sensor according to claim 2, wherein: in a three-dimensional flexible touch sensing unit, the projection overlapping areas of the driving electrode (6), the sensing electrode (7) and the floating electrode (2) are different.

4. The three-dimensional flexible tactile sensor according to claim 1, wherein: when the three-dimensional flexible touch sensor is simultaneously subjected to normal force, the pre-structured conductive elastomer (5) deforms upwards in the normal direction, and the magnetic particles (10) generate a rearrangement effect.

5. The three-dimensional flexible tactile sensor according to claim 1, wherein: the three-dimensional flexible tactile sensing unit is subjected to gliding forces in the x-direction and the y-direction simultaneously.

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