A resistive-capacitive composite touch sensor, electronic skin and intelligent robot

Abstract

The present invention relates to a resistive-capacitive composite touch sensor, electronic skin and intelligent robot. The touch sensor includes a plurality of sensor units, each of which includes an area contained by four multifunctional layers, and the four multifunctional layers constitute two capacitors for distinguishing the category and proximity of external objects; two layers of electrodes are arranged inside each multifunctional layer, and a piezoresistor for measuring the size and direction of three-dimensional force is arranged between the two layers of electrodes. Its beneficial effects are: the multifunctional layer of the present invention itself can form the electrode of the capacitor, and fully realize the requirements of the contact sense function; the multifunctional layer can also serve as the electromagnetic shielding layer of the internal piezoresistor, so that on the premise of effectively improving the anti-interference ability of three-dimensional force measurement, all the functions of contact sense can be realized; when forming a sensor matrix, the multifunctional layer can be used to realize regional shielding scanning, effectively avoiding the crosstalk problem of adjacent sensor units.

Description

Technical Field

[0001] The present invention relates to a resistive-capacitive composite touch sensor, an electronic skin and an intelligent robot, and is applicable to the technical field of artificial intelligence. Background Art

[0002] In recent years, intelligent robots have developed to a large-scale practical stage in the industrial field. The interaction between intelligent robots and the outside world requires intelligent sensors that imitate various sensory functions of humans, mainly including: visual sensors, auditory sensors, tactile sensors and olfactory sensors. So far, visual sensors and auditory sensors have matured and are widely used in the field of industrial robots. However, as intelligent robots expand into various fields of human activities, especially agricultural robots, household service robots, medical service robots and hotel and catering service robots, robots are required to be able to perform more flexible and complex movements. At the same time, since robots in these fields need to have closer contact with humans, the safety and comfort of contact between robots and humans must be guaranteed. Therefore, highly sensitive tactile sensors with similar human tactile functions are becoming more and more important. Countries around the world have conducted extensive research on bionic tactile sensors.

[0003] Smart tactile sensors should have the following basic functions:

[0004] Contact sense: When the limbs of an intelligent robot are about to or have just touched an external object, it should be able to roughly classify the external object and judge the speed and distance of the external object. For example, a service robot should be able to distinguish whether the object it is about to or has just touched is a human limb or other object, and an agricultural picking robot should be able to distinguish whether the object it is about to or has just touched is fruit, cotton or plant branches and leaves, and should also be able to judge the speed and distance of approach, so that the intelligent robot can properly control the initial speed of its limbs approaching or touching the external object to avoid causing harm to the human body or damage to the object.

[0005] Pressure and sliding sense: When the limbs of the intelligent robot touch an external object, it should be able to sense the size and direction of the three-dimensional pressure applied by the object, so that the intelligent robot can control the three-dimensional pressure applied to the external object within an appropriate range. For example, when a service robot picks up a teacup, it should control the three-dimensional pressure applied to the teacup so that it will not be crushed or slip off. In addition, when the limbs of the intelligent robot slide on an external object, it should be able to sense the direction and speed of the sliding, so that the intelligent robot can control the direction and speed of the sliding. For example, a massage service robot should be able to control the speed and direction of its palm sliding on the human body within an appropriate range.

[0006] Temperature and humidity sense: When the limbs of an intelligent robot approach or touch an external object, it should be able to sense the temperature of the external environment and the external object, so that the intelligent robot can protect its own limbs from damage by high or low temperatures, and protect its service objects from harm by high or low temperatures. For example, when a service robot serves tea to an elderly or patient, it should determine whether the temperature of the tea is suitable for human drinking; when the limbs of an intelligent robot approach flames or high-temperature objects, it should be able to actively avoid them. In addition, when the limbs of an intelligent robot approach or touch an external object, it should be able to sense the humidity of the external environment and the external object, for example, when a household service robot helps humans dry clothes, it should be able to tell whether the clothes have been dried.

[0007] In addition to the above basic functions, since all limbs of the bionic robot need to be covered with a large area of ​​bionic skin with a large number of touch sensors, the intelligent touch sensor also needs to meet the requirements of miniaturization, low power consumption, and easy formation of a sensor matrix.

[0008] Existing research on intelligent touch sensor technology is mainly divided into resistive, capacitive, photoelectric, piezoelectric, inductive, micro-electromechanical and composite (combination of two or more principles) according to the sensing principle. At present, most of them are in the laboratory research stage and have not yet matured to the practical stage. With the deepening of research, more and more research teams are focusing on resistive, capacitive and RC composite types, which are close to maturity due to their simple manufacturing process, low cost and easy mass production.

[0009] Pure resistive touch sensors are based on the principle that flexible piezoresistive variable materials (such as conductive rubber) change their resistivity when subjected to pressure, thereby reflecting the magnitude of the pressure. Its advantages are: it can realize the perception of pressure, that is, three-dimensional force, simple manufacturing process, low cost, strong anti-interference ability, and easy mass production; but its disadvantages are: it is almost impossible to achieve the requirements of contact, it is impossible to classify and identify the objects in contact, it is impossible to judge the speed and distance of approach when it is about to contact an external object, the sensitivity is low, and the product consistency is difficult to control. In some application fields where the requirements for contact and sensitivity are not high, it has certain market potential.

[0010] Capacitive or RC composite touch sensors are the most promising at present. Compared with other forms of touch sensors, capacitive touch sensors have unique advantages in realizing touch sensation. Capacitive touch sensors use electric field theory, and their electric field lines can pass through or touch external objects. They use the characteristics of different objects with different dielectric constants to classify and identify external objects, especially accurately distinguishing whether the external object is a human body or other objects. Capacitive touch sensors also have the advantages of high sensitivity, good consistency, easy production, low cost, and easy matrix realization for realizing pressure and sliding sensations. However, the shortcomings of existing capacitive touch sensor technology are:

[0011] First, it is impossible to meet all the requirements of touch sensors: contact sense, including the classification and identification of external objects and the determination of the degree of proximity of external objects; pressure sense and slip sense, that is, the measurement of the size and direction of three-dimensional force; temperature sense and humidity sense.

[0012] Second, the anti-interference ability is poor and is easily affected by ambient temperature, humidity, and electromagnetic interference. When measuring three-dimensional force, the differential method is usually used to eliminate the influence of ambient temperature and humidity, and the electromagnetic shielding method is used to improve the ability to resist electromagnetic interference. Once the electromagnetic shielding measures are adopted, although the ability to resist electromagnetic interference is effectively improved, the ability to classify and identify external objects and judge the approach speed and distance is lost at the same time, that is, the contact sense function cannot be realized.

[0013] Third, when forming a sensor matrix, electric field crosstalk between adjacent sensor units cannot be avoided.

[0014] In recent years, researchers at home and abroad have published numerous papers and patent documents, which can be roughly divided into the following two categories:

[0015] Sensors that only have pressure and / or slip sensing functions, that is, sensors that can only measure three-dimensional forces, are divided into two subcategories: with shielding measures and without shielding measures: For example:

[0016] Patent application number CN201410245030 discloses a fully flexible capacitive tactile sensor. The patent directly grounds the upper plate of the parallel plate capacitor as a shielding layer. Although this improves the anti-interference ability, the electric field lines inside the shielding layer cannot pass through the shielding layer, thus losing the function of classifying and identifying external objects and the degree of proximity, and cannot achieve touch sensation.

[0017] Patent publication number US2008 / 0174321A1 discloses a capacitive sensor that can simultaneously measure the proximity and sliding sensation of an object. The sensor can work in two modes. The capacitive electrodes of the patent adopt a two-layer structure, and the upper layer is composed of two electrodes to form a planar capacitor, which can realize the function of classifying and identifying external objects for contact sense, but cannot realize the measurement of the proximity of external objects for contact sense. The upper and lower electrodes can form a parallel plate capacitor, which can realize the normal force measurement of pressure sense, but cannot realize the measurement of tangential force. The patent cannot realize any anti-interference measures such as shielding or differential. When forming a matrix, no anti-crosstalk measures can be realized. Summary of the invention

[0018] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a resistive-capacitive composite touch sensor.

[0019] The present invention provides a resistive-capacitive composite touch sensor, characterized in that: the touch sensor comprises a plurality of sensor units, each sensor unit comprises four multifunctional layers, each functional layer comprises a corresponding area, and the four multifunctional layers constitute two capacitors C1 and C2;

[0020] Two layers of electrodes are arranged inside each multifunctional layer, the upper layer is a cross-shaped common electrode, and the lower layer is four independent electrodes corresponding to the upper cross-shaped common electrode. A flexible varistor is arranged between the upper cross-shaped common electrode and the lower independent electrode, one end of the varistor is connected to the upper cross-shaped common electrode, and the other end of the varistor is connected to the lower independent electrode.

[0021] The present invention provides a resistive-capacitive composite touch sensor, which also includes the following auxiliary technical solutions:

[0022] Among them, the first multifunctional layer and the third multifunctional layer are of the same height and are arranged opposite to each other, and the second multifunctional layer and the fourth multifunctional layer are of the same height and are arranged opposite to each other; the center distance between the first multifunctional layer and the third multifunctional layer is d1, the center distance between the second multifunctional layer and the fourth multifunctional layer is d2, and the ratio of d1 to d2 is 1.2-5; the height of the first multifunctional layer and the third multifunctional layer is h1, the height of the second multifunctional layer and the fourth multifunctional layer is h2, and the difference between h1 and h2 is 1-3mm.

[0023] Among them, the area included in each multifunctional layer includes an upper part and a bottom part corresponding to the multifunctional layer, the upper part is composed of a flexible conductive material, and a protective layer composed of a flexible insulating material is arranged on the outside of the flexible conductive material, and the bottom part includes a multi-layer PCB board or FPC board, a flexible insulating layer is arranged under the PCB board or FPC board, a grounding shielding layer controlled by an analog switch is arranged under the flexible insulating layer, and an insulating protective layer is arranged under the grounding shielding layer controlled by the analog switch; a first layer of PCB board or FPC board is provided with an annular electrode corresponding to each multifunctional layer, a second layer of PCB board or FPC board is provided with a circular electrode, and a via is provided on the circular electrode, and the via connects the annular electrode and the circular electrode to form an independent conductive area, and the upper part is electrically connected to the bottom; the upper cross-shaped common electrode is electrically connected to the first layer of PCB board or FPC board through a conductive column arranged inside the multifunctional layer, and the lower independent electrode is directly arranged on the first layer of PCB board or FPC board.

[0024] Wherein, the multifunctional layer is connected to the processor via an analog switch, and the processor is connected to an external circuit;

[0025] The multifunctional layer can shield the sensor in different areas through the time-sharing switching of the analog switch and the control of the bus, wherein each measurement cycle T is composed of two sub-cycles T1 and T2:

[0026] At T1, the first multifunctional layer is connected to the excitation signal of the multifunctional layer, the third multifunctional layer is connected to the analog-to-digital conversion circuit, the second multifunctional layer and the fourth multifunctional layer are grounded at the same time, the analog switch controlling the internal piezoresistors of the first multifunctional layer and the third multifunctional layer is disconnected, and the analog switch controlling the internal piezoresistors of the second multifunctional layer and the fourth multifunctional layer is connected to the common electrode of the internal piezoresistors, so that the capacitor C1 formed by the first multifunctional layer and the third multifunctional layer is not affected by the external crosstalk of the second multifunctional layer and the fourth multifunctional layer, nor by the internal crosstalk of the first multifunctional layer and the third multifunctional layer when realizing the touch sense, and at the same time, the internal piezoresistors of the second multifunctional layer and the fourth multifunctional layer are still in the working state when they are in the shielding state, so as to measure the change of three-dimensional force;

[0027] At T2, the second multifunctional layer is connected to the excitation signal of the multifunctional layer, the fourth multifunctional layer is connected to the analog-to-digital conversion circuit, the first multifunctional layer and the third multifunctional layer are grounded at the same time, the analog switch controlling the internal piezoresistors of the second multifunctional layer and the fourth multifunctional layer is disconnected, and the analog switch controlling the internal piezoresistors of the first multifunctional layer and the third multifunctional layer is connected to the common electrode of the internal piezoresistors, so that the capacitor C2 formed by the second multifunctional layer and the fourth multifunctional layer is not affected by the external crosstalk of the first multifunctional layer and the third multifunctional layer, nor by the internal crosstalk of the second multifunctional layer and the fourth multifunctional layer when realizing the touch sense, and at the same time, the first multifunctional layer and the third multifunctional layer can be in a shielded state, and the internal piezoresistors are still in a working state, so as to measure the change of three-dimensional force;

[0028] In the next T3 cycle, the four multifunctional layers of the sensor unit in the shielding state are grounded at the same time, and the analog switch controlling the internal varistors of the four multifunctional layers is connected to the common electrode of the internal varistors, so that the sensor unit in the shielding state can still measure the changes in three-dimensional force, where T3 = T.

[0029] The measurement period T is 1-20 ms, and T1=T2=0.5T.

[0030] Wherein, the flexible conductive material is an organic conductive silver paste material, and a conductive silver paste bonding layer is provided between the organic conductive silver paste material and the multifunctional layer.

[0031] The upper and bottom parts of the multifunctional layer are electrically connected by bonding or crimping with conductive adhesive; the conductive column is electrically connected to the first layer PCB board or FPC board by welding, crimping or conductive adhesive.

[0032] Among them, the varistor is made of force-sensitive conductive rubber piezoresistive material; the combination of the multifunctional layer and the varistor can realize the temperature sensing function; when the ambient temperature rises, the resistance value of the varistor decreases; when the ambient temperature decreases, the resistance value of the varistor increases, so that the change in temperature can be calculated based on the change in the resistance value of the varistor.

[0033] The present invention also provides an electronic skin, characterized in that it comprises a resistive-capacitive composite touch sensor as described in any one of the above items.

[0034] The present invention also provides an intelligent robot, characterized in that it comprises the electronic skin as described above.

[0035] The present invention also provides an artificial intelligence prosthesis, characterized in that it includes the electronic skin as described above.

[0036] The implementation of the present invention includes the following technical effects:

[0037] A resistive-capacitive composite touch sensor of the present invention can fully realize all functional requirements of the touch sensor with the help of a multifunctional layer: first, the multifunctional layer itself can form a capacitor electrode to fully realize the contact sense functional requirements; second, the multifunctional layer can serve as an electromagnetic shielding layer for a plurality of rectangular flexible varistors contained therein, thereby effectively improving the anti-interference capability of three-dimensional force measurement while also realizing all the contact sense functions; third, when a sensor matrix is ​​formed, the multifunctional layer can be used to realize regional shielding scanning, effectively avoiding the crosstalk problem of adjacent sensor units. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a structural diagram of the appearance of the sensor unit of the present invention.

[0039] Figure 2 This is a layout diagram of a multifunctional layer according to one embodiment of the present invention.

[0040] Figure 3 This is a layout diagram of a multifunctional layer according to another embodiment of the present invention.

[0041] Figure 4 This is a layout diagram of a multifunctional layer according to another embodiment of the present invention.

[0042] Figure 5 A layered diagram of the sensor unit of the present invention.

[0043] Figure 6 FIG. 4 is an exploded view of a string sensor unit in one embodiment of the present invention.

[0044] Figure 7 This is the electric field line distribution diagram of the multifunctional layer of the present invention.

[0045] Figure 8 This is the electric field line distribution diagram when the external object does not enter the electric field line distribution area of ​​the capacitors C1 and C2 of the present invention.

[0046] Fig. 9 This is the electric field line distribution diagram when the external object enters the electric field line distribution area of ​​the capacitor C1 but does not enter the electric field line distribution area of ​​the capacitor C2 according to the present invention.

[0047] Fig.10 This is the electric field line distribution diagram when an external object enters the electric field line distribution area of ​​capacitors C1 and C2 of the present invention.

[0048] Fig.11 This is a distribution diagram of electric field lines when an external object of the present invention contacts capacitor C1 but does not contact capacitor C2.

[0049] Fig.12 This is a diagram of the electric field line distribution when an external object of the present invention contacts capacitors C1 and C2 at the same time.

[0050] Fig.13 Matrix scan diagram of a traditional sensor.

[0051] Fig.14 This is a scanning diagram of the regional shielding matrix of the present invention.

[0052] Fig.15 2 is a cross-sectional view of a multifunctional area in one embodiment of the present invention.

[0053] Fig.16 FIG. 4 is a structural diagram of a parallel plate capacitor in one embodiment of the present invention.

[0054] Fig.17 FIG. 1 is a schematic diagram of a parallel plate capacitor when no force is applied in an embodiment of the present invention.

[0055] Fig.18 FIG. 1 is a schematic diagram of a parallel plate capacitor subjected to a normal force in one embodiment of the present invention.

[0056] Fig.19 FIG. 1 is a schematic diagram of a parallel plate capacitor subjected to shear force in one embodiment of the present invention.

[0057] Fig. 20 FIG. 1 is a schematic diagram of a parallel plate capacitor subjected to a sliding force in one embodiment of the present invention.

[0058] Fig.21 A circuit control diagram in one embodiment of the present invention.

[0059] Fig. 22 FIG. 4 is an equivalent circuit diagram of a sensor unit in an embodiment of the present invention.

[0060] Fig.23 is a cross-sectional view of a multifunctional layer in another embodiment of the present invention.

[0061] Fig.24 for Fig.23 Partial exploded view.

[0062] Fig.25 FIG. 1 is a schematic diagram of a varistor expanding due to heat in another embodiment of the present invention.

[0063] Fig.26 This is a schematic diagram of the varistor shrinking when it is cooled in another embodiment of the present invention.

[0064] Fig. 27 FIG. 4 is an equivalent circuit diagram of a sensor unit in another embodiment of the present invention. DETAILED DESCRIPTION

[0065] The present invention will be described in detail below in conjunction with embodiments and drawings. It should be pointed out that the described embodiments are only intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention.

[0066] like Figure 1 As shown, this embodiment provides a resistive-capacitive composite touch sensor, the touch sensor includes a plurality of sensor units, each sensor unit includes four multifunctional layers, each functional layer includes a corresponding area, and the four multifunctional layers are arranged opposite to each other in pairs, and can be arranged at any angle with the intersection of two pairs of central connecting lines as the center of the circle. Figure 2 As shown, the four multifunctional layers are arranged orthogonally, that is, arranged at an angle of 90 degrees; Figure 3 As shown, the four multifunctional layers are arranged horizontally, that is, arranged at an angle of 0 degrees; Figure 4 As shown, the four multifunctional layers are arranged at a 45-degree angle.

[0067] like Figure 5 , 6As shown, each multifunctional layer includes a corresponding area including an upper portion 11 and a bottom portion corresponding to the multifunctional layer, the upper portion 11 is made of a flexible conductive material, a protective layer 12 made of a flexible insulating material is arranged outside the flexible conductive material, and the bottom portion includes a multilayer PCB board or FPC board, a flexible insulating layer 17 is arranged below the PCB board or FPC board, a ground shielding layer 18 controlled by an analog switch is arranged below the flexible insulating layer 17, and an insulating protective layer 19 is arranged below the ground shielding layer 18 controlled by the analog switch; the first layer PCB board or FPC board 14 is provided with There is a ring electrode 141 corresponding to each multifunctional layer, a circular electrode 151 is arranged on the second layer PCB board or FPC board 15, and a via 152 is arranged on the circular electrode 151. The via 152 is used to connect the ring electrode 141 and the circular electrode 151 to form an independent conductive area. The upper part 11 composed of flexible conductive material and the second layer PCB board or FPC board 15 form a complete multifunctional layer. Since the thickness of a single layer PCB board or FPC board is only 0.025mm, it can fully meet the need of the multifunctional layer to function as a shielding layer. The electronic devices of the touch sensor unit are arranged on the lower surface 162 of the third layer PCB board or FPC board 16. The upper surface 161 and the lower surface 162 of the third layer PCB board or FPC board 16 are used for electronic circuit wiring; Figure 6 As shown, a flexible insulating material 13 is filled inside the corresponding area of ​​each multifunctional layer, and the flexible insulating material 13 insulates the upper and lower electrodes and the multifunctional layers from each other; the upper cross-shaped common electrode 6 is electrically connected to the first PCB board or FPC board through a central conductive column 20 arranged inside the multifunctional layer, and the lower independent electrode 7 is directly arranged on the first PCB board or FPC board 141; the distance between the upper cross-shaped common electrode and the lower independent electrode is 0.5-3mm.

[0068] Preferably, the volume of the sensor unit is 1 mm 3 -100mm 3 .

[0069] Preferably, the ground shielding layer 18 controlled by the analog switch is made of organic silicon conductive silver paste material, and the insulating protection layer 19 is made of PDMS material.

[0070] Preferably, the flexible conductive material is an organic conductive silver paste material, and the organic conductive silver paste material is bonded to the multifunctional layer via conductive silver paste.

[0071] Preferably, the upper part 11 and the bottom of the multifunctional layer are electrically connected by bonding or crimping with conductive adhesive; the conductive column 20 is electrically connected to the first layer PCB board or FPC board 141 by welding, crimping or conductive adhesive.

[0072] For the sake of convenience, this embodiment takes horizontal arrangement as an example. Figure 7 As shown, among the four multifunctional layers of this embodiment, the first multifunctional layer 1 and the third multifunctional layer 3 constitute capacitor C1, and the second multifunctional layer 2 and the fourth multifunctional layer 4 constitute capacitor C2. The long dashed line in the figure represents the electric field distribution of capacitor C1, and the short dashed line represents the electric field distribution of capacitor C2. The first multifunctional layer 1 and the third multifunctional layer 3 are higher than the second multifunctional layer 2 and the fourth multifunctional layer 4, and the center distance between the first multifunctional layer 1 and the third multifunctional layer 3 is greater than that between the second multifunctional layer 2 and the fourth multifunctional layer 4. This arrangement makes the electric field line distribution area of ​​capacitor C1 higher than the electric field line distribution area of ​​capacitor C2. Figure 8 As shown, when the external object 5 does not enter the electric field line distribution area of ​​capacitors C1 and C2, the medium of the electric field line distribution area of ​​capacitors C1 and C2 is air, and the capacitance values ​​of capacitors C1 and C2 will change in proportion to the changes in ambient temperature and humidity. This characteristic of geometric change can be eliminated by digital differential algorithm. Fig. 9 As shown in FIG. 1 , when an external object 5 enters the electric field line distribution area of ​​capacitor C1 but does not enter the electric field line distribution area of ​​capacitor C2, the capacitance of capacitor C1 will change due to the different dielectric constants of objects made of different materials. The change in capacitance of C1 is approximately proportional to the dielectric constant of the external object, and the capacitance of C2 remains unchanged. Fig.10 As shown, when the external object 5 enters the electric field line distribution area of ​​C1 and C2 at the same time, the change in capacitance of C1 and C2 is proportional to the dielectric constant of the object. The dielectric constant, approach distance and speed of the external object can be calculated based on the relationship between the change in C1 and C2 and the change time, thereby realizing the classification and identification of the external object 5 and the proximity judgment function.

[0073] It should be noted that, in this embodiment, the bottom of the multifunctional layer disposed inside each sensor unit is disposed on the same plane, and therefore, the capacitor provided in this embodiment can be regarded as a quasi-planar capacitor.

[0074] like Fig.11 As shown in FIG. 1 , when the external object 5 has just touched the relatively high first multifunctional layer 1 and the third multifunctional layer 3 of the sensor unit, but has not yet touched the relatively low second multifunctional layer 2 and the fourth multifunctional layer 4, the detection units inside the first multifunctional layer 1 and the third multifunctional layer 3 are subjected to force, while the detection units inside the second multifunctional layer 2 and the fourth multifunctional layer 4 are not subjected to force, and thus no change occurs. When the external object 5 further applies pressure to the sensor unit, as shown in FIG. Fig.12 As shown, the detection units inside the second multifunctional layer 2 and the fourth multifunctional layer 4 also change due to pressure. Based on this, the moment of contact with the external object can be further accurately determined, and the speed of the external object contacting the sensor surface can be accurately calculated.

[0075] The RC composite touch sensor provided in this embodiment can realize the regional shielded sensor matrix scanning function through analog switch and bus synchronous control when multiple touch sensor units form a sensor matrix (for intelligent bionic skin) to avoid mutual crosstalk between adjacent sensor units during matrix scanning.

[0076] The capacitance matrix scanning method of the prior art is as follows Fig.13 As shown, the row scan line is connected to the excitation signal through a multi-way switch, and the column scan line is connected to the capacitance input measurement channel through a multi-way switch. When a row and a column are selected, for example, the second row and the second column, the excitation signal on the selected row will be applied to the capacitance excitation electrodes of all columns at the same time, and only the capacitance input stage of the selected column will be connected to the capacitance measurement channel, but at this time, the excitation electrodes of the capacitors on the adjacent columns that are not selected on the selected row will generate crosstalk to the selected capacitor. In addition, the excitation signal on the connecting line on the selected row will also cause crosstalk to the selected capacitor.

[0077] The area-based shielding scanning method of this embodiment is as follows: Fig.14 As shown, the sensor unit in the measurement state selected by the SPI bus through the address bit is marked as O; the sensor unit with no specified address bit is marked as X ground shielding, so it will not cause crosstalk to the selected sensor unit. The selected sensor unit, its four multi-functional layers form two capacitors to realize the tactile function, and its excitation signal comes from the inside of the sensor unit. When the sensor unit is used as a ground shielding unit, its four multi-functional layers are grounded at the same time, and the size of the shielding area, that is, the number of units that are grounded and shielded, can be selected according to actual needs. When the sensor unit is used as a ground shielding unit, its multi-functional layer temporarily loses the function of contact sense, but the unit for three-dimensional force measurement inside each multi-functional layer is still in normal working state to ensure that it still has pressure and sliding sense functions. Since the four multi-functional layers of the unselected sensor unit are all grounded, it will not cause crosstalk to the adjacent selected units.

[0078] Example 1

[0079] In this embodiment, the detection unit inside the multifunctional layer for detecting three-dimensional force is a parallel plate capacitor.

[0080] The parallel plate capacitor structures inside the four multifunctional layers on each sensor unit are the same. To simplify the description, only the internal structure of the first multifunctional layer 1 is taken as an example for description.

[0081] like Fig.15 , 16As shown in Figures 21 and 22, the upper cross-shaped common electrode 6 of the first multifunctional layer 1 forms four parallel plate capacitors C3, C4, C5, and C6 with the four corresponding rectangular independent electrodes 7 in the lower layer, the upper cross-shaped common electrode 6 of the second multifunctional layer 2 forms four parallel plate capacitors C7, C8, C9, and C10 with the four corresponding rectangular independent electrodes 7 in the lower layer, the upper cross-shaped common electrode 6 of the third multifunctional layer 3 forms four parallel plate capacitors C11, C12, C13, and C14 with the four corresponding rectangular independent electrodes 7 in the lower layer, and the upper cross-shaped common electrode 6 of the fourth multifunctional layer 4 forms four parallel plate capacitors C15, C16, C17, and C18 with the four rectangular independent electrodes 7 in the lower layer; wherein the common electrode 6 is connected to the excitation signal, and the rectangular electrodes 7 are respectively connected to four capacitance analog-to-digital conversion channels.

[0082] For the convenience of explanation, only the parallel plate capacitors C4 and C5 composed of the upper cross-shaped common electrode 6 and the lower rectangular electrode 7 are taken as an example for explanation.

[0083] like Fig.17 As shown in the figure, when there is no external force, the distance between the two plates of the parallel plate capacitor C4 is a1, and the area between the two plates is s1. The distance between the two plates of the parallel plate capacitor C5 is a2, and the area between the two plates is s2, where a1=a2, s1=s2, so the capacitance values ​​of the parallel plate capacitors C4 and C5 are also equal. When subjected to the normal pressure of the external object 5, as shown in the figure, Fig.18 As shown in FIG. 1 , the distance a1 between the two plates of the parallel plate capacitor C4 and the distance a2 between the two plates of the parallel plate capacitor C5 are changed, so that the capacitance values ​​of the parallel plate capacitors C4 and C5 are changed. Based on this, the magnitude and direction of the normal force can be determined. When the tangential force of the external object 5 is applied, as shown in FIG. Fig.19 As shown, the area s1 between the two plates of the parallel plate capacitor C4 and the area s2 between the two plates of the parallel plate capacitor C5 are changed, so that the capacitance values ​​of the parallel plate capacitors C4 and C5 are changed. Based on this, the magnitude of the tangential force can be determined; and the direction of the tangential force can be determined based on the difference in the change in the capacitance values ​​of the parallel plate capacitors C4 and C5. Specifically, when the tangential force is Fig.19 When the tangential force is in the direction indicated by the arrow, the absolute value of the capacitance change of the parallel plate capacitor C4 is greater than the absolute value of the capacitance change of the parallel plate capacitor C5. Fig.19When the tangential force is applied in the opposite direction to that indicated by the arrow in the middle, the absolute value of the capacitance change of the parallel plate capacitor C4 is smaller than the absolute value of the capacitance change of the parallel plate capacitor C5. It can be seen that the direction of the tangential force applied to the sensor can be determined based on the difference in the capacitance change of the parallel plate capacitor C4 and the parallel plate capacitor C5 in this embodiment. When the sensor is subjected to a sliding force, such as Fig. 20 As shown, the normal force and tangential force on the parallel plate capacitor C4 and the parallel plate capacitor C5 will vibrate, causing the distance a1 between the two plates of the parallel plate capacitor C4 and the distance a2 between the two plates of the parallel plate capacitor C5, as well as the facing area s1 between the two plates of the parallel plate capacitor C4 and the facing area s2 between the two plates of the parallel plate capacitor C5 to change, thereby causing the capacitance of the parallel plate capacitor C4 and the parallel plate capacitor C5 to fluctuate. The sliding speed and direction are determined accordingly.

[0084] In this embodiment, the multifunctional layer covers the outside of the upper cross-shaped common electrode and the lower independent electrode; wherein the shape of the multifunctional layer can be hemispherical or ellipsoidal, etc.;

[0085] The multifunctional layer is used to realize electromagnetic shielding function for the parallel plate capacitor inside it. There are two ways to realize electromagnetic shielding: ground shielding and equipotential shielding;

[0086] By switching the analog switch of the multifunctional layer to the ground position, the multifunctional layer can be grounded to achieve grounding shielding for external electromagnetic signals; by switching the analog switch of the multifunctional layer to the excitation signal corresponding to the common electrode of the parallel plate capacitor, the multifunctional layer and the common electrode of the parallel plate capacitor form an equipotential to achieve equipotential shielding for external electromagnetic signals.

[0087] Specifically, the multifunctional layer of this embodiment is connected to the processor via an analog switch, and the processor is connected to the external circuit via a bus;

[0088] The multifunctional layer can realize the function of shielding the sensor in different areas through the time-sharing switching of the analog switch and the control of the bus. When performing the area scanning:

[0089] like Fig.21 As shown, the sensor unit in the scanning state performs the following T-period operation; wherein one measurement period T is composed of two sub-periods T1 and T2:

[0090] At T1, the analog switch K1 of the first multifunctional layer 1 is connected to the multifunctional layer excitation signal S1, the analog switch K3 of the third multifunctional layer 3 is connected to the analog-to-digital conversion circuit M1, the analog switch K2 of the second multifunctional layer 2 and the analog switch K4 of the fourth multifunctional layer 4 are grounded at the same time, or the analog switch K2 of the second multifunctional layer 2 is connected to the excitation signal S2-1 of the common electrode 6 of its internal parallel plate capacitor, and the analog switch K4 of the fourth multifunctional layer 4 is connected to the excitation signal S4-1 of the common electrode 6 of its internal parallel plate capacitor, and the analog switch K1-1 of the internal parallel plate capacitor of the first multifunctional layer 1 and the analog switch K3-1 of the internal parallel plate capacitor of the third multifunctional layer 3 are both disconnected, so that the circuit When realizing the sense of contact, the capacitor C1 is not affected by the external crosstalk of the second multifunctional layer 2 and the fourth multifunctional layer 4, nor by the crosstalk of the internal parallel plate capacitors of the first multifunctional layer 1 and the third multifunctional layer 3; at the same time, the analog switch K2-1 for controlling the internal parallel plate capacitor of the second multifunctional layer 2 is connected to the excitation signal S2-1 of the common electrode 6 of the internal parallel plate capacitor, and the analog switch K4-1 for controlling the internal parallel plate capacitor of the fourth multifunctional layer 4 is connected to the excitation signal S4-1 of the common electrode 6 of the internal parallel plate capacitor, so that the second multifunctional layer 2 and the fourth multifunctional layer 4 are in a shielded state, and the internal parallel plate capacitors thereof can still be in a working state, so as to measure the change of three-dimensional force;

[0091] At time T2, the analog switch K2 of the second multifunctional layer 2 is connected to the multifunctional layer excitation signal S2, the analog switch K4 of the fourth multifunctional layer 4 is connected to the analog-to-digital conversion circuit M2, the analog switch K1 of the first multifunctional layer 1 and the analog switch K3 of the third multifunctional layer 3 are grounded at the same time, or the analog switch K1 of the first multifunctional layer 1 is connected to the excitation signal S1-1 of the common electrode 6 of its parallel plate capacitor, the analog switch K3 of the third multifunctional layer 3 is connected to the excitation signal S3-1 of the common electrode 6 of its internal parallel plate capacitor, and the analog switch K2-1 of the internal parallel plate capacitor of the second multifunctional layer and the analog switch K4-1 of the internal parallel plate capacitor of the fourth multifunctional layer are both disconnected, so that the capacitor C 2 When realizing the sense of touch, it is not affected by the external crosstalk of the first multi-functional layer 1 and the third multi-functional layer 3, nor by the crosstalk of the internal parallel plate capacitors of the second multi-functional layer 2 and the fourth multi-functional layer 4; at the same time, the analog switch K1-1 for controlling the internal parallel plate capacitor of the first multi-functional layer 1 is connected to the excitation signal S1-1 of the common electrode 6 of the internal parallel plate capacitor, and the analog switch K3-1 for controlling the internal parallel plate capacitor of the third multi-functional layer 3 is connected to the excitation signal S3-1 of the common electrode 6 of the internal parallel plate capacitor, so that the first multi-functional layer 1 and the third multi-functional layer 3 are in a shielded state, and the internal parallel plate capacitors can still be in a working state to measure the change of three-dimensional force;

[0092] The sensor unit in the shielding state performs the following T3 cycle operation; where T3 = T:

[0093] At T3, the analog switches K1, K2, K3, and K4 of the four multifunctional layers of the sensor unit in the shielding state are grounded at the same time, or the analog switches K1, K2, K3, and K4 of the four multifunctional layers are connected to the excitation signals S1-1, S2-1, S3-1, and S4-1 of the common electrodes 6 of the internal parallel plate capacitors at the same time, and the analog switches K1-1, K2-1, K3-1, and K4-1 that control the common electrodes of the internal parallel plate capacitors of the four multifunctional layers are connected to the excitation signals S1-1, S2-1, S3-1, and S4-1 of the corresponding common electrodes 6 of the parallel plate capacitors at the same time, so that the sensor unit in the shielding state can measure the changes in three-dimensional force.

[0094] like Fig. 22 As shown, the capacitance measurement of this embodiment adopts the 7150 chip of ad1 company, the processor adopts the 32-bit processor of ARM-m0 core, and the external communication adopts SPI bus.

[0095] Preferably, the measurement period T is 1-20 ms, and T1=T2=0.5T.

[0096] Preferably, the combination of the multifunctional layer and the parallel plate capacitor can realize the temperature sensing function. In fact, the parallel plate capacitor used to measure three-dimensional force can be directly used to measure temperature. The change in ambient temperature can cause the medium between the parallel plate capacitors to expand or contract, thereby changing the distance between the parallel plate capacitors, resulting in a change in capacitance. However, since the existing touch sensors do not have a multifunctional layer, they cannot distinguish whether the change in capacitance is caused by the pressure of an external object or by a temperature change, and therefore cannot directly use parallel plate capacitors to realize the temperature sensing of the touch sensor. This embodiment uses the multifunctional layer to accurately determine whether an external object is contacting the touch sensor. When no external object is contacting the touch sensor, due to the electromagnetic shielding effect of the multifunctional layer, the only factor that causes the change in the internal parallel plate capacitance can only be temperature. Figure 8 , 25 As shown in , when the ambient temperature rises, the flexible insulating material between the parallel plate capacitors will expand, causing the distance between the parallel plate capacitors to increase, thereby making the capacitance values ​​of the four parallel plate capacitors smaller year on year; conversely, Fig.26 As shown, when the ambient temperature decreases, the flexible insulating material between the parallel plate capacitors will shrink, causing the spacing between the parallel plate capacitors to become smaller, thereby making the capacitance values ​​of the four parallel plate capacitors larger year-on-year, and the temperature change can be inferred based on the change in capacitance.

[0097] like Fig.11 As shown in FIG. 1 , when an external object 5 contacts the touch sensor, due to the height difference between the two pairs of multifunctional layers, the higher first multifunctional layer 1 and the third multifunctional layer 3 are first subjected to pressure, while the lower second multifunctional layer 2 and the fourth multifunctional layer 4 are not yet subjected to pressure. Fig.25As shown in FIG. 1 , if the temperature of the external object 5 is higher than the ambient temperature, due to the effect of thermal sensing, the flexible insulating material between the internal parallel plate capacitor plates of the second multifunctional layer 2 and the fourth multifunctional layer 4 which are not subjected to pressure will expand due to heat, thereby causing their capacitance to decrease year-on-year; on the contrary, Fig.26 As shown in FIG. 1 , if the temperature of the external object 5 is lower than the ambient temperature, due to the effect of thermal sensing, the flexible insulating material between the parallel plate capacitor plates of the second multifunctional layer and the fourth multifunctional layer that are not subjected to pressure will shrink, causing their capacitance to increase year-on-year. Therefore, the temperature of the external object in contact can be inferred based on the change in the capacitance of the parallel plate capacitors in the second multifunctional layer 2 and the fourth multifunctional layer.

[0098] Preferably, the measurement range of the parallel plate capacitance is 0.001 pf-100 pf.

[0099] Preferably, the first multifunctional layer 1 and the third multifunctional layer 3 are of the same height and are arranged opposite to each other, and the second multifunctional layer 2 and the fourth multifunctional layer 4 are of the same height and are arranged opposite to each other; the center distance between the first multifunctional layer 1 and the third multifunctional layer 3 is d1, the center distance between the second multifunctional layer 2 and the fourth multifunctional layer 4 is d2, and the ratio of d1 to d2 is 1.2-5; the height of the first multifunctional layer 1 and the third multifunctional layer 3 is h1, the height of the second multifunctional layer 2 and the fourth multifunctional layer 4 is h2, and the difference between h1 and h2 is 1-3mm.

[0100] Example 2

[0101] In this embodiment, the detection unit inside the multifunctional layer for detecting three-dimensional force is a piezoresistor.

[0102] like Figure 23-26 As shown, the structure and function of the multifunctional layer are the same as those of the multifunctional layer in Example 1. However, the structure for measuring three-dimensional force inside the multifunctional layer is changed from a parallel plate capacitor to a piezoresistor, the electrode structure inside the multifunctional layer remains unchanged, but four rectangular flexible piezoresistors 21 are added between the upper cross-shaped common electrode 6 and the lower rectangular independent electrode 7. The upper cross-shaped common electrode 6 and the lower four rectangular independent electrodes serve as the two poles of the piezoresistors 21. When subjected to normal force, the four piezoresistors 21 are subjected to the same deformation pressure, and when subjected to tangential force and sliding force, the four piezoresistors 21 are subjected to different deformation pressures. The change of three-dimensional force can be measured according to the change of the four resistors.

[0103] Preferably, the combination of the multifunctional layer and the piezoresistors 21 can also realize the temperature sensing function. When the temperature changes, the four piezoresistors used to measure the three-dimensional force inside the multifunctional layer will also be affected by the temperature change, resulting in a change in resistance, thereby also realizing the temperature sensing function. The measurement principle is similar to the principle of measuring temperature by a parallel plate capacitor; when the ambient temperature rises, the resistance of the piezoresistors 21 decreases; when the ambient temperature decreases, the resistance of the piezoresistors 21 increases, thereby calculating the temperature change based on the change in the resistance of the piezoresistors. Specifically, the piezoresistors 21 are made of conductive rubber piezoresistive material. The force-sensitive conductive rubber piezoresistive material is a polymer material made by uniformly distributing carbon or other highly conductive particles into an insulating flexible polymer matrix material using a specific process. The conductivity of the piezoresistive material depends on the density of the conductive particles inside. When the piezoresistive material is deformed by pressure, the density of the conductive particles inside it will also change, thereby changing the resistance at both ends of the sensor. According to the change in resistance, the change in three-dimensional force inside the multifunctional layer can be measured.

[0104] like Fig. 27 As shown, the multifunctional layer is connected to the processor via an analog switch, and the processor is connected to the external circuit via a bus; the functions of the multifunctional layer controlled by the analog switch and the varistor inside the multifunctional layer are periodically switched in time-sharing manner; wherein a measurement period T is composed of two sub-periods T1 and T2:

[0105] During the T1 cycle, the analog switch K1 of the first multifunctional layer 1 connects the first multifunctional layer 1 to the multifunctional layer excitation signal S1, and the analog switch K3 of the third multifunctional layer 3 connects the third multifunctional layer 3 to the capacitor analog-to-digital conversion circuit m1, so that the first multifunctional layer 1 and the third multifunctional layer 3 form a capacitor C1, the analog switch K2 of the second multifunctional layer 2 and the analog switch K4 of the fourth multifunctional layer 4 are grounded at the same time, and the analog switch K1-1 that controls the internal varistor 21 of the first multifunctional layer 1 and the analog switch K3-1 that controls the internal varistor 21 of the third multifunctional layer 3 are simultaneously The circuit is open, so that the capacitor C1 is not affected by external crosstalk from the second multifunctional layer 2 and the fourth multifunctional layer 4, nor by internal crosstalk from the first multifunctional layer 1 and the third multifunctional layer 3 when realizing contact sensation. At the same time, the analog switch K2-1 that controls the internal varistor 21 of the second multifunctional layer 2 and the analog switch K4-1 that controls the internal varistor 21 of the fourth multifunctional layer 4 are connected to the common electrode 6 of the varistor 21 inside them, so that the internal varistors of the second multifunctional layer 2 and the fourth multifunctional layer 4 are still in working state when they are in shielding state, and can still measure changes in three-dimensional force.

[0106] During the T2 cycle, the analog switch K2 of the second multifunctional layer 2 connects the second multifunctional layer 2 to the multifunctional layer excitation signal S2, and the analog switch K4 of the fourth multifunctional layer 4 connects the fourth multifunctional layer 4 to the capacitor analog-to-digital conversion circuit m2, so that the second multifunctional layer 2 and the fourth multifunctional layer 4 form a capacitor C2, the analog switch K1 of the first multifunctional layer 1 and the analog switch K3 of the third multifunctional layer 3 are grounded at the same time, and the analog switch K2-1 that controls the internal varistor 21 of the second multifunctional layer 2 and the analog switch K4-1 that controls the internal varistor 21 of the fourth multifunctional layer 4 are grounded at the same time. The circuit is open at the same time, so that the capacitor C2 is not affected by the external crosstalk of the first multifunctional layer 1 and the third multifunctional layer 3, nor the internal crosstalk of the second multifunctional layer 2 and the fourth multifunctional layer 4 when realizing the touch sense. At the same time, the analog switch K1-1 controlling the internal varistor 21 of the first multifunctional layer 1 and the analog switch K3-1 controlling the internal varistor 21 of the third multifunctional layer 3 are connected to the common electrode 6 of the varistor 21 inside them, so that the first multifunctional layer 1 and the third multifunctional layer 3 are in a shielding state and the internal varistors are in a working state, and the changes in three-dimensional force can still be measured.

[0107] The time of the measurement cycle T should be controlled between 1 and 20 ms, T1 = T2 = 1 / 2T.

[0108] When performing a regional matrix scan, the sensor units selected to be in the measuring state execute the above T cycle, and the sensor units selected as the shielding area execute a special cycle T3.

[0109] The analog switches K1, K2, K3, and K4 of the four multifunctional layers of the sensor unit in the shielding state are grounded, and at the same time, the analog switches K1-1, K2-1, K3-1, and K4-1 that control the internal varistors 21 of the four multifunctional layers are connected to the cross-shaped common electrode 6 of the internal varistors 21, so that the sensor unit in the shielding state can measure the changes in three-dimensional force.

[0110] like Fig. 27 As shown, the capacitance measurement of this embodiment adopts the 7150 chip of ad1 company, the processor adopts the 32-bit processor of ARM-m0 core, and the external communication adopts SPI bus.

[0111] Preferably, the measurement period T is 1-20 ms, and T1=T2=0.5T.

[0112] Another aspect of the present application is an electronic skin including the above-mentioned RC composite touch sensor. Since the improvement only involves the sensor on the artificial skin, other components can adopt relatively mature technologies in the prior art. Therefore, the present application will not describe other components of the electronic skin.

[0113] Another aspect of the present application also relates to an intelligent robot including the above-mentioned electronic skin. Since the improvement only involves the contact sensor on the artificial skin, and other components can adopt relatively mature technologies in the prior art, the present application will not describe other components of the intelligent robot.

[0114] Another aspect of the present application also relates to an artificial intelligence prosthesis including the above-mentioned electronic skin. Since the improvement only involves the contact sensor on the artificial skin, other components can adopt relatively mature technologies in the prior art. Therefore, this application will not describe other components of the artificial intelligence prosthesis.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A resistive-capacitive composite touch sensor, characterized in that: The touch sensor includes a plurality of sensor units, each of which includes four multifunctional layers, each of which includes a corresponding area, and the four multifunctional layers constitute two capacitors C1 and C2 for classifying and identifying external objects and determining proximity; Two layers of electrodes are arranged inside each multifunctional layer, the upper layer is a cross-shaped common electrode, and the lower layer is four independent electrodes corresponding to the upper cross-shaped common electrode, and a varistor is arranged between the upper cross-shaped common electrode and the lower independent electrode, one end of the varistor is connected to the upper cross-shaped common electrode, and the other end of the varistor is connected to the lower independent electrode; The multifunctional layer serves as an electrode for realizing touch sense and as an electromagnetic shielding layer for its internal varistor. The multifunctional layer controlled by the analog switch and the varistor inside the multifunctional layer are switched in time sharing. The varistor inside the multifunctional layer in the shielding state is in the working state.

2. The RC composite touch sensor according to claim 1, characterized in that: The first multifunctional layer and the third multifunctional layer are of the same height and are arranged opposite to each other, and the second multifunctional layer and the fourth multifunctional layer are of the same height and are arranged opposite to each other; the center distance between the first multifunctional layer and the third multifunctional layer is d1, the center distance between the second multifunctional layer and the fourth multifunctional layer is d2, and the ratio of d1 to d2 is 1.2-5; the height of the first multifunctional layer and the third multifunctional layer is h1, the height of the second multifunctional layer and the fourth multifunctional layer is h2, and the difference between h1 and h2 is 1-3mm.

3. The RC composite touch sensor according to claim 1 or 2, characterized in that: The area included in each multifunctional layer includes an upper part and a bottom part corresponding to the multifunctional layer, the upper part is made of a flexible conductive material, a protective layer made of a flexible insulating material is arranged on the outside of the flexible conductive material, the bottom part includes a multi-layer PCB board or FPC board, a flexible insulating layer is arranged under the PCB board or FPC board, a grounding shielding layer controlled by an analog switch is arranged under the flexible insulating layer, and an insulating protective layer is arranged under the grounding shielding layer controlled by the analog switch; a first layer of PCB board or FPC board is provided with an annular electrode corresponding to each multifunctional layer, a second layer of PCB board or FPC board is provided with a circular electrode, a via is provided on the circular electrode, the via connects the annular electrode and the circular electrode to form an independent conductive area, and the upper part is electrically connected to the bottom; the upper cross-shaped common electrode is electrically connected to the first layer of PCB board or FPC board through a conductive column arranged inside the multifunctional layer, and the lower independent electrode is directly arranged on the first layer of PCB board or FPC board.

4. The RC composite touch sensor according to claim 1 or 2, characterized in that: The multifunctional layer is connected to a processor via an analog switch, and the processor is connected to an external circuit; The multifunctional layer shields the sensor in different areas through time-sharing switching of analog switches and control of the bus, wherein each measurement cycle T consists of two sub-cycles T1 and T2: At T1, the first multi-functional layer is connected to the multi-functional layer excitation signal, the third multi-functional layer is connected to the analog-to-digital conversion circuit, the second multi-functional layer and the fourth multi-functional layer are grounded at the same time, the analog switches controlling the internal varistors of the first multi-functional layer and the third multi-functional layer are disconnected, and the analog switches controlling the internal varistors of the second multi-functional layer and the fourth multi-functional layer are connected to the common electrodes of the internal varistors; At T2, the second multi-functional layer is connected to the multi-functional layer excitation signal, the fourth multi-functional layer is connected to the analog-to-digital conversion circuit, the first multi-functional layer and the third multi-functional layer are grounded at the same time, the analog switches controlling the internal varistors of the second multi-functional layer and the fourth multi-functional layer are disconnected, and the analog switches controlling the internal varistors of the first multi-functional layer and the third multi-functional layer are connected to the common electrodes of the internal varistors; In the next T3 cycle, the four multifunctional layers of the sensor unit in the shielding state are grounded at the same time, and the analog switch controlling the internal varistors of the four multifunctional layers is connected to the common electrode of the internal varistors, so that the sensor unit in the shielding state can still measure the changes in three-dimensional force, where T3 = T.

5. The RC composite touch sensor according to claim 4, characterized in that: The measurement period T is 1-20 ms, and T1 = T2 = 0.5T.

6. The RC composite touch sensor according to claim 3, characterized in that: The flexible conductive material is an organic conductive silver paste material, and a conductive silver paste bonding layer is provided between the organic conductive silver paste material and the multifunctional layer.

7. The RC composite touch sensor according to claim 6, characterized in that: The upper and bottom parts of the multifunctional layer are electrically connected by bonding or crimping with conductive adhesive; the conductive column is electrically connected to the first layer PCB board or FPC board by welding, crimping or conductive adhesive.

8. An electronic skin, characterized in that: It comprises a resistive-capacitive composite touch sensor as described in any one of claims 1-7.

9. An intelligent robot, characterized in that: Comprising the electronic skin as described in claim 8.

10. An artificial intelligence prosthesis, characterized in that: Comprising the electronic skin as described in claim 8.

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